Chemical inclusions significantly alter shock responses of crystalline explosives in macroscale gap experiments but their microscale dynamics origin remains unclear.Herein shock-induced energy localization,overall phy...Chemical inclusions significantly alter shock responses of crystalline explosives in macroscale gap experiments but their microscale dynamics origin remains unclear.Herein shock-induced energy localization,overall physical responses,and reactions in a-1,3,5-trinitro-1,3,5-triazinane(a-RDX)crystal entrained various chemical inclusions were investigated by the multi-scale shock technique implemented in the reactive molecular dynamics method.Results indicated that energy localization and shock reaction were affected by the intrinsic factors within chemical inclusions,i.e.,phase states,chemical compositions,and concentrations.The atomic origin of chemical-inclusions effects on energy localization is dependent on the dynamics mechanism of interfacial molecules with free space volume,which includes homogeneous intermolecular compression,interfacial impact and shear,and void collapse and jet.As introducing various chemical inclusions,the initiation of those dynamics mechanisms triggers diverse decay rates of bulk RDX molecules and hereby impacts on growth speeds of final reactions.Adding chemical inclusions can reduce the effectiveness of the void during the shock impacting.Under the shockwave velocity of 9 km/s,the parent RDX decay rate in RDX entrained amorphous carbon decreases the most and is about one fourth of that in RDX with a vacuum void,and solid HMX and TATB inclusions are more reactive than amorphous carbon but less reactive than dry air or acetone inclusions.The lessdense shocking system denotes the greater increases in local temperature and stress,the faster energy liberation,and the earlier final reaction into equilibrium,revealing more pronounced responses to the present intense shockwave.The quantitative models associated with the relative system density(RD_(sys))were proposed for indicating energy-localization mechanisms and evaluating initiation safety in the shocked crystalline explosive.RD_(sys)is defined by the density ratio of defective RDX to perfect crystal after dynamics relaxation and reveals the global density characteristic in shocked systems filled with chemical inclusions.When RD_(sys)is below 0.9,local hydrodynamic jet initiated by void collapse dominates upon energy localization instead of interfacial impact.This study sheds light on novel insights for understanding the shock chemistry and physical-based atomic origin in crystalline explosives considering chemical-inclusions effects.展开更多
It is generally believed that the lithospheric mantle and the mantle transition zone are important carbon reservoirs.However,the location of carbon storage in Earth's interior and the reasons for carbon enrichment...It is generally believed that the lithospheric mantle and the mantle transition zone are important carbon reservoirs.However,the location of carbon storage in Earth's interior and the reasons for carbon enrichment remain unclear.In this study,we report CO_(2)-rich olivine-hosted melt inclusions in the mantle xenoliths of late Cenozoic basalts from the Penglai area,Hainan Province,which may shed some light on the carbon enrichment process in the lithospheric mantle.We also present a detailed petrological and geochemical investigation of the late Cenozoic basalts and mantle xenoliths from northern Hainan Island.The collected samples of late Cenozoic Hainan Island basalts belong to both alkaline and subalkaline series,showing fractionated REE patterns with high(La/Yb)_(N)values of 3.52–11.77,which are typical for OIB.Based on Al-in-olivine thermometry,the temperatures estimated for the mantle xenoliths can be divided into two groups.One group has temperatures of less than 1050℃,and the other group has temperature ranging from 1050℃to 1282℃.Clinopyroxene(La/Yb)_(N)–Ti/Eu and clinopyroxene Ca/Al–Mg^(#)diagrams indicate that the mantle peridotite experienced metasomatism from both silicate and carbonate melts.Melt inclusions in the olivine of mantle xenoliths include(1)CO_(2)bubble–rich melt inclusions;(2)multiphase melt inclusions(glass+CO_(2)bubble+daughter minerals);(3)pure glass melt inclusions.Magnesite is a daughter mineral in the olivine-hosted melt inclusions,which could be interpreted as a secondary mineral formed by the interactions of CO_(2)-rich fluids with an olivine host,due to post-entrapment effects.The glasses in olivine-hosted melt inclusions have high SiO_(2)contents(60.21–77.72 wt%).Our results suggest that a considerable amount of CO_(2)-rich melt inclusions are captured in the lithospheric mantle during metasomatism.The lithospheric mantle can therefore act as is a‘carbon trap',with much CO_(2)being absorbed by the lithospheric mantle in this way.展开更多
With the development of artificial intelligence,stiffness sensors are extensively utilized in various fields,and their integration with robots for automated palpation has gained significant attention.This study presen...With the development of artificial intelligence,stiffness sensors are extensively utilized in various fields,and their integration with robots for automated palpation has gained significant attention.This study presents a broad range self-powered stiffness sensor based on the triboelectric nanogenerator(Stiff-TENG)for variable inclusions in soft objects detection.The Stiff-TENG employs a stacked structure comprising an indium tin oxide film,an elastic sponge,a fluorinated ethylene propylene film with a conductive ink electrode,and two acrylic pieces with a shielding layer.Through the decoupling method,the Stiff-TENG achieves stiffness detection of objects within 1.0 s.The output performance and characteristics of the TENG for different stiffness objects under 4 mm displacement are analyzed.The Stiff-TENG is successfully used to detect the heterogeneous stiffness structures,enabling effective recognition of variable inclusions in soft object,reaching a recognition accuracy of 99.7%.Furthermore,its adaptability makes it well-suited for the detection of pathological conditions within the human body,as pathological tissues often exhibit changes in the stiffness of internal organs.This research highlights the innovative applications of TENG and thereby showcases its immense potential in healthcare applications such as palpation which assesses pathological conditions based on organ stiffness.展开更多
In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric s...In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.展开更多
In order to understand the geochemical characteristics of Paleozoic reservoir fluids in Xuanjing region,Lower Yangtze area,drilling core samples from Y and D wells were tested and analyzed to study the fluid inclusion...In order to understand the geochemical characteristics of Paleozoic reservoir fluids in Xuanjing region,Lower Yangtze area,drilling core samples from Y and D wells were tested and analyzed to study the fluid inclusion types and composition.Pressure correction was undertaken to determine the temperature and pressure environment for inclusion formation,and the influence of fluid characteristics of the Upper Permian and Lower Triassic reservoirs on the preservation of shale gas was investigated.According to petrograph-ic observations,fluid inclusions are mainly brine and bitumen inclusions.Bitumen inclusions are mainly distributed in holes and fractures,and with smaller individuals.No visible fluorescence was observed,and the vitrinite reflectance is 3.39%–3.92%.This indicates that there had been oil and gas accumulation in the early stage of diagenesis in the study area,but due to the influence of magmatic hydrothermal solution,oil and gas underwent thermal metamorphism in the early stage,making liquid petroleum into solid bitumen.At present,oil and gas in the reservoir were largely formed in the late stage.During the continuous process in which shale was buried,light oil and gas were generated.Light oil and gas underwent magmatic and tectonic hydrothermal processes in some areas,resulting in high-temperature metamorphic cracking that formed dry gas.Moreover,nitrogen inclusions are found in fluid inclusions,forming metamorphic fluids caused by mag-matic hydrothermal activities.The study shows that Paleozoic reservoirs in Xuanjing area are characterized by self-generation and self-storage.Furthermore,the mechanism of shale gas accumulation is not only related to the buried hydrocarbon generation process of shale itself,but is also related to later magmatic activity and tectonic hydrothermal transformation.Therefore,preservation conditions are generally key factors of shale gas accumulation in this area.展开更多
