Constrained Friction Processing(CFP),a novel friction-based technique,has been developed to efficiently process fine-grained magnesium(Mg)rods,expanding the potential applications of biodegradable Mg alloys in medical...Constrained Friction Processing(CFP),a novel friction-based technique,has been developed to efficiently process fine-grained magnesium(Mg)rods,expanding the potential applications of biodegradable Mg alloys in medical implants.This study investigates the enhancement of mechanical properties through the implementation of multiple pass CFP(MP-CFP)in comparison to the conventional single pass CFP.The results reveal a substantial improvement in compressive yield strength(CYS),ultimate compressive strength,and failure plastic strain by 11%,28%,and 66%,respectively.A comprehensive analysis of material evolution during processing and the effects of the final microstructure on mechanical properties was conducted.The intricate material flow behavior during the final plunge stage of MP-CFP results in a reduced intensity of local basal texture and macrotexture.The diminished intensity of basal texture,combined with a low geometrical compatibility factor at the top of the rod after MP-CFP,effectively impedes slip transfer across grain boundaries.This leads to a local strain gradient along the compression direction,ultimately contributing to the observed enhancement in mechanical properties.The Mg-0.5Zn0.3Ca(wt.%)alloy,after texture modification by MP-CFP,exhibits a competitive CYS compared with other traditional methods,highlighting the promising application potential of MP-CFP.展开更多
In order to obtain Mg alloys with fine microstructures and high mechanical performances,a novel friction-based processing method,name as“constrained friction processing(CFP)”,was investigated.Via CFP,defect-free Mg-...In order to obtain Mg alloys with fine microstructures and high mechanical performances,a novel friction-based processing method,name as“constrained friction processing(CFP)”,was investigated.Via CFP,defect-free Mg-Zn-Ca rods with greatly refined grains and high mechanical properties were produced.Compared to the previous as-cast microstructure,the grain size was reduced from more than 1 mm to around 4μm within 3 s by a single process cycle.The compressive yield strength was increased by 350%while the ultimate compressive strength by 53%.According to the established material flow behaviors by“tracer material”,the plastic material was transported by shear deformation.From the base material to the rod,the material experienced three stages,i.e.deformation by the tool,upward flow with additional tilt,followed by upward transportation.The microstructural evolution was revealed by“stop-action”technique.The microstructural development at regions adjacent to the rod is mainly controlled by twinning,dynamic recrystallization(DRX)as well as particle stimulated nucleation,while that within the rod is related to DRX combined with grain growth.展开更多
基金Ting Chen thanks the China Scholarship Council for the Award of a Fellowship(No.202006230137)Benjamin Klusemann ac-knowledges funding by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-project number 544306307+1 种基金Banglong Fu acknowledge the financial support of the National Natural Science Foundation of China(Grant No.52405386)State Key Laboratory of Precision Welding&Joining of Materials and Structures(Grant No.MSWJ-24M13).
文摘Constrained Friction Processing(CFP),a novel friction-based technique,has been developed to efficiently process fine-grained magnesium(Mg)rods,expanding the potential applications of biodegradable Mg alloys in medical implants.This study investigates the enhancement of mechanical properties through the implementation of multiple pass CFP(MP-CFP)in comparison to the conventional single pass CFP.The results reveal a substantial improvement in compressive yield strength(CYS),ultimate compressive strength,and failure plastic strain by 11%,28%,and 66%,respectively.A comprehensive analysis of material evolution during processing and the effects of the final microstructure on mechanical properties was conducted.The intricate material flow behavior during the final plunge stage of MP-CFP results in a reduced intensity of local basal texture and macrotexture.The diminished intensity of basal texture,combined with a low geometrical compatibility factor at the top of the rod after MP-CFP,effectively impedes slip transfer across grain boundaries.This leads to a local strain gradient along the compression direction,ultimately contributing to the observed enhancement in mechanical properties.The Mg-0.5Zn0.3Ca(wt.%)alloy,after texture modification by MP-CFP,exhibits a competitive CYS compared with other traditional methods,highlighting the promising application potential of MP-CFP.
基金the China Scholarship Council for the award of fellowship and funding(No.202006230137)。
文摘In order to obtain Mg alloys with fine microstructures and high mechanical performances,a novel friction-based processing method,name as“constrained friction processing(CFP)”,was investigated.Via CFP,defect-free Mg-Zn-Ca rods with greatly refined grains and high mechanical properties were produced.Compared to the previous as-cast microstructure,the grain size was reduced from more than 1 mm to around 4μm within 3 s by a single process cycle.The compressive yield strength was increased by 350%while the ultimate compressive strength by 53%.According to the established material flow behaviors by“tracer material”,the plastic material was transported by shear deformation.From the base material to the rod,the material experienced three stages,i.e.deformation by the tool,upward flow with additional tilt,followed by upward transportation.The microstructural evolution was revealed by“stop-action”technique.The microstructural development at regions adjacent to the rod is mainly controlled by twinning,dynamic recrystallization(DRX)as well as particle stimulated nucleation,while that within the rod is related to DRX combined with grain growth.
