Additive manufacturing technology is highly regarded due to its advantages,such as high precision and the ability to address complex geometric challenges.However,the development of additive manufacturing process is co...Additive manufacturing technology is highly regarded due to its advantages,such as high precision and the ability to address complex geometric challenges.However,the development of additive manufacturing process is constrained by issues like unclear fundamental principles,complex experimental cycles,and high costs.Machine learning,as a novel artificial intelligence technology,has the potential to deeply engage in the development of additive manufacturing process,assisting engineers in learning and developing new techniques.This paper provides a comprehensive overview of the research and applications of machine learning in the field of additive manufacturing,particularly in model design and process development.Firstly,it introduces the background and significance of machine learning-assisted design in additive manufacturing process.It then further delves into the application of machine learning in additive manufacturing,focusing on model design and process guidance.Finally,it concludes by summarizing and forecasting the development trends of machine learning technology in the field of additive manufacturing.展开更多
Magnesium(Mg) and its alloys have been intensively studied to develop the next generation of bone implants recently, but their clinical application is restricted by rapid degradation and unsatisfied osteogenic effect ...Magnesium(Mg) and its alloys have been intensively studied to develop the next generation of bone implants recently, but their clinical application is restricted by rapid degradation and unsatisfied osteogenic effect in vivo. A bioactive chemical conversion Mg-phenolic networks complex coating(e EGCG) was stepwise incorporated by epigallocatechin-3-gallate(EGCG) and exogenous Mg^(2+)on Mg-2Zn magnesium alloy. Simplex EGCG induced chemical conversion coating(c EGCG) was set as compare group. The in vitro corrosion behavior of Mg-2Zn alloy, c EGCG and e EGCG was evaluated in SBF using electrochemical(PDP, EIS) and immersion test. The cytocompatibility was investigated with rat bone marrow mesenchymal stem cells(r BMSCs). Furthermore, the in vivo tests using a rabbit model involved micro computed tomography(Micro-CT) analysis, histological observation, and interface analysis. The results showed that the e EGCG is Mgphenolic multilayer coating incorporated Mg-phenolic networks, which is rougher, more compact and much thicker than c EGCG. The e EGCG highly improved the corrosion resistance of Mg-2Zn alloy, combined with its lower average hemolytic ratios, continuous high scavenging effect ability and relatively moderate contact angle features, resulting in a stable and suitable biological environment, obviously promoted r BMSCs adhesion and proliferation. More importantly, Micro-CT, histological and interface elements distribution evaluations all revealed that the e EGCG effectively inhibited degradation and enhanced bone tissue formation of Mg alloy implants. This study puts forward a promising bioactive chemical conversion coating with Mg-phenolic networks for the application of biodegradable orthopedic implants.展开更多
Attaining a highly efficient and inexpensive electrocatalyst is significant for the hydrogen evolution reaction(HER)but still challenging nowadays.The transition-metal phosphides(TMPs)catalysts with platinum-like elec...Attaining a highly efficient and inexpensive electrocatalyst is significant for the hydrogen evolution reaction(HER)but still challenging nowadays.The transition-metal phosphides(TMPs)catalysts with platinum-like electronic structures are a potential candidate for the HER,but those are prone to be strongly bound with hydrogen intermediates(H∗),resulting in sluggish HER kinetics.Herein we report a unique hybrid structure of CoP anchored on graphene nanoscrolls@carbon nano tubes(CNTs)scaffold(Ni M@C-CoP)encapsulating various Ni M(M=Zn,Mo,Ni,Co)bimetal nanoalloy via chemical vapor deposi-tion(CVD)growth of CNT on graphene nanoscrolls followed by the impregnation of cobalt precursors and phosphorization for efficiently electrocatalytic hydrogen evolution.CoP nanoparticles mainly scattered at the tip of CNT branches which exhibited the analogical“Three-layer core-shell”structures.Experiments and density functional theory(DFT)calculations consistently disclose that the encapsulated various NiMs can offer different numbers of electrons to weaken the interactions of outmost CoP with H∗and push the downshift of the d-band center to different degrees as well as stabilize the outmost CoP nanopar-ticles to gain catalytic stability via the electron traversing effect.The electrocatalytic HER activity can be maximumly enhanced with low overpotentials of 78 mV(alkaline)and 89 mV(acidic)at a current density of 10 mA/cm^(2) and sustained at least 24 h especially for NiZn@C-CoP catalyst.This novel system is distinct from conventional three-layer heterostructure,providing a specially thought of d-band center control engineering strategy for the design of heterogeneous catalysts and expanding to other electrocat-alysts,energy storage,sensing,and other applications.展开更多