The specific distribution characteristics of inclusions along with the sliver defect were analyzed in detail to explain the formation mechanism of the sliver defect on the automobile exposed panel surface.A quantitati...The specific distribution characteristics of inclusions along with the sliver defect were analyzed in detail to explain the formation mechanism of the sliver defect on the automobile exposed panel surface.A quantitative electrolysis method was used to compare and evaluate the three-dimensional morphology,size,composition,quantity,and distribution of inclusions in the defect and non-defect zone of automobile exposed panel.The Al2O3 inclusions were observed to be aggregated or chain-like shape along with the sliver defect of about 3–10μm.The aggregation sections of the Al2O3 inclusions are distributed discretely along the rolling direction,with a spacing of 3–7 mm,a length of 6–7 mm,and a width of about 3 mm.The inclusion area part is 0.04%–0.16%with an average value of 0.08%,the inclusion number density is 40 mm−2 and the inclusion average spacing is 25.13μm.The inclusion spacing is approximately 40–160μm,with an average value of 68.76μm in chain-like inclusion parts.The average area fraction and number density of inclusions in the non-defect region were reduced to about 0.002%and 1–2 mm^−2,respectively,with the inclusion spacing of 400μm and the size of Al2O3 being 1–3μm.展开更多
Mold flux serves the crucial metallurgical function of absorbing inclusions, directly impacting the smoothness of the casting process as well as the cast slab quality. In this study, the dissolution behavior and mecha...Mold flux serves the crucial metallurgical function of absorbing inclusions, directly impacting the smoothness of the casting process as well as the cast slab quality. In this study, the dissolution behavior and mechanism of Ti O_(2)and Ti N inclusions in molten Ca O–Si O_(2)–B_(2)O_(3)-based fluorine-free mold flux were explored by in situ single hot thermocouple technology combined with X-ray photoelectron spectroscopy.The results showed that Ti O_(2) inclusions are effectively dissolved by the molten slag within 76 s, during which the original octahedral [Ti O_(6)]^(8-)structures are destroyed and convert to the networker tetrahedral [Ti O_(4)]^(4-)structures. However, the dissolution rate is much lower for Ti N inclusions than for Ti O_(2)inclusions. This can be attributed to the fact that the Ti N particles need to be oxidized and then dissolved in the molten slag to form tetrahedral [Ti O4]4-and octahedral [Ti O_(6)]^(8-)structures during the Ti N inclusion dissolution process, which is accompanied by the generation of a large amount of N_(2)gas. Moreover, Ca Ti O_(3)crystals tend to nucleate and grow on bubble surfaces with sufficient octahedral [Ti O_(6)]^(8-)structures and Ca^(2+)ions, eventually resulting in the molten slag being in a solid–liquid mixed state.展开更多
To shed light on the genesis of the Dongping deposit and reveal the behaviour of CO_(2),Au and other ore elements(e.g.,Cu,Fe,Zn,As,Sb,Co etc.)in ore-forming fluids,petrographic,microthermometric and synchrotron radiat...To shed light on the genesis of the Dongping deposit and reveal the behaviour of CO_(2),Au and other ore elements(e.g.,Cu,Fe,Zn,As,Sb,Co etc.)in ore-forming fluids,petrographic,microthermometric and synchrotron radiation X-ray fluorescence(SRXRF)analyses of fluid inclusions were conducted.The ore-forming fluid is characterized as an H_(2)O-CO_(2)-NaCl system with medium-high temperatures and low salinity.Four mineralization stages are identified,namely,feldsparquartz(stage 1);pyrite-white quartz(stage 2);sulfide-smoky grey quartz(stage 3);and carbonate-quartz(stage 4).Three types of inclusions were distinguished,based on fluid composition,phase assemblages and mode of homogenization.Type A:H_(2)O-rich fluid inclusions show 2 phases(liquid H_(2)O(LH_(2)O)+vapour H_(2)O(VH_(2)O))at room temperature and homogenize to the liquid phase.Type B:H_(2)O-CO_(2)fluid inclusions contain 2–3 phases(liquid H_(2)O(LH_(2)O)+vapour CO_(2)(VCO_(2));liquid H_(2)O(LH_(2)O)+liquid CO_(2)(LCO_(2)));liquid H_(2)O(LH_(2)O)+liquid CO_(2)(LCO_(2))+vapour CO_(2)(VCO_(2)))at room temperature and homogenized to the liquid H_(2)O phase.Type C:H_(2)O-CO_(2)fluid inclusions show 2 phases(liquid H_(2)O(LH_(2)O)+liquid CO_(2)(LCO_(2))at room temperature and homogenize to a critical state.CO_(2)is clearly more enriched in the fluid inclusions of stages 2 and 3 than in stage 1.Stage 1 is dominated by type A(H_(2)O-rich)inclusions with homogenization temperatures(Th)of 220–359℃and salinities of 1.1–3.1 wt%NaCl equivalent.Type B(CO_(2)-rich)inclusions gradually increase in stages 2 and 3.The Th range of type B inclusions in stage 2 is 241–397℃with salinities of 2.2–6.9 wt%NaCl equivalent;the Th range of type A inclusions is 217–373℃with salinities of 1.2–8.1 wt%NaCl equivalent.The Th range of type B inclusions in stage 3 is 215–361℃with salinities of 2.9–6.1 wt%NaCl equivalent;the range of type A inclusions is 158–351℃with a salinity of 0.7–5.5 wt%NaCl equivalent.Stage 4 is characterized by type A with Th of 151–250℃and salinities of 0.9–8.3 wt%NaCl equivalent.The mapping results show that elements As,Te and Sb are more concentrated in vapour CO_(2)than in liquid H_(2)O at room temperature,which suggests that vapour components are more able to transport elements when phase separation occurs.The SRXRF quantitative results show that Au,Cl,S and some other metals are obviously more enriched in the fluid inclusions of stages 2 and 3 than those in stage 1.Additionally,the contents of S in stages 1–3 are much lower than those of Cl,which suggests that gold might migrate mainly in the form of a gold-chloride complex.Au is more enriched in type B fluid inclusions than in type A fluid inclusions,which suggests that the enrichment and migration of gold are closely related to CO_(2)and CO_(2)plays a critical role in the migration and enrichment of gold.The trace elements in the fluid have a similar change trend to those in the Yanshanian syenogranite distributed in the southeastern part of the mining area,which may provide some evidence for an intrusion-related genesis for the Dongping gold deposit.展开更多
The Goshgarchay Cu-Au deposit is located in the central part of the northwest flank of the Murovdagh region in the Lesser Caucasus.The Goshgarchay Cu-Au deposit is associated with Middle Jurassic volcanic and Late Jur...The Goshgarchay Cu-Au deposit is located in the central part of the northwest flank of the Murovdagh region in the Lesser Caucasus.The Goshgarchay Cu-Au deposit is associated with Middle Jurassic volcanic and Late Jurassic-Early Cretaceous high-K calc-alkaline intrusive rocks.The Cu-Au mineralization is commonly related to quartz-sericite-chlorite alteration dominantly composed of chalcopyrite,gold,sphalerite,pyrite,bornite,hematite,covellite,chalcocite,malachite,and azurite.The Goshgarchay copper-gold deposit,which is 600 m wide and approximately 1.2 km long,is seen as a faultcontrolled and vein-,stockwork-and disseminated type deposit.The Goshgarchay Cu-Au deposit predominantly comprises Cu(max.64500 ppm)and Au(max.11.3 ppm),while it comprises relatively less amounts Zn(max.437 ppm),Mo(max.47.5 ppm),Pb(max.134 ppm),and Ag(max.21 ppm).The homogenization temperatures and salinities of fluid inclusions in quartz for stage Ⅰ range from 380℃ to 327℃,and 6.9 wt% to 2.6 wt% NaCl eq.,respectively.Thand salinities in quartz for stage Ⅱ range from 304℃ to 253℃,and 7.6 wt% to 3.2 wt% NaCl eq.,respectively.The calculated δ^(34)S_(h2s)values(-1.5‰ to 5.5‰)of sulfides and especially the narrow range of δ^(34)S_(h2s) values of chalcopyrite and bornite(between -0.07‰ and +0.7‰)indicate that the source of the Goshgarchay Cu-Au mineralization is magmatic.Based on the mineralogical,geochemical,fluid inclusion,and sulfur isotopic data,the Goshgarchay Cu-Au deposit represents a late stage peripheral magmatic-hydrothermal mineralization probably underlain by a concealed porphyry deposit.展开更多
