In this study,the microstructure and mechanical properties of a multi-layered 316L-TiC composite material produced by selective laser melting(SLM)additive manufacturing process are investigated.Three different layers,...In this study,the microstructure and mechanical properties of a multi-layered 316L-TiC composite material produced by selective laser melting(SLM)additive manufacturing process are investigated.Three different layers,consisting of 316L stainless steel,316L-5 wt%TiC and 316L-10 wt%TiC,were additively manufactured.The microstructure of these layers was characterized by optical microscopy(OM)and scanning electron microscopy(SEM).X-ray diffraction(XRD)was used for phase analysis,and the mechanical properties were evaluated by tensile and nanoindentation tests.The microstructural observations show epitaxial grain growth within the composite layers,with the elongated grains growing predominantly in the build direction.XRD analysis confirms the successful incorporation of the TiC particles into the 316L matrix,with no unwanted phases present.Nanoindentation results indicate a significant increase in the hardness and modulus of elasticity of the composite layers compared to pure 316L stainless steel,suggesting improved mechanical properties.Tensile tests show remarkable strength values for the 316L-TiC composite samples,which can be attributed to the embedded TiC particles.These results highlight the potential of SLM in the production of multi-layer metal-ceramic composites for applications that require high strength and ductility of metallic components in addition to the exceptional hardness of the ceramic particles.展开更多
The use of a constrained groove pressing(CGP) method to plastically deform AA6063 aluminum alloy led to the improved surface properties. It was found that hardness magnitude is dramatically improved and its uniformity...The use of a constrained groove pressing(CGP) method to plastically deform AA6063 aluminum alloy led to the improved surface properties. It was found that hardness magnitude is dramatically improved and its uniformity is considerably decreased after the first pass, while subsequent passes result in better hardness behavior for the processed material. Also, the elongated grains formed in the first pass of the CGP are gradually converted to the equiaxed counterparts by adding pass numbers. Eventually, higher corrosion resistance of the sample by imposing the CGP process is related to the quick formation of passivation film and the change in the morphology of the second phase and precipitates which hinder their electrochemical reactions and decrease the potential localized attack sites.展开更多
The need for light and high specific strength materials in many fields such as automotive and aerospace is increasing day by day.Magnesium(Mg)-based materials have become attractive for many industries thanks to their...The need for light and high specific strength materials in many fields such as automotive and aerospace is increasing day by day.Magnesium(Mg)-based materials have become attractive for many industries thanks to their high specific strength, good vibration damping ability, and recyclability. However, Mg’s low strength and wear resistance are important barriers limiting its industrial use. Researchers are developing Mg matrix composites using various reinforcements and expanding the use of Mg-based materials. The conventional reinforcements are Al2O3, SiC, B4C, TiB2, CNT, and GNPs for the production of Mg matrix composites. Researchers have been trying to reduce the cost of Mg matrix composites in recent years by using cheaper and environmentally friendly reinforcements. These reinforcements are solid wastes such as eggshell, fly ash, red mud, and waste glass, and their use in composite systems is becoming more common day by day. This review focuses on the Mg matrix composites reinforced with solid waste particles and the changes in wear, mechanical, corrosion, and thermal properties with the addition of these reinforcements.展开更多
7039 Al alloy plates which were used as armor materials were produced by powder metallurgy method. The prepared mixed powders were pressed and plated by extrusion process. These plates, after being subjected to T6 hea...7039 Al alloy plates which were used as armor materials were produced by powder metallurgy method. The prepared mixed powders were pressed and plated by extrusion process. These plates, after being subjected to T6 heat treatment, were joined double-sided by friction stir welding method. Microstructure and microhardness of the welded plate were investigated. It was determined that the finest grain structure and the lowest hardness value occurred in the stir zone as 2-6 mm and HV 80.9, respectively. In order to determine the ballistic properties of welded plates, 7.62 mm armor piercing projectiles were shot to the base metal（BM）, heat affected zone（HAZ）, and thermomechanically affected zone＋stir zone（TMAZ＋SZ）. Ballistic limits（v_（50）） of these zones were determined. The ballistic limits of the BM, TMAZ＋SZ, and HAZ of the plate were approximately 14.7%, 15.3%, and 17.9% lower than that of the standard plate at the same thickness, respectively. It was determined that the armor piercing projectiles created petaling and ductile hole enlargement failure types at the armor plate. Ballistic and mechanical results can be enhanced by hot-cold rolling mills after extrusion and particle reinforcement.展开更多