Endowing implant surfaces with combined antibacterial and osteogenic properties by drug-loaded coatings has made great strides,but how to achieve the combined excellence of infection-triggered bactericidal and in vivo...Endowing implant surfaces with combined antibacterial and osteogenic properties by drug-loaded coatings has made great strides,but how to achieve the combined excellence of infection-triggered bactericidal and in vivo-proven osteogenic activities without causing bacterial resistance still remains a formidable challenge.Herein,antimicrobial peptides(AMPs)with osteogenic fragments were designed and complexed on the surface of silver nanoparticle(AgNP)through hydrogen bonding,and the collagen structure-bionic silk fibroin(SF)was applied to carry AgNPs@AMPs to achieve infection-triggered antibacterial and osteointegration.As verified by TEM,AMPs contributed to the dispersion and size-regulation of AgNPs,with a particle size of about 20 nm,and a clear protein corona structure was observed on the particle surface.The release curve of silver ion displayed that the SF-based coating owned sensitive pH-responsive properties.In the antibacterial test against S.aureus for up to 21 days,the antibacterial rate had always remained above 99%.Meanwhile,the underlying mechanism was revealed,originating from the destruction of the bacterial cell membranes and ROS generation.The SF-based coating was conducive to the adhesion,diffusion,and proliferation of bone marrow stem cells(BMSCs)on the surface,and promoted the expression of osteogenic genes and collagen secretion.The in vivo implantation results showed that compared with the untreated Ti implants,SF-based coating enhanced osseointegration at week 4 and 8.Overall,the AgNPs@AMPs-loaded SF-based coating presented the ability to synergistically inhibit bacteria and promote osseointegration,possessing tremendous potential application prospects in bone defects and related-infection treatments.展开更多
In recent years, zinc based alloys as a new biodegradable metal material aroused intensive interests.However, the processing of Zn alloys micro-tubes(named slender-diameter and thin-walled tubes) is very difficult due...In recent years, zinc based alloys as a new biodegradable metal material aroused intensive interests.However, the processing of Zn alloys micro-tubes(named slender-diameter and thin-walled tubes) is very difficult due to their HCP crystal structure and unfavorable mechanical properties. This study aimed to develop a novel technique to produce micro-tube of Zn alloy with good performance for biodegradable vascular stent application. In the present work, a processing method that combined drilling, cold rolling and optimized drawing was proposed to produce the novel Zn–5Mg–1Fe(wt%) alloy microtubes. The micro-tube with outer diameter of 2.5 mm and thickness of 130 μm was fabricated by this method and its dimension errors are within 10 μm. The micro-tube exhibits a fine and homogeneous microstructure, and the ultimate tensile strength and ductility are more than 220 MPa and 20% respectively. In addition, the micro-tube and stents of Zn alloy exhibit superior in vitro corrosion and expansion performance. It could be concluded that the novel Zn alloy micro-tube fabricated by above method might be a promising candidate material for biodegradable stent.展开更多
In this study, microstructural adjustments and mechanical properties of a cold-rolled nearβ-type alloy Ti-25Nb-3Zr-3Mo-2Sn (wt%) sheet were investigated.Microstructures and phase transformation products strongly depe...In this study, microstructural adjustments and mechanical properties of a cold-rolled nearβ-type alloy Ti-25Nb-3Zr-3Mo-2Sn (wt%) sheet were investigated.Microstructures and phase transformation products strongly depended on aging temperatures. Solution treatments within singleβ-phase field removed the stress-inducedα″martensites and produced a few new lath-shaped ones, but metastableβphase still dominated. This is exactly the reason why current alloy exhibits the lowest modulus (54 GPa) and best elongation to fracture (39%),but the worst yield strength of only 340 MPa, at solutiontreated state. A fairly large number of ellipsoidalωphase nanoparticles precipitated throughout parentβphase during aging at 380℃. Theseωnanoparticles possess remarkable strengthening effect, but deteriorate ductility seriously. A novel post-aging process was proposed to remove brittleωphase. By contrast, aging at 450℃resulted in sufficient precipitation of fine needle-like a phase. This brought about the best combination of high yield strength (770 MPa) and moderate elastic modulus(75 GPa) and good elongation (15%) for biomedical implants.展开更多