Flour serves as one of the primary ingredients of cookies,which affects dough properties,physical changes during baking,and post-baking cookie properties.Two gluten-free cookie formulations were developed with the goa...Flour serves as one of the primary ingredients of cookies,which affects dough properties,physical changes during baking,and post-baking cookie properties.Two gluten-free cookie formulations were developed with the goal of use as inclusions in frozen desserts.Blonde and chocolate cookies were made with sorghum flour or all-purpose wheat flour and then evaluated for physical and chemical properties.To determine functionality in a frozen state,texture analysis was conducted on cookies at−30℃,−17°C,and 20℃,replicating various ice cream storage temperatures.To simulate the process effect of incorporating the product into a frozen dessert,cookies were crumbled mechanically,and the crumbles were separated based on size.When evaluating cookies,no significant differences(P<0.05)were observed in width(W),thickness(T),spread,and W/T ratio for flour source within formula.Blonde cookies had lower moisture contents than chocolate cookies;further,blonde cookies made from sorghum flour had less moisture than those made with wheat flour.As the cookie temperature decreased from 20℃to−17℃,cookie hardness increased,with flour type having no effect.Within formula,cookies had similar instrumental color parameters.However,blonde cookies made from sorghum flour produced more smaller-sized pieces than those made from wheat flour.The results of this study demonstrate that sorghum flour cookies have desirable properties for use as inclusions in ice cream and other frozen desserts.展开更多
The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristi...The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristics of metallogenic period quartz veins were studied to reveal the ore-forming fluid features.Laser Raman analysis indicates that the ore-forming fluids is a H_(2)O-NaCl-CH_(4)(-CO_(2))system.Fluid inclusions microthermometry shows a homogenization temperature of 181-375°C and a salinity of 5.26%-16.99%for the disseminated-banded Cu-Zn mineralization;but a homogenization temperature of 142-343°C and a salinity of 5.41%-21.19%for the massive-veined Cu-Zn mineralization.These features suggest a medium-high temperature and a medium salinity for the ore-forming fluids.H-O isotopic data indicates that the ore-forming fluids were mainly from the metamorphic and magmatic water,plus minor formation water.And sulfur isotopic data indicates that sulfur was mainly derived from the formation and magmatic rocks.Metallogenesis of the disseminated-banded mineralization was mainly correlated with fluid mixing and water-rock reaction;whereas that of the massive-veined mineralization was mainly correlated with fluid boiling.The genetic type of the deposit is a medium-high temperature hydrothermal deposit related to magmatism and controlled by shear zones.This study is beneficial to understand the stratiform copper deposit.展开更多
Al_2O_3 and TiN inclusions in interstitial-free(IF) steel deteriorate the properties of the steel. To decrease the defects of cold-rolled sheet, it is important to clearly distinguish between the degrees of damage cau...Al_2O_3 and TiN inclusions in interstitial-free(IF) steel deteriorate the properties of the steel. To decrease the defects of cold-rolled sheet, it is important to clearly distinguish between the degrees of damage caused by these two inclusions on the surface quality of the steel. In this study, a nanoindenter was used to test the mechanical properties of the inclusions, and the distribution and size of the inclusions were obtained by scanning electron microscopy(SEM). It was found that when only mechanical properties are considered, TiN inclusions are more likely to cause defects than Al_2O_3 inclusions of the same size during the rolling process. However, Al_2O_3 inclusions are generally more inclined to cause defects in the rolling process than TiN inclusions because of their distribution characteristic in the thickness direction. The precipitation of Al_2O_3 and TiN was obtained through thermodynamical calculations. The growth laws of inclusions at different cooling rates were calculated by solidification and segregation models. The results show that the precipitation regularity is closely related to the distribution law of the inclusions in IF slabs along the thickness direction.展开更多
The Al_2O_3, MnS, and TiN inclusions in bearing steel will deteriorate the steel's mechanical properties. Therefore, elucidating detailed characteristics of these inclusions in consumable electrode during the elec...The Al_2O_3, MnS, and TiN inclusions in bearing steel will deteriorate the steel's mechanical properties. Therefore, elucidating detailed characteristics of these inclusions in consumable electrode during the electroslag remelting process is important for achieving a subsequently clean ingot. In this study, a confocal scanning violet laser microscope was used to simulate the remelting process and observe, in real time, the behaviors of inclusions. The obtained images show that, after the temperature exceeded the steel solidus temperature, MnS and TiN inclusions in the specimen began to dissolve. Higher temperatures led to faster dissolution, and the inclusions disappeared before the steel was fully liquid. In the case of an observed Al_2O_3 inclusion, its shape changed from angular to a smooth ellipsoid in the region where the solid and liquid coexisted and it began to dissolve as the temperature continued to increase. This dissolution was driven by the difference in oxygen potential between the inclusion and the liquid steel.展开更多
Many researchers have explored the inclusion modification mechanism to improve non-metallic inclusion modifications in steelmaking. In this study, two types of industrial trials on inclusion modifications in liquid st...Many researchers have explored the inclusion modification mechanism to improve non-metallic inclusion modifications in steelmaking. In this study, two types of industrial trials on inclusion modifications in liquid steel were conducted using ultra-low-carbon Al-killed steel with different Mg and Ca contents to verify the effects of Ca and Mg contents on the modification mechanism of Al_2O_3-based inclusions during secondary refining. The results showed that Al_2O_3-based inclusions can be modified into liquid calcium aluminate or a multi-component inclusion with the addition of a suitable amount of Ca. In addition, [Mg] in liquid steel can further reduce CaO in liquid calcium aluminate to drive its evolution into CaO–MgO–Al_2O_3 multi-component inclusions. Thermodynamic analysis confirmed that the reaction between [Mg] and CaO in liquid calcium aluminate occurs when the MgO content of liquid calcium aluminate is less than 3 wt% and the temperature is higher than 1843 K.展开更多
Industrial experiments were carried out to investigate the formation of CaS-bearing inclusion during Ca double modification in oil casting steels using polished cross sections and electrolytic extraction. Immediately ...Industrial experiments were carried out to investigate the formation of CaS-bearing inclusion during Ca double modification in oil casting steels using polished cross sections and electrolytic extraction. Immediately after Ca addition, the role of newly generated CaS as an intermediate reaction product, which modified the Al_2O_3 inclusion into a liquid calcium aluminate, was confirmed. The formation of transient CaS was attributed to the high surface segregation of S at the liquid steel-calcium vapor interface, where a simple site coverage model based upon the Langmuir adsorption equation was established. Moreover, a CaS outer layer surrounding the liquid calcium aluminate was attained mainly in the tundish, which was distributed unevenly on the surface of liquid particles according to the three-dimensional mapping results. The surface of a well-modified calcium aluminate with higher CaO activity and Al_2O_3 activity under bulk composition conditions in the tundish acted as a favorable site for the generation of CaS. Additionally, CaS could be precipitated directly onto existing inclusions during solidification of the steel, which led to various morphologies of CaS-bearing inclusions in slabs. Furthermore, the phase transformation of inclusions during solidification was strongly influenced both by the S content and the Ca/S ratio in the tundish via thermodynamics.展开更多