The study was aimed to identify the problems and also to suggest some solutions for robotic systems applications in harvesting of kiwi and apples. The results obtained show that physicomechanical properties of the har...The study was aimed to identify the problems and also to suggest some solutions for robotic systems applications in harvesting of kiwi and apples. The results obtained show that physicomechanical properties of the harvested fruits had an effect on the use of robotic systems. Parameters such as weight, height, width, thickness and surface area were identified as the main effect in robotic fruit harvesting. Image processing techniques also had direct effect on robotic systems operation which therefore requires careful selection procedure to achieve results accuracy. It was observed that the C# programming language used in robotic systems fruit harvesting should be parallel with the image processing to ensure accurate conversion of kinematic calculation, system input parameters and constant values. The use of hobby-type parts of a robot in the prototype study showed reliable results. However, to ensure functionality of the robotic systems application, industrial robots and servo engines should be used. It was also observed that the use of a gripper for picking the fruits from the branch must The engines that make the system work should be strong and the be made considering the physicomechanical properties of the fruit. cutting system should also be appropriate.展开更多
In this study, two Satureja L. species from different localities of Turkey （Satureja hortensis L. and Satureja boissieri Hausskn. ex Boiss.） have been studied to determine their taxonomic classification based on che...In this study, two Satureja L. species from different localities of Turkey （Satureja hortensis L. and Satureja boissieri Hausskn. ex Boiss.） have been studied to determine their taxonomic classification based on chemical characters. For this purpose, aerial parts of the studied taxa were investigated by HS-SPME/GC-MS. 28, 30 and 29 compounds were identified in S. boissieri from Sanhurfa, BingS1 and Malatya accounting from 90.80%, 91.31% and 92.67% of the whole oil, respectively. 26, 30 and 28 compounds were identified in S. hortensis from Adlyaman, Diyarbaklr, Elazl~ accounting from 93.20%, 92.85% and 92.42% of the whole oil, respectively, y-terpinene （30.4%, 26.5% and 32.1%）, carvacrol （26.4%, 25.2% and 23.3%） and p-cymene （10.5%, 13.2% and 10.4%） were determined as main compounds of S. boissieri in Sanhurfa, Bing6l and Malatya species, respectively. Carvacrol （25.0%, 34.1% and 32.1%）, thymol （28.2%, 20.2% and 28.1%） and y-terpinene （10.1%, 11.3% and 9.4%） were found as main constituents of S. hortensis in Adlyaman, Diyarbaklr and Elazl~ samples, respectively. The chemical distributions of the essential oil compounds in the Satureja pattern were discussed in respect to their chemotaxonomy and natural products.展开更多
The polymethyl-methacrylate (PMMA)-based composites were prepared using goose feather fibers at different diameters. The fibers, which were washed and dried, cut through the shaft, and their sizes were shrunk to short...The polymethyl-methacrylate (PMMA)-based composites were prepared using goose feather fibers at different diameters. The fibers, which were washed and dried, cut through the shaft, and their sizes were shrunk to short fiber form. Then the obtained short fibers were added into acryl matrix in portions of 2%, 4%, 6%, and 8% in volume. The mixture containing goose feather fiber was shaped via free casting method, and the goose feather fiber/PMMA composites were obtained. The samples, which were processed in accordance with the standards of test to be implemented after the thermal curing process, were characterized in terms of the mechanical properties after being evaluated by using three-point flexure test and impact test. For the goose feather-added composites, a significant increase was observed in rupture resistance, flexural strength, and flexure module. The flexure test curves of composites clearly revealed the slow and stable crack enlargement. Micro mechanisms of toughening and rupture processes were observed under the light of microstructure of rupture surfaces. The results of present study showed that the goose feather can be used as an important reinforcing material for bio-composites.展开更多