The gradient porous Ti3Zr2Sn3Mo25Nb(TLM)alloy rods were fabricated through sintering the alloyed powder to a solid core.The porous sample was then modified by a Micro Arc Oxidation(MAO)treatment in an electrolyte cont...The gradient porous Ti3Zr2Sn3Mo25Nb(TLM)alloy rods were fabricated through sintering the alloyed powder to a solid core.The porous sample was then modified by a Micro Arc Oxidation(MAO)treatment in an electrolyte containing calcium and phosphate,a hydrothermal treatment enabled secondary microporous hydroxyapatite(HA)coating,and a further bone morphogenetic protein-2(BMP-2)loading treatment through immersion and freeze-drying.The treatment led to an orderly secondary microporous coating containing HA nano-particles and evenly distributed BMP-2 in the porous coatings.As a result,osteoblasts could adhere and grow well on the coatings with a high cell adhesion rate and cell functional activity.The in-situ shear testing indicated that the interfacial strength had been enhanced significantly.Improvement of the bond formation and osseointegration with the titanium implant is attributed to increased surface area for the cell to attach,creating voids for the cell to grow in,and activating titanium surface by introducing bioactive ingredients such as HA and BMP-2.展开更多
Hydroxyapatite(HA)synthesized by a wet chemical route was subjected to heavy ion irradiation,using4 Me V Krypton ion(Kr17+)with ion fluence ranging from 1×1013 to 1×1015 ions/cm2.Glancing incidence X-ray dif...Hydroxyapatite(HA)synthesized by a wet chemical route was subjected to heavy ion irradiation,using4 Me V Krypton ion(Kr17+)with ion fluence ranging from 1×1013 to 1×1015 ions/cm2.Glancing incidence X-ray diffraction(GIXRD)results confirmed the phase purity of irradiated HA with a moderate contraction in lattice parameters,and further indicated the irradiation-induced structural disorder,evidenced by broadening of the diffraction peaks.High-resolution transmission electron microscopy(HRTEM)observations indicated that the applied Kr irradiation induced significant damage in the hydroxyapatite lattice.Specifically,cavities were observed with their diameter and density varying with the irradiation fluences,while a radiation-induced crystalline-to-amorphous transition with increasing ion dose was identified.Raman and X-ray photoelectron spectroscopy(XPS)analysis further indicated the presence of irradiationinduced defects.Ion release from pristine and irradiated materials following immersion in Tris(p H 7.4,37?)buffer showed that dissolution in vitro was enhanced by irradiation,reaching a peak at 0.1 dpa.We examined the effects of irradiation on the early stages of the mouse osteoblast-like cells(MC3 T3-E)response.A cell counting kit-8 assay(CCK-8 test)was carried out to investigate the cytotoxicity of samples,and viable cells can be observed on the irradiated materials.展开更多
This work investigates the strain rate dependence of dynamic recrystallization behaviour of high-purity zinc in room temperature compression under strain rates of 10^(-4)s^(-1),10-2s^(-1)and 0.5 s^(-1).Results from el...This work investigates the strain rate dependence of dynamic recrystallization behaviour of high-purity zinc in room temperature compression under strain rates of 10^(-4)s^(-1),10-2s^(-1)and 0.5 s^(-1).Results from electron backscatter diffraction provide insight into the deformation and dynamic recrystallization mechanisms operative.Continuous dynamic recrystallization,twin-induced dynamic recrystallization,and discontinuous dynamic recrystallization are all active under compressive deformation at room temperature.Due to the high stacking fault energy of Zn,continuous dynamic recrystallization is the dominant mechanism while discontinuous dynamic recrystallization only operates in the early stages of compression at 10^(-4)s^(-1).Dynamic recrystallization kinetics are enhanced at higher strain rates(10^(-2)s^(-1)and 0.5s^(-1))due to an increased contribution from twin-induced dynamic recrystallization.The present study reveals that the controlling mechanisms for continuous dynamic recrystallization are basalslip and 2ndorder pyramidalslip activity.Because the activation of slip systems is mainly determined by crystallographic orientation,continuous dynamic recrystallization behaviour varies with grain orientation according to their propensity for basal and 2ndorder pyramidal slip.展开更多
基金financially supported by the Technology Development Fund of China Academy of Machinery Science and Technology(No.170221ZY01)。
文摘Additive manufacturing technology is highly regarded due to its advantages,such as high precision and the ability to address complex geometric challenges.However,the development of additive manufacturing process is constrained by issues like unclear fundamental principles,complex experimental cycles,and high costs.Machine learning,as a novel artificial intelligence technology,has the potential to deeply engage in the development of additive manufacturing process,assisting engineers in learning and developing new techniques.This paper provides a comprehensive overview of the research and applications of machine learning in the field of additive manufacturing,particularly in model design and process development.Firstly,it introduces the background and significance of machine learning-assisted design in additive manufacturing process.It then further delves into the application of machine learning in additive manufacturing,focusing on model design and process guidance.Finally,it concludes by summarizing and forecasting the development trends of machine learning technology in the field of additive manufacturing.