For the control of surface defects in interstitial-free(IF) steel, quantitative metallographic analyses of near-surface inclusions and surface liquid flow detection via the nail-board tipping method were conducted. Th...For the control of surface defects in interstitial-free(IF) steel, quantitative metallographic analyses of near-surface inclusions and surface liquid flow detection via the nail-board tipping method were conducted. The results show that, at casting speeds of 0.8 and 1.0 m/min, a thin liquid mold flux layer forms and non-uniform floating of argon bubbles occurs, inducing the entrainment and subsequent entrapment of the liquid flux; fine inclusion particles of Al_2O_3 can also aggregate at the solidification front. At higher casting speeds of 1.4 and 1.6 m/min, the liquid mold flux can be entrained and carried deeper into the liquid steel pool because of strong level fluctuations of the liquid steel and the flux. The optimal casting speed is approximately 1.2 m/min, with the most favorable surface flow status and, correspondingly, the lowest number of inclusions near the slab surface.展开更多
This paper summarizes melting methods of titanium and titanium alloy, such as vacuum arc melting(VAR) and electron beam cold hearth melting(EBCHM), and the related inclusions formed when using these melting methods. L...This paper summarizes melting methods of titanium and titanium alloy, such as vacuum arc melting(VAR) and electron beam cold hearth melting(EBCHM), and the related inclusions formed when using these melting methods. Low-density inclusions are resulted from contamination of air, and high-density inclusions are caused by refractory elements. The formation process of inclusions was analysed. The removal mechanism of different kinds of inclusions was specified. Low-density inclusions are removed mainly by resolving. This is a comprehensive process containing reaction diffusion. The resolving rate of high-density inclusions is so low that these inclusions are mainly removed by sedimentation. The experiments and physical models of inclusions are detailed. In various melting methods, vacuum arc melting is prominent. However, this method cannot remove inclusions effectively, which usually results in repeat melting. Electron beam cold hearth melting has the best ability of removing inclusions. These results can provide instructions to researchers of titanium and titanium alloys.展开更多
Industrial experiments with three types of slags were performed to investigate the effect of slag on oxide inclusions during electroslag remelting(ESR) process. G20CrNi2Mo bearing steel was used as the consumable elec...Industrial experiments with three types of slags were performed to investigate the effect of slag on oxide inclusions during electroslag remelting(ESR) process. G20CrNi2Mo bearing steel was used as the consumable electrode and remelted using a 2400-kg industrial furnace. The results showed that most inclusions in the electrode were low-melting-point CaO-MgO-Al_2O_3. After ESR, all the inclusions in ingots were located outside the liquid region. When the slag consisted of 65.70 wt% CaF_2, 28.58 wt% Al_2O_3, and 4.42 wt% CaO was used, pure Al_2O_3 were the dominant inclusions in ingot, some of which presented a clear trend of agglomeration. When the ingot was remelted by a multi-component slag with 16.83 wt% CaO, a certain amount of sphere CaAl_4O_7 inclusions larger than 5 μm were generated in ingot. The slag with 8.18 wt% CaO exhibited greater capacity to control the inclusion characteristics. Thermodynamic calculations indicated that the total Ca and Mg in ingots were attributed from the relics in electrode and strongly influenced by the slag composition. The formation of ingot inclusions was calculated by FactSage^(TM) 7.0, and the results were basically in accordance with the observed inclusions, indicating that a quasi-thermodynamic equilibrium could be obtained in the metal pool.展开更多
As the substrate for nucleation of primary austenite in hardfacing metals, the effectiveness of RE inclusions and the most common inclusions such as Al2O3, SiO2 and MnO in hardfacing metals of medium-high carbon steel...As the substrate for nucleation of primary austenite in hardfacing metals, the effectiveness of RE inclusions and the most common inclusions such as Al2O3, SiO2 and MnO in hardfacing metals of medium-high carbon steelswas analyzed and calculated in detail. The calculation based on the theory of planar lattice misfit shows that Ce2O3,La2O3 and Ce2O2S, instead of SiO2, Al2O3, MnO and CeS, are effective as the heterogeneous nuclei of primary austenitein medium-high carbon steels.展开更多
The inclusions in large diamond single crystals have effects on its ultimate performance, which restricts its industrial applications to a great extent. Therefore, it is necessary to study the inclusions systematicall...The inclusions in large diamond single crystals have effects on its ultimate performance, which restricts its industrial applications to a great extent. Therefore, it is necessary to study the inclusions systematically. In this paper, large diamond single crystals with different content values of inclusions are synthesized along the(100) surface by the temperature gradient method(TGM) under 5.6 GPa at different temperatures. With the synthetic temperature changing from 1200?C to 1270?C,the shapes of diamonds change from plate to low tower, to high tower, even to steeple. From the microscopic photographs of the diamond samples, it can be observed that with the shapes of the samples changing at different temperatures, the content values of inclusions in diamonds become zero, a little, much and most, correspondingly. Consequently, with the temperature growing from low to high, the content values of inclusions in crystals increase. The origin of inclusions is explained by the difference in growth rate between diamond crystal and its surface. The content values of inclusions in diamond samples are quantitatively calculated by testing the densities of diamond samples. And the composition and inclusion content are analyzed by energy dispersive spectroscopy(EDS) and x-ray diffraction(XRD). From contrasting scanning electron microscopy(SEM) photographs, it can be found that the more the inclusions in diamond, the more imperfect the diamond surface is.展开更多
基金the financial support from National Natural Science Foundation of China(Grant Nos.11872119,12172051,and 11972329)Natural Science Foundation of Hubei Province(Grant No.2021CFB120)。
文摘Chemical inclusions significantly alter shock responses of crystalline explosives in macroscale gap experiments but their microscale dynamics origin remains unclear.Herein shock-induced energy localization,overall physical responses,and reactions in a-1,3,5-trinitro-1,3,5-triazinane(a-RDX)crystal entrained various chemical inclusions were investigated by the multi-scale shock technique implemented in the reactive molecular dynamics method.Results indicated that energy localization and shock reaction were affected by the intrinsic factors within chemical inclusions,i.e.,phase states,chemical compositions,and concentrations.The atomic origin of chemical-inclusions effects on energy localization is dependent on the dynamics mechanism of interfacial molecules with free space volume,which includes homogeneous intermolecular compression,interfacial impact and shear,and void collapse and jet.As introducing various chemical inclusions,the initiation of those dynamics mechanisms triggers diverse decay rates of bulk RDX molecules and hereby impacts on growth speeds of final reactions.Adding chemical inclusions can reduce the effectiveness of the void during the shock impacting.Under the shockwave velocity of 9 km/s,the parent RDX decay rate in RDX entrained amorphous carbon decreases the most and is about one fourth of that in RDX with a vacuum void,and solid HMX and TATB inclusions are more reactive than amorphous carbon but less reactive than dry air or acetone inclusions.The lessdense shocking system denotes the greater increases in local temperature and stress,the faster energy liberation,and the earlier final reaction into equilibrium,revealing more pronounced responses to the present intense shockwave.The quantitative models associated with the relative system density(RD_(sys))were proposed for indicating energy-localization mechanisms and evaluating initiation safety in the shocked crystalline explosive.RD_(sys)is defined by the density ratio of defective RDX to perfect crystal after dynamics relaxation and reveals the global density characteristic in shocked systems filled with chemical inclusions.When RD_(sys)is below 0.9,local hydrodynamic jet initiated by void collapse dominates upon energy localization instead of interfacial impact.This study sheds light on novel insights for understanding the shock chemistry and physical-based atomic origin in crystalline explosives considering chemical-inclusions effects.