Today, remote sensing is used for different methods and different purposes. In all of the detection methods, some considerations such as low energy consumption, low cost, insensitivity to environmental changes, high a...Today, remote sensing is used for different methods and different purposes. In all of the detection methods, some considerations such as low energy consumption, low cost, insensitivity to environmental changes, high accuracy, high reliability and robustness become important. Taking into account these facts, remote sensing methods are used in applications such as geological and archeological research, engineering areas, health services, preserving and controlling natural life, determination of underground sources, controlling air, sea and road traffic, military applications, etc. The method to be used is based on the object type to be detected, material to be made, and location to be found. The remote sensing methods from the past up to today can be listed as acoustic and seismic, ground penetration radar (GPR) detection, electromagnetic induction, infrared (IR) imaging, neutron quadrupole resonance (NQR), thermal neutron activation (TNA), neutron back scattering, X-ray back scattering, and magnetic anomaly detection. In these methods, detected raw images have to be processed, filtered and enhanced. In order to achieve these operations, some algorithms are needed to be developed. In this study, the methods used in detecting land mines remotely and their performance analysis have been given. In this way, the last situation on the advantages and disadvantages of methods used, application areas and detection accuracies are determined. Furthermore, the algorithms such as transmission line matrix (TLM), finite difference time-domain (FDTD), the method of moment (MoM), split step parabolic equation (SSPE) and image processing and intelligent algorithms are presented in detail.展开更多
Turkey is located in the Alpine-Himalayan seismic zone.The Anatolian plate has witnessed very severe and destructive earthquakes both in the past and today.In this study,statistical analyses of earthquakes that occurr...Turkey is located in the Alpine-Himalayan seismic zone.The Anatolian plate has witnessed very severe and destructive earthquakes both in the past and today.In this study,statistical analyses of earthquakes that occurred between 1914 and 2019 along the Fethiye-Burdur fault zone,which is an active line,were conducted using geographic information systems.Analyses of standard distance,standard deviational eclipse,mean center,and median center were conducted to determine the geographic distributions of epicenters with a magnitude value of 3.5 and above.Quadrat and Average Nearest Neighbor analyses were used to reveal the spatial pattern.Anselin Local Moran I and Getis Ord Gi*method were used to determining where the earthquake epicenters are clustered locally.Kernel Density analyses were conducted to measure earthquake epicenters’density.Quadrat analysis,Average Nearest Neighbor,Global Moran’s I,and Getis-Ord General G indices demonstrated that earthquakes are clustered in certain regions and are related to each other positionally.Anselin Moran’s I regional analyses revealed that high values were clustered in the West of Burdur city center and the district of Yeşilova,and similar results were obtained in the Getis Ord Gi*method.展开更多
文摘In this study,the microstructure and mechanical properties of a multi-layered 316L-TiC composite material produced by selective laser melting(SLM)additive manufacturing process are investigated.Three different layers,consisting of 316L stainless steel,316L-5 wt%TiC and 316L-10 wt%TiC,were additively manufactured.The microstructure of these layers was characterized by optical microscopy(OM)and scanning electron microscopy(SEM).X-ray diffraction(XRD)was used for phase analysis,and the mechanical properties were evaluated by tensile and nanoindentation tests.The microstructural observations show epitaxial grain growth within the composite layers,with the elongated grains growing predominantly in the build direction.XRD analysis confirms the successful incorporation of the TiC particles into the 316L matrix,with no unwanted phases present.Nanoindentation results indicate a significant increase in the hardness and modulus of elasticity of the composite layers compared to pure 316L stainless steel,suggesting improved mechanical properties.Tensile tests show remarkable strength values for the 316L-TiC composite samples,which can be attributed to the embedded TiC particles.These results highlight the potential of SLM in the production of multi-layer metal-ceramic composites for applications that require high strength and ductility of metallic components in addition to the exceptional hardness of the ceramic particles.