基金supported by the Key Research and Development Program of Shaanxi Province (2019ZDLSF03-06) and (2020ZDLGY13-05)the National Key Research and Development Program of China (2020YFC1107202)。
文摘Magnesium(Mg) and its alloys have been intensively studied to develop the next generation of bone implants recently, but their clinical application is restricted by rapid degradation and unsatisfied osteogenic effect in vivo. A bioactive chemical conversion Mg-phenolic networks complex coating(e EGCG) was stepwise incorporated by epigallocatechin-3-gallate(EGCG) and exogenous Mg^(2+)on Mg-2Zn magnesium alloy. Simplex EGCG induced chemical conversion coating(c EGCG) was set as compare group. The in vitro corrosion behavior of Mg-2Zn alloy, c EGCG and e EGCG was evaluated in SBF using electrochemical(PDP, EIS) and immersion test. The cytocompatibility was investigated with rat bone marrow mesenchymal stem cells(r BMSCs). Furthermore, the in vivo tests using a rabbit model involved micro computed tomography(Micro-CT) analysis, histological observation, and interface analysis. The results showed that the e EGCG is Mgphenolic multilayer coating incorporated Mg-phenolic networks, which is rougher, more compact and much thicker than c EGCG. The e EGCG highly improved the corrosion resistance of Mg-2Zn alloy, combined with its lower average hemolytic ratios, continuous high scavenging effect ability and relatively moderate contact angle features, resulting in a stable and suitable biological environment, obviously promoted r BMSCs adhesion and proliferation. More importantly, Micro-CT, histological and interface elements distribution evaluations all revealed that the e EGCG effectively inhibited degradation and enhanced bone tissue formation of Mg alloy implants. This study puts forward a promising bioactive chemical conversion coating with Mg-phenolic networks for the application of biodegradable orthopedic implants.
基金This work was supported by the Science and Technology Pro-gram of Shaanxi Province(No.2019GY-200).Shengwu Guo and Wei Wang contributed to the material TEM and SEM characterizations in this work.
文摘Attaining a highly efficient and inexpensive electrocatalyst is significant for the hydrogen evolution reaction(HER)but still challenging nowadays.The transition-metal phosphides(TMPs)catalysts with platinum-like electronic structures are a potential candidate for the HER,but those are prone to be strongly bound with hydrogen intermediates(H∗),resulting in sluggish HER kinetics.Herein we report a unique hybrid structure of CoP anchored on graphene nanoscrolls@carbon nano tubes(CNTs)scaffold(Ni M@C-CoP)encapsulating various Ni M(M=Zn,Mo,Ni,Co)bimetal nanoalloy via chemical vapor deposi-tion(CVD)growth of CNT on graphene nanoscrolls followed by the impregnation of cobalt precursors and phosphorization for efficiently electrocatalytic hydrogen evolution.CoP nanoparticles mainly scattered at the tip of CNT branches which exhibited the analogical“Three-layer core-shell”structures.Experiments and density functional theory(DFT)calculations consistently disclose that the encapsulated various NiMs can offer different numbers of electrons to weaken the interactions of outmost CoP with H∗and push the downshift of the d-band center to different degrees as well as stabilize the outmost CoP nanopar-ticles to gain catalytic stability via the electron traversing effect.The electrocatalytic HER activity can be maximumly enhanced with low overpotentials of 78 mV(alkaline)and 89 mV(acidic)at a current density of 10 mA/cm^(2) and sustained at least 24 h especially for NiZn@C-CoP catalyst.This novel system is distinct from conventional three-layer heterostructure,providing a specially thought of d-band center control engineering strategy for the design of heterogeneous catalysts and expanding to other electrocat-alysts,energy storage,sensing,and other applications.