基金supported by the National Key Research and Development Project(Grant.No.2019YFA0708503)。
文摘It is generally believed that the lithospheric mantle and the mantle transition zone are important carbon reservoirs.However,the location of carbon storage in Earth's interior and the reasons for carbon enrichment remain unclear.In this study,we report CO_(2)-rich olivine-hosted melt inclusions in the mantle xenoliths of late Cenozoic basalts from the Penglai area,Hainan Province,which may shed some light on the carbon enrichment process in the lithospheric mantle.We also present a detailed petrological and geochemical investigation of the late Cenozoic basalts and mantle xenoliths from northern Hainan Island.The collected samples of late Cenozoic Hainan Island basalts belong to both alkaline and subalkaline series,showing fractionated REE patterns with high(La/Yb)_(N)values of 3.52–11.77,which are typical for OIB.Based on Al-in-olivine thermometry,the temperatures estimated for the mantle xenoliths can be divided into two groups.One group has temperatures of less than 1050℃,and the other group has temperature ranging from 1050℃to 1282℃.Clinopyroxene(La/Yb)_(N)–Ti/Eu and clinopyroxene Ca/Al–Mg^(#)diagrams indicate that the mantle peridotite experienced metasomatism from both silicate and carbonate melts.Melt inclusions in the olivine of mantle xenoliths include(1)CO_(2)bubble–rich melt inclusions;(2)multiphase melt inclusions(glass+CO_(2)bubble+daughter minerals);(3)pure glass melt inclusions.Magnesite is a daughter mineral in the olivine-hosted melt inclusions,which could be interpreted as a secondary mineral formed by the interactions of CO_(2)-rich fluids with an olivine host,due to post-entrapment effects.The glasses in olivine-hosted melt inclusions have high SiO_(2)contents(60.21–77.72 wt%).Our results suggest that a considerable amount of CO_(2)-rich melt inclusions are captured in the lithospheric mantle during metasomatism.The lithospheric mantle can therefore act as is a‘carbon trap',with much CO_(2)being absorbed by the lithospheric mantle in this way.
基金This work is supported by the grant from the National Natural Science Foundation of China under Grants 62104125 and 62311530102,Guangdong Innovative and Entrepreneurial Research Team Program(2021ZT09L197)Guangdong Basic and Applied Basic Research Foundation(2020A1515110887)+1 种基金Tsinghua Shenzhen International Graduate School-Shenzhen Pengrui Young Faculty Program of Shenzhen Pengrui Foundation(No.SZPR2023005)Shenzhen Science and Technology Program(JCYJ20220530143013030).
文摘With the development of artificial intelligence,stiffness sensors are extensively utilized in various fields,and their integration with robots for automated palpation has gained significant attention.This study presents a broad range self-powered stiffness sensor based on the triboelectric nanogenerator(Stiff-TENG)for variable inclusions in soft objects detection.The Stiff-TENG employs a stacked structure comprising an indium tin oxide film,an elastic sponge,a fluorinated ethylene propylene film with a conductive ink electrode,and two acrylic pieces with a shielding layer.Through the decoupling method,the Stiff-TENG achieves stiffness detection of objects within 1.0 s.The output performance and characteristics of the TENG for different stiffness objects under 4 mm displacement are analyzed.The Stiff-TENG is successfully used to detect the heterogeneous stiffness structures,enabling effective recognition of variable inclusions in soft object,reaching a recognition accuracy of 99.7%.Furthermore,its adaptability makes it well-suited for the detection of pathological conditions within the human body,as pathological tissues often exhibit changes in the stiffness of internal organs.This research highlights the innovative applications of TENG and thereby showcases its immense potential in healthcare applications such as palpation which assesses pathological conditions based on organ stiffness.
基金supported by National Natural Science Foundation of China(Nos.52202460,52177128)National Key R&D Program of China(Nos.2020YFC2201100,2021YFC2202804)+2 种基金China Postdoctoral Science Foundation(Nos.2021M690392,2021TQ0036)Science Foundation for Youth Scholars of the Beijing Institute of TechnologyAdvanced Space Propulsion Laboratory of BICE and the Beijing Engineering Research Centre of Efficient and Green Aerospace Propulsion Technology(No.LabASP-2021-04)。
文摘In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.
基金Supported by projects of Fundamental Research Funds for Chinese Academy of Geological Sciences(No.JKYQN202338,No.DZLXJK202208)National Natural Science Foundation of China(No.41802158)the China Geological Survey(No.DD20230023).
文摘In order to understand the geochemical characteristics of Paleozoic reservoir fluids in Xuanjing region,Lower Yangtze area,drilling core samples from Y and D wells were tested and analyzed to study the fluid inclusion types and composition.Pressure correction was undertaken to determine the temperature and pressure environment for inclusion formation,and the influence of fluid characteristics of the Upper Permian and Lower Triassic reservoirs on the preservation of shale gas was investigated.According to petrograph-ic observations,fluid inclusions are mainly brine and bitumen inclusions.Bitumen inclusions are mainly distributed in holes and fractures,and with smaller individuals.No visible fluorescence was observed,and the vitrinite reflectance is 3.39%–3.92%.This indicates that there had been oil and gas accumulation in the early stage of diagenesis in the study area,but due to the influence of magmatic hydrothermal solution,oil and gas underwent thermal metamorphism in the early stage,making liquid petroleum into solid bitumen.At present,oil and gas in the reservoir were largely formed in the late stage.During the continuous process in which shale was buried,light oil and gas were generated.Light oil and gas underwent magmatic and tectonic hydrothermal processes in some areas,resulting in high-temperature metamorphic cracking that formed dry gas.Moreover,nitrogen inclusions are found in fluid inclusions,forming metamorphic fluids caused by mag-matic hydrothermal activities.The study shows that Paleozoic reservoirs in Xuanjing area are characterized by self-generation and self-storage.Furthermore,the mechanism of shale gas accumulation is not only related to the buried hydrocarbon generation process of shale itself,but is also related to later magmatic activity and tectonic hydrothermal transformation.Therefore,preservation conditions are generally key factors of shale gas accumulation in this area.