基金funded by“Quality Engineering Project of Anhui Province of China in 2016”entitled mold design and manufacturing experimental training center(2016sxzx050)。
文摘The use of a constrained groove pressing(CGP) method to plastically deform AA6063 aluminum alloy led to the improved surface properties. It was found that hardness magnitude is dramatically improved and its uniformity is considerably decreased after the first pass, while subsequent passes result in better hardness behavior for the processed material. Also, the elongated grains formed in the first pass of the CGP are gradually converted to the equiaxed counterparts by adding pass numbers. Eventually, higher corrosion resistance of the sample by imposing the CGP process is related to the quick formation of passivation film and the change in the morphology of the second phase and precipitates which hinder their electrochemical reactions and decrease the potential localized attack sites.
文摘The need for light and high specific strength materials in many fields such as automotive and aerospace is increasing day by day.Magnesium(Mg)-based materials have become attractive for many industries thanks to their high specific strength, good vibration damping ability, and recyclability. However, Mg’s low strength and wear resistance are important barriers limiting its industrial use. Researchers are developing Mg matrix composites using various reinforcements and expanding the use of Mg-based materials. The conventional reinforcements are Al2O3, SiC, B4C, TiB2, CNT, and GNPs for the production of Mg matrix composites. Researchers have been trying to reduce the cost of Mg matrix composites in recent years by using cheaper and environmentally friendly reinforcements. These reinforcements are solid wastes such as eggshell, fly ash, red mud, and waste glass, and their use in composite systems is becoming more common day by day. This review focuses on the Mg matrix composites reinforced with solid waste particles and the changes in wear, mechanical, corrosion, and thermal properties with the addition of these reinforcements.
文摘7039 Al alloy plates which were used as armor materials were produced by powder metallurgy method. The prepared mixed powders were pressed and plated by extrusion process. These plates, after being subjected to T6 heat treatment, were joined double-sided by friction stir welding method. Microstructure and microhardness of the welded plate were investigated. It was determined that the finest grain structure and the lowest hardness value occurred in the stir zone as 2-6 mm and HV 80.9, respectively. In order to determine the ballistic properties of welded plates, 7.62 mm armor piercing projectiles were shot to the base metal（BM）, heat affected zone（HAZ）, and thermomechanically affected zone＋stir zone（TMAZ＋SZ）. Ballistic limits（v_（50）） of these zones were determined. The ballistic limits of the BM, TMAZ＋SZ, and HAZ of the plate were approximately 14.7%, 15.3%, and 17.9% lower than that of the standard plate at the same thickness, respectively. It was determined that the armor piercing projectiles created petaling and ductile hole enlargement failure types at the armor plate. Ballistic and mechanical results can be enhanced by hot-cold rolling mills after extrusion and particle reinforcement.
文摘The study was aimed to identify the problems and also to suggest some solutions for robotic systems applications in harvesting of kiwi and apples. The results obtained show that physicomechanical properties of the harvested fruits had an effect on the use of robotic systems. Parameters such as weight, height, width, thickness and surface area were identified as the main effect in robotic fruit harvesting. Image processing techniques also had direct effect on robotic systems operation which therefore requires careful selection procedure to achieve results accuracy. It was observed that the C# programming language used in robotic systems fruit harvesting should be parallel with the image processing to ensure accurate conversion of kinematic calculation, system input parameters and constant values. The use of hobby-type parts of a robot in the prototype study showed reliable results. However, to ensure functionality of the robotic systems application, industrial robots and servo engines should be used. It was also observed that the use of a gripper for picking the fruits from the branch must The engines that make the system work should be strong and the be made considering the physicomechanical properties of the fruit. cutting system should also be appropriate.