基金supported by the National Natural Science Foundation of China(Grant numbers 32071327,32101087)Shaanxi Science and Technology Association(2022JQ-312).
文摘Endowing implant surfaces with combined antibacterial and osteogenic properties by drug-loaded coatings has made great strides,but how to achieve the combined excellence of infection-triggered bactericidal and in vivo-proven osteogenic activities without causing bacterial resistance still remains a formidable challenge.Herein,antimicrobial peptides(AMPs)with osteogenic fragments were designed and complexed on the surface of silver nanoparticle(AgNP)through hydrogen bonding,and the collagen structure-bionic silk fibroin(SF)was applied to carry AgNPs@AMPs to achieve infection-triggered antibacterial and osteointegration.As verified by TEM,AMPs contributed to the dispersion and size-regulation of AgNPs,with a particle size of about 20 nm,and a clear protein corona structure was observed on the particle surface.The release curve of silver ion displayed that the SF-based coating owned sensitive pH-responsive properties.In the antibacterial test against S.aureus for up to 21 days,the antibacterial rate had always remained above 99%.Meanwhile,the underlying mechanism was revealed,originating from the destruction of the bacterial cell membranes and ROS generation.The SF-based coating was conducive to the adhesion,diffusion,and proliferation of bone marrow stem cells(BMSCs)on the surface,and promoted the expression of osteogenic genes and collagen secretion.The in vivo implantation results showed that compared with the untreated Ti implants,SF-based coating enhanced osseointegration at week 4 and 8.Overall,the AgNPs@AMPs-loaded SF-based coating presented the ability to synergistically inhibit bacteria and promote osseointegration,possessing tremendous potential application prospects in bone defects and related-infection treatments.
基金supported by the National Basic Research Program of China(973 Program)(Grant No.2012CB619102)the National Science Foundation of China(Grant No.31400821)the innovation fund of Western Metal Materials(Grant No.XBCL-3-14)
文摘In recent years, zinc based alloys as a new biodegradable metal material aroused intensive interests.However, the processing of Zn alloys micro-tubes(named slender-diameter and thin-walled tubes) is very difficult due to their HCP crystal structure and unfavorable mechanical properties. This study aimed to develop a novel technique to produce micro-tube of Zn alloy with good performance for biodegradable vascular stent application. In the present work, a processing method that combined drilling, cold rolling and optimized drawing was proposed to produce the novel Zn–5Mg–1Fe(wt%) alloy microtubes. The micro-tube with outer diameter of 2.5 mm and thickness of 130 μm was fabricated by this method and its dimension errors are within 10 μm. The micro-tube exhibits a fine and homogeneous microstructure, and the ultimate tensile strength and ductility are more than 220 MPa and 20% respectively. In addition, the micro-tube and stents of Zn alloy exhibit superior in vitro corrosion and expansion performance. It could be concluded that the novel Zn alloy micro-tube fabricated by above method might be a promising candidate material for biodegradable stent.
基金financially supported by Industrial Science Technology Project of Shaanxi Province (No. 2015GY160)Western Metal Materials Innovation Fund (No. XBCL03-18)International Cooperation and Exchanges of State Commission of Science Technology of China (No. 2014DFA30880)
文摘In this study, microstructural adjustments and mechanical properties of a cold-rolled nearβ-type alloy Ti-25Nb-3Zr-3Mo-2Sn (wt%) sheet were investigated.Microstructures and phase transformation products strongly depended on aging temperatures. Solution treatments within singleβ-phase field removed the stress-inducedα″martensites and produced a few new lath-shaped ones, but metastableβphase still dominated. This is exactly the reason why current alloy exhibits the lowest modulus (54 GPa) and best elongation to fracture (39%),but the worst yield strength of only 340 MPa, at solutiontreated state. A fairly large number of ellipsoidalωphase nanoparticles precipitated throughout parentβphase during aging at 380℃. Theseωnanoparticles possess remarkable strengthening effect, but deteriorate ductility seriously. A novel post-aging process was proposed to remove brittleωphase. By contrast, aging at 450℃resulted in sufficient precipitation of fine needle-like a phase. This brought about the best combination of high yield strength (770 MPa) and moderate elastic modulus(75 GPa) and good elongation (15%) for biomedical implants.