基金This work was financially supported by the National Natural Science Foundation of China(No.U1960202).
文摘The specific distribution characteristics of inclusions along with the sliver defect were analyzed in detail to explain the formation mechanism of the sliver defect on the automobile exposed panel surface.A quantitative electrolysis method was used to compare and evaluate the three-dimensional morphology,size,composition,quantity,and distribution of inclusions in the defect and non-defect zone of automobile exposed panel.The Al2O3 inclusions were observed to be aggregated or chain-like shape along with the sliver defect of about 3–10μm.The aggregation sections of the Al2O3 inclusions are distributed discretely along the rolling direction,with a spacing of 3–7 mm,a length of 6–7 mm,and a width of about 3 mm.The inclusion area part is 0.04%–0.16%with an average value of 0.08%,the inclusion number density is 40 mm−2 and the inclusion average spacing is 25.13μm.The inclusion spacing is approximately 40–160μm,with an average value of 68.76μm in chain-like inclusion parts.The average area fraction and number density of inclusions in the non-defect region were reduced to about 0.002%and 1–2 mm^−2,respectively,with the inclusion spacing of 400μm and the size of Al2O3 being 1–3μm.
基金financially supported by the Fellowship of China National Postdoctoral Program for Innovative Talents(No.BX20220357)the National Science Foundation of China (No.52130408)。
文摘Mold flux serves the crucial metallurgical function of absorbing inclusions, directly impacting the smoothness of the casting process as well as the cast slab quality. In this study, the dissolution behavior and mechanism of Ti O_(2)and Ti N inclusions in molten Ca O–Si O_(2)–B_(2)O_(3)-based fluorine-free mold flux were explored by in situ single hot thermocouple technology combined with X-ray photoelectron spectroscopy.The results showed that Ti O_(2) inclusions are effectively dissolved by the molten slag within 76 s, during which the original octahedral [Ti O_(6)]^(8-)structures are destroyed and convert to the networker tetrahedral [Ti O_(4)]^(4-)structures. However, the dissolution rate is much lower for Ti N inclusions than for Ti O_(2)inclusions. This can be attributed to the fact that the Ti N particles need to be oxidized and then dissolved in the molten slag to form tetrahedral [Ti O4]4-and octahedral [Ti O_(6)]^(8-)structures during the Ti N inclusion dissolution process, which is accompanied by the generation of a large amount of N_(2)gas. Moreover, Ca Ti O_(3)crystals tend to nucleate and grow on bubble surfaces with sufficient octahedral [Ti O_(6)]^(8-)structures and Ca^(2+)ions, eventually resulting in the molten slag being in a solid–liquid mixed state.
基金funded by a Natural Science Foundation of Hebei Province(Grant No.D2020403019)the Natural Science Foundation of Hebei Province(Grant Nos.D2020403101 and D2019403041)+2 种基金the Science and Technology Project of Hebei Education Department(Grant No.ZD2020134)the National Natural Science Foundation of China(Grant Nos.41702094 and 41672070)the Science and Technology Innovation Team Project of Hebei GEO University(Grant No.KJCXTD-2021-02)。
文摘To shed light on the genesis of the Dongping deposit and reveal the behaviour of CO_(2),Au and other ore elements(e.g.,Cu,Fe,Zn,As,Sb,Co etc.)in ore-forming fluids,petrographic,microthermometric and synchrotron radiation X-ray fluorescence(SRXRF)analyses of fluid inclusions were conducted.The ore-forming fluid is characterized as an H_(2)O-CO_(2)-NaCl system with medium-high temperatures and low salinity.Four mineralization stages are identified,namely,feldsparquartz(stage 1);pyrite-white quartz(stage 2);sulfide-smoky grey quartz(stage 3);and carbonate-quartz(stage 4).Three types of inclusions were distinguished,based on fluid composition,phase assemblages and mode of homogenization.Type A:H_(2)O-rich fluid inclusions show 2 phases(liquid H_(2)O(LH_(2)O)+vapour H_(2)O(VH_(2)O))at room temperature and homogenize to the liquid phase.Type B:H_(2)O-CO_(2)fluid inclusions contain 2–3 phases(liquid H_(2)O(LH_(2)O)+vapour CO_(2)(VCO_(2));liquid H_(2)O(LH_(2)O)+liquid CO_(2)(LCO_(2)));liquid H_(2)O(LH_(2)O)+liquid CO_(2)(LCO_(2))+vapour CO_(2)(VCO_(2)))at room temperature and homogenized to the liquid H_(2)O phase.Type C:H_(2)O-CO_(2)fluid inclusions show 2 phases(liquid H_(2)O(LH_(2)O)+liquid CO_(2)(LCO_(2))at room temperature and homogenize to a critical state.CO_(2)is clearly more enriched in the fluid inclusions of stages 2 and 3 than in stage 1.Stage 1 is dominated by type A(H_(2)O-rich)inclusions with homogenization temperatures(Th)of 220–359℃and salinities of 1.1–3.1 wt%NaCl equivalent.Type B(CO_(2)-rich)inclusions gradually increase in stages 2 and 3.The Th range of type B inclusions in stage 2 is 241–397℃with salinities of 2.2–6.9 wt%NaCl equivalent;the Th range of type A inclusions is 217–373℃with salinities of 1.2–8.1 wt%NaCl equivalent.The Th range of type B inclusions in stage 3 is 215–361℃with salinities of 2.9–6.1 wt%NaCl equivalent;the range of type A inclusions is 158–351℃with a salinity of 0.7–5.5 wt%NaCl equivalent.Stage 4 is characterized by type A with Th of 151–250℃and salinities of 0.9–8.3 wt%NaCl equivalent.The mapping results show that elements As,Te and Sb are more concentrated in vapour CO_(2)than in liquid H_(2)O at room temperature,which suggests that vapour components are more able to transport elements when phase separation occurs.The SRXRF quantitative results show that Au,Cl,S and some other metals are obviously more enriched in the fluid inclusions of stages 2 and 3 than those in stage 1.Additionally,the contents of S in stages 1–3 are much lower than those of Cl,which suggests that gold might migrate mainly in the form of a gold-chloride complex.Au is more enriched in type B fluid inclusions than in type A fluid inclusions,which suggests that the enrichment and migration of gold are closely related to CO_(2)and CO_(2)plays a critical role in the migration and enrichment of gold.The trace elements in the fluid have a similar change trend to those in the Yanshanian syenogranite distributed in the southeastern part of the mining area,which may provide some evidence for an intrusion-related genesis for the Dongping gold deposit.