文摘In this study, two Satureja L. species from different localities of Turkey （Satureja hortensis L. and Satureja boissieri Hausskn. ex Boiss.） have been studied to determine their taxonomic classification based on chemical characters. For this purpose, aerial parts of the studied taxa were investigated by HS-SPME/GC-MS. 28, 30 and 29 compounds were identified in S. boissieri from Sanhurfa, BingS1 and Malatya accounting from 90.80%, 91.31% and 92.67% of the whole oil, respectively. 26, 30 and 28 compounds were identified in S. hortensis from Adlyaman, Diyarbaklr, Elazl~ accounting from 93.20%, 92.85% and 92.42% of the whole oil, respectively, y-terpinene （30.4%, 26.5% and 32.1%）, carvacrol （26.4%, 25.2% and 23.3%） and p-cymene （10.5%, 13.2% and 10.4%） were determined as main compounds of S. boissieri in Sanhurfa, Bing6l and Malatya species, respectively. Carvacrol （25.0%, 34.1% and 32.1%）, thymol （28.2%, 20.2% and 28.1%） and y-terpinene （10.1%, 11.3% and 9.4%） were found as main constituents of S. hortensis in Adlyaman, Diyarbaklr and Elazl~ samples, respectively. The chemical distributions of the essential oil compounds in the Satureja pattern were discussed in respect to their chemotaxonomy and natural products.
文摘The polymethyl-methacrylate (PMMA)-based composites were prepared using goose feather fibers at different diameters. The fibers, which were washed and dried, cut through the shaft, and their sizes were shrunk to short fiber form. Then the obtained short fibers were added into acryl matrix in portions of 2%, 4%, 6%, and 8% in volume. The mixture containing goose feather fiber was shaped via free casting method, and the goose feather fiber/PMMA composites were obtained. The samples, which were processed in accordance with the standards of test to be implemented after the thermal curing process, were characterized in terms of the mechanical properties after being evaluated by using three-point flexure test and impact test. For the goose feather-added composites, a significant increase was observed in rupture resistance, flexural strength, and flexure module. The flexure test curves of composites clearly revealed the slow and stable crack enlargement. Micro mechanisms of toughening and rupture processes were observed under the light of microstructure of rupture surfaces. The results of present study showed that the goose feather can be used as an important reinforcing material for bio-composites.
文摘Today, remote sensing is used for different methods and different purposes. In all of the detection methods, some considerations such as low energy consumption, low cost, insensitivity to environmental changes, high accuracy, high reliability and robustness become important. Taking into account these facts, remote sensing methods are used in applications such as geological and archeological research, engineering areas, health services, preserving and controlling natural life, determination of underground sources, controlling air, sea and road traffic, military applications, etc. The method to be used is based on the object type to be detected, material to be made, and location to be found. The remote sensing methods from the past up to today can be listed as acoustic and seismic, ground penetration radar (GPR) detection, electromagnetic induction, infrared (IR) imaging, neutron quadrupole resonance (NQR), thermal neutron activation (TNA), neutron back scattering, X-ray back scattering, and magnetic anomaly detection. In these methods, detected raw images have to be processed, filtered and enhanced. In order to achieve these operations, some algorithms are needed to be developed. In this study, the methods used in detecting land mines remotely and their performance analysis have been given. In this way, the last situation on the advantages and disadvantages of methods used, application areas and detection accuracies are determined. Furthermore, the algorithms such as transmission line matrix (TLM), finite difference time-domain (FDTD), the method of moment (MoM), split step parabolic equation (SSPE) and image processing and intelligent algorithms are presented in detail.
文摘Turkey is located in the Alpine-Himalayan seismic zone.The Anatolian plate has witnessed very severe and destructive earthquakes both in the past and today.In this study,statistical analyses of earthquakes that occurred between 1914 and 2019 along the Fethiye-Burdur fault zone,which is an active line,were conducted using geographic information systems.Analyses of standard distance,standard deviational eclipse,mean center,and median center were conducted to determine the geographic distributions of epicenters with a magnitude value of 3.5 and above.Quadrat and Average Nearest Neighbor analyses were used to reveal the spatial pattern.Anselin Local Moran I and Getis Ord Gi*method were used to determining where the earthquake epicenters are clustered locally.Kernel Density analyses were conducted to measure earthquake epicenters’density.Quadrat analysis,Average Nearest Neighbor,Global Moran’s I,and Getis-Ord General G indices demonstrated that earthquakes are clustered in certain regions and are related to each other positionally.Anselin Moran’s I regional analyses revealed that high values were clustered in the West of Burdur city center and the district of Yeşilova,and similar results were obtained in the Getis Ord Gi*method.