基金financial support of the National Natural Science Foundation of China(32071327)National Key Research and Development Program of China(2016YFC1102003)+2 种基金International Science and Technology Cooperation Base of Shaanxi Province(2017GHJD-014)Science and Technology Program of Shaanxi Province(2019GY-200)Key Research and Development Program of Shaanxi Province(2019ZDLSF03-06)。
文摘The gradient porous Ti3Zr2Sn3Mo25Nb(TLM)alloy rods were fabricated through sintering the alloyed powder to a solid core.The porous sample was then modified by a Micro Arc Oxidation(MAO)treatment in an electrolyte containing calcium and phosphate,a hydrothermal treatment enabled secondary microporous hydroxyapatite(HA)coating,and a further bone morphogenetic protein-2(BMP-2)loading treatment through immersion and freeze-drying.The treatment led to an orderly secondary microporous coating containing HA nano-particles and evenly distributed BMP-2 in the porous coatings.As a result,osteoblasts could adhere and grow well on the coatings with a high cell adhesion rate and cell functional activity.The in-situ shear testing indicated that the interfacial strength had been enhanced significantly.Improvement of the bond formation and osseointegration with the titanium implant is attributed to increased surface area for the cell to attach,creating voids for the cell to grow in,and activating titanium surface by introducing bioactive ingredients such as HA and BMP-2.
基金supported by the Science Challenge Project[No:TZ2018004]National Natural Science Foundation of China[Nos.51072159,51273159]+1 种基金Science and technology program of Shaanxi Province[No:2014K10-07]Technology Foundation for Selected Overseas Chinese Scholar,Department of Human Resources and Social Security of Shaanxi Province[No:2014-27].
文摘Hydroxyapatite(HA)synthesized by a wet chemical route was subjected to heavy ion irradiation,using4 Me V Krypton ion(Kr17+)with ion fluence ranging from 1×1013 to 1×1015 ions/cm2.Glancing incidence X-ray diffraction(GIXRD)results confirmed the phase purity of irradiated HA with a moderate contraction in lattice parameters,and further indicated the irradiation-induced structural disorder,evidenced by broadening of the diffraction peaks.High-resolution transmission electron microscopy(HRTEM)observations indicated that the applied Kr irradiation induced significant damage in the hydroxyapatite lattice.Specifically,cavities were observed with their diameter and density varying with the irradiation fluences,while a radiation-induced crystalline-to-amorphous transition with increasing ion dose was identified.Raman and X-ray photoelectron spectroscopy(XPS)analysis further indicated the presence of irradiationinduced defects.Ion release from pristine and irradiated materials following immersion in Tris(p H 7.4,37?)buffer showed that dissolution in vitro was enhanced by irradiation,reaching a peak at 0.1 dpa.We examined the effects of irradiation on the early stages of the mouse osteoblast-like cells(MC3 T3-E)response.A cell counting kit-8 assay(CCK-8 test)was carried out to investigate the cytotoxicity of samples,and viable cells can be observed on the irradiated materials.
基金financial support from the Queensland Centre for Advanced Materials Processing and Manufacturing(AMPAM)the ARC Research Hub for Advanced Manufacturing of Medical Devices(IH150100024)financial support from the Key Research and Development Program of Shaanxi Province(2019ZDLSF03-06)。
文摘This work investigates the strain rate dependence of dynamic recrystallization behaviour of high-purity zinc in room temperature compression under strain rates of 10^(-4)s^(-1),10-2s^(-1)and 0.5 s^(-1).Results from electron backscatter diffraction provide insight into the deformation and dynamic recrystallization mechanisms operative.Continuous dynamic recrystallization,twin-induced dynamic recrystallization,and discontinuous dynamic recrystallization are all active under compressive deformation at room temperature.Due to the high stacking fault energy of Zn,continuous dynamic recrystallization is the dominant mechanism while discontinuous dynamic recrystallization only operates in the early stages of compression at 10^(-4)s^(-1).Dynamic recrystallization kinetics are enhanced at higher strain rates(10^(-2)s^(-1)and 0.5s^(-1))due to an increased contribution from twin-induced dynamic recrystallization.The present study reveals that the controlling mechanisms for continuous dynamic recrystallization are basalslip and 2ndorder pyramidalslip activity.Because the activation of slip systems is mainly determined by crystallographic orientation,continuous dynamic recrystallization behaviour varies with grain orientation according to their propensity for basal and 2ndorder pyramidal slip.