基金financially supported by the Scientific Research Project Coordination of Konya Technical University(Grant No.211007014)。
文摘The Goshgarchay Cu-Au deposit is located in the central part of the northwest flank of the Murovdagh region in the Lesser Caucasus.The Goshgarchay Cu-Au deposit is associated with Middle Jurassic volcanic and Late Jurassic-Early Cretaceous high-K calc-alkaline intrusive rocks.The Cu-Au mineralization is commonly related to quartz-sericite-chlorite alteration dominantly composed of chalcopyrite,gold,sphalerite,pyrite,bornite,hematite,covellite,chalcocite,malachite,and azurite.The Goshgarchay copper-gold deposit,which is 600 m wide and approximately 1.2 km long,is seen as a faultcontrolled and vein-,stockwork-and disseminated type deposit.The Goshgarchay Cu-Au deposit predominantly comprises Cu(max.64500 ppm)and Au(max.11.3 ppm),while it comprises relatively less amounts Zn(max.437 ppm),Mo(max.47.5 ppm),Pb(max.134 ppm),and Ag(max.21 ppm).The homogenization temperatures and salinities of fluid inclusions in quartz for stage Ⅰ range from 380℃ to 327℃,and 6.9 wt% to 2.6 wt% NaCl eq.,respectively.Thand salinities in quartz for stage Ⅱ range from 304℃ to 253℃,and 7.6 wt% to 3.2 wt% NaCl eq.,respectively.The calculated δ^(34)S_(h2s)values(-1.5‰ to 5.5‰)of sulfides and especially the narrow range of δ^(34)S_(h2s) values of chalcopyrite and bornite(between -0.07‰ and +0.7‰)indicate that the source of the Goshgarchay Cu-Au mineralization is magmatic.Based on the mineralogical,geochemical,fluid inclusion,and sulfur isotopic data,the Goshgarchay Cu-Au deposit represents a late stage peripheral magmatic-hydrothermal mineralization probably underlain by a concealed porphyry deposit.
基金The authors would like to extend an expression of gratitude to the USDA for analyzing particle sizes on the two flour samples.Masters'candidate Janae Brown in the Food Science Institute at Kansas State University(Manhattan,KS,USA)assisted in taking pictures for this publication.The authors acknowledge support from the Kansas State University Research and Extension,publication number 23-087-J.Mention of trade names or commercial products in this publication is solely for providing specific information and does not imply recommendation or endorsement by the U.S.Department of Agriculture.The USDA is an equal opportunity provider and employer.This work was supported in part by the U.S.Department of Agriculture,Agricultural Research Service.
文摘Flour serves as one of the primary ingredients of cookies,which affects dough properties,physical changes during baking,and post-baking cookie properties.Two gluten-free cookie formulations were developed with the goal of use as inclusions in frozen desserts.Blonde and chocolate cookies were made with sorghum flour or all-purpose wheat flour and then evaluated for physical and chemical properties.To determine functionality in a frozen state,texture analysis was conducted on cookies at−30℃,−17°C,and 20℃,replicating various ice cream storage temperatures.To simulate the process effect of incorporating the product into a frozen dessert,cookies were crumbled mechanically,and the crumbles were separated based on size.When evaluating cookies,no significant differences(P<0.05)were observed in width(W),thickness(T),spread,and W/T ratio for flour source within formula.Blonde cookies had lower moisture contents than chocolate cookies;further,blonde cookies made from sorghum flour had less moisture than those made with wheat flour.As the cookie temperature decreased from 20℃to−17℃,cookie hardness increased,with flour type having no effect.Within formula,cookies had similar instrumental color parameters.However,blonde cookies made from sorghum flour produced more smaller-sized pieces than those made from wheat flour.The results of this study demonstrate that sorghum flour cookies have desirable properties for use as inclusions in ice cream and other frozen desserts.
基金financially supported by National Natural Science Foundation of China(42272106,41202067)Open Fund of State Key Laboratory for Mineral Deposits Research,Nanjing University(2019-LAMD-K12)China Geological Survey(DD20211386,DD20211392,DD20179603).
文摘The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristics of metallogenic period quartz veins were studied to reveal the ore-forming fluid features.Laser Raman analysis indicates that the ore-forming fluids is a H_(2)O-NaCl-CH_(4)(-CO_(2))system.Fluid inclusions microthermometry shows a homogenization temperature of 181-375°C and a salinity of 5.26%-16.99%for the disseminated-banded Cu-Zn mineralization;but a homogenization temperature of 142-343°C and a salinity of 5.41%-21.19%for the massive-veined Cu-Zn mineralization.These features suggest a medium-high temperature and a medium salinity for the ore-forming fluids.H-O isotopic data indicates that the ore-forming fluids were mainly from the metamorphic and magmatic water,plus minor formation water.And sulfur isotopic data indicates that sulfur was mainly derived from the formation and magmatic rocks.Metallogenesis of the disseminated-banded mineralization was mainly correlated with fluid mixing and water-rock reaction;whereas that of the massive-veined mineralization was mainly correlated with fluid boiling.The genetic type of the deposit is a medium-high temperature hydrothermal deposit related to magmatism and controlled by shear zones.This study is beneficial to understand the stratiform copper deposit.
基金financially supported by the National Natural Science Foundation of China (No. 51804279)
文摘Al_2O_3 and TiN inclusions in interstitial-free(IF) steel deteriorate the properties of the steel. To decrease the defects of cold-rolled sheet, it is important to clearly distinguish between the degrees of damage caused by these two inclusions on the surface quality of the steel. In this study, a nanoindenter was used to test the mechanical properties of the inclusions, and the distribution and size of the inclusions were obtained by scanning electron microscopy(SEM). It was found that when only mechanical properties are considered, TiN inclusions are more likely to cause defects than Al_2O_3 inclusions of the same size during the rolling process. However, Al_2O_3 inclusions are generally more inclined to cause defects in the rolling process than TiN inclusions because of their distribution characteristic in the thickness direction. The precipitation of Al_2O_3 and TiN was obtained through thermodynamical calculations. The growth laws of inclusions at different cooling rates were calculated by solidification and segregation models. The results show that the precipitation regularity is closely related to the distribution law of the inclusions in IF slabs along the thickness direction.
基金financially supported by the Key Technology Development of Bearing Steel for Major Equipment (No.2012AA03A503)
文摘The Al_2O_3, MnS, and TiN inclusions in bearing steel will deteriorate the steel's mechanical properties. Therefore, elucidating detailed characteristics of these inclusions in consumable electrode during the electroslag remelting process is important for achieving a subsequently clean ingot. In this study, a confocal scanning violet laser microscope was used to simulate the remelting process and observe, in real time, the behaviors of inclusions. The obtained images show that, after the temperature exceeded the steel solidus temperature, MnS and TiN inclusions in the specimen began to dissolve. Higher temperatures led to faster dissolution, and the inclusions disappeared before the steel was fully liquid. In the case of an observed Al_2O_3 inclusion, its shape changed from angular to a smooth ellipsoid in the region where the solid and liquid coexisted and it began to dissolve as the temperature continued to increase. This dissolution was driven by the difference in oxygen potential between the inclusion and the liquid steel.
基金financially supported by the Fundamental Research Funds for the Central Universities (No. FRF-TP-16-079A1)the National Science Foundation for Young Scientists of China (No. 51704021)+1 种基金the Joint Funds of National Natural Science Foundation of China (No. U1560203)supported by Beijing Key Laboratory of Special Melting and Preparation of High-end Metal Materials
文摘Many researchers have explored the inclusion modification mechanism to improve non-metallic inclusion modifications in steelmaking. In this study, two types of industrial trials on inclusion modifications in liquid steel were conducted using ultra-low-carbon Al-killed steel with different Mg and Ca contents to verify the effects of Ca and Mg contents on the modification mechanism of Al_2O_3-based inclusions during secondary refining. The results showed that Al_2O_3-based inclusions can be modified into liquid calcium aluminate or a multi-component inclusion with the addition of a suitable amount of Ca. In addition, [Mg] in liquid steel can further reduce CaO in liquid calcium aluminate to drive its evolution into CaO–MgO–Al_2O_3 multi-component inclusions. Thermodynamic analysis confirmed that the reaction between [Mg] and CaO in liquid calcium aluminate occurs when the MgO content of liquid calcium aluminate is less than 3 wt% and the temperature is higher than 1843 K.
基金financially supported by the National Natural Science Foundation of China (No. 51574026)
文摘Industrial experiments were carried out to investigate the formation of CaS-bearing inclusion during Ca double modification in oil casting steels using polished cross sections and electrolytic extraction. Immediately after Ca addition, the role of newly generated CaS as an intermediate reaction product, which modified the Al_2O_3 inclusion into a liquid calcium aluminate, was confirmed. The formation of transient CaS was attributed to the high surface segregation of S at the liquid steel-calcium vapor interface, where a simple site coverage model based upon the Langmuir adsorption equation was established. Moreover, a CaS outer layer surrounding the liquid calcium aluminate was attained mainly in the tundish, which was distributed unevenly on the surface of liquid particles according to the three-dimensional mapping results. The surface of a well-modified calcium aluminate with higher CaO activity and Al_2O_3 activity under bulk composition conditions in the tundish acted as a favorable site for the generation of CaS. Additionally, CaS could be precipitated directly onto existing inclusions during solidification of the steel, which led to various morphologies of CaS-bearing inclusions in slabs. Furthermore, the phase transformation of inclusions during solidification was strongly influenced both by the S content and the Ca/S ratio in the tundish via thermodynamics.
基金financially supported by the National Natural Science Foundation of China (No. 51674069)the National Key R & D Program of China (No. 2017YFC0805100)
文摘For the control of surface defects in interstitial-free(IF) steel, quantitative metallographic analyses of near-surface inclusions and surface liquid flow detection via the nail-board tipping method were conducted. The results show that, at casting speeds of 0.8 and 1.0 m/min, a thin liquid mold flux layer forms and non-uniform floating of argon bubbles occurs, inducing the entrainment and subsequent entrapment of the liquid flux; fine inclusion particles of Al_2O_3 can also aggregate at the solidification front. At higher casting speeds of 1.4 and 1.6 m/min, the liquid mold flux can be entrained and carried deeper into the liquid steel pool because of strong level fluctuations of the liquid steel and the flux. The optimal casting speed is approximately 1.2 m/min, with the most favorable surface flow status and, correspondingly, the lowest number of inclusions near the slab surface.
基金financially supported by the National Key Research and Development Program of China(2016YFB0301200)
文摘This paper summarizes melting methods of titanium and titanium alloy, such as vacuum arc melting(VAR) and electron beam cold hearth melting(EBCHM), and the related inclusions formed when using these melting methods. Low-density inclusions are resulted from contamination of air, and high-density inclusions are caused by refractory elements. The formation process of inclusions was analysed. The removal mechanism of different kinds of inclusions was specified. Low-density inclusions are removed mainly by resolving. This is a comprehensive process containing reaction diffusion. The resolving rate of high-density inclusions is so low that these inclusions are mainly removed by sedimentation. The experiments and physical models of inclusions are detailed. In various melting methods, vacuum arc melting is prominent. However, this method cannot remove inclusions effectively, which usually results in repeat melting. Electron beam cold hearth melting has the best ability of removing inclusions. These results can provide instructions to researchers of titanium and titanium alloys.
基金financially supported by Xining Special Steel Plant and the National Natural Science Foundation of China (No. 51674024)
文摘Industrial experiments with three types of slags were performed to investigate the effect of slag on oxide inclusions during electroslag remelting(ESR) process. G20CrNi2Mo bearing steel was used as the consumable electrode and remelted using a 2400-kg industrial furnace. The results showed that most inclusions in the electrode were low-melting-point CaO-MgO-Al_2O_3. After ESR, all the inclusions in ingots were located outside the liquid region. When the slag consisted of 65.70 wt% CaF_2, 28.58 wt% Al_2O_3, and 4.42 wt% CaO was used, pure Al_2O_3 were the dominant inclusions in ingot, some of which presented a clear trend of agglomeration. When the ingot was remelted by a multi-component slag with 16.83 wt% CaO, a certain amount of sphere CaAl_4O_7 inclusions larger than 5 μm were generated in ingot. The slag with 8.18 wt% CaO exhibited greater capacity to control the inclusion characteristics. Thermodynamic calculations indicated that the total Ca and Mg in ingots were attributed from the relics in electrode and strongly influenced by the slag composition. The formation of ingot inclusions was calculated by FactSage^(TM) 7.0, and the results were basically in accordance with the observed inclusions, indicating that a quasi-thermodynamic equilibrium could be obtained in the metal pool.
文摘As the substrate for nucleation of primary austenite in hardfacing metals, the effectiveness of RE inclusions and the most common inclusions such as Al2O3, SiO2 and MnO in hardfacing metals of medium-high carbon steelswas analyzed and calculated in detail. The calculation based on the theory of planar lattice misfit shows that Ce2O3,La2O3 and Ce2O2S, instead of SiO2, Al2O3, MnO and CeS, are effective as the heterogeneous nuclei of primary austenitein medium-high carbon steels.
基金Project supported by the Natural Science Foundation of Henan Province,China(Grant No.182300410279)the Key Science and Technology Research Project of Henan Province,China(Grant No.182102210311)+2 种基金the Key Scientific Research Project in Colleges and Universities of Henan Province,China(Grant No.18A430017)the Professional Practice Demonstration Base Program for Professional Degree Graduate in Material Engineering of Henan Polytechnic University,China(Grant No.2016YJD03)the Fund for the Innovative Research Team(in Science and Technology)in the University of Henan Province,China(Grant No.19IRTSTHN027)
文摘The inclusions in large diamond single crystals have effects on its ultimate performance, which restricts its industrial applications to a great extent. Therefore, it is necessary to study the inclusions systematically. In this paper, large diamond single crystals with different content values of inclusions are synthesized along the(100) surface by the temperature gradient method(TGM) under 5.6 GPa at different temperatures. With the synthetic temperature changing from 1200?C to 1270?C,the shapes of diamonds change from plate to low tower, to high tower, even to steeple. From the microscopic photographs of the diamond samples, it can be observed that with the shapes of the samples changing at different temperatures, the content values of inclusions in diamonds become zero, a little, much and most, correspondingly. Consequently, with the temperature growing from low to high, the content values of inclusions in crystals increase. The origin of inclusions is explained by the difference in growth rate between diamond crystal and its surface. The content values of inclusions in diamond samples are quantitatively calculated by testing the densities of diamond samples. And the composition and inclusion content are analyzed by energy dispersive spectroscopy(EDS) and x-ray diffraction(XRD). From contrasting scanning electron microscopy(SEM) photographs, it can be found that the more the inclusions in diamond, the more imperfect the diamond surface is.
