The cyclic rotating−bending(CRB)processes under different deformation conditions were carried out to refine the microstructure and improve the mechanical properties of the 65Cu−35Zn brass tubes.The microstructure and ...The cyclic rotating−bending(CRB)processes under different deformation conditions were carried out to refine the microstructure and improve the mechanical properties of the 65Cu−35Zn brass tubes.The microstructure and the mechanical properties in the axial direction of the tubes after the CRB process were studied with the OM,EBSD and conventional tensile test.To obtain the accumulated effective plastic strain of the tube during the CRB process,the FEM simulation was also executed.The results show that the average grain size decreases with the increase of rotation time at RT,and with the decrease of bending angle at 200℃.With the increase of accumulated effective plastic strain during the CRB process,the reduction rate of average grain size of the brass tube increases,the tensile strength of the brass tube increases in wave shape and the elongation increases first and then sharply decreases.展开更多
The dynamic conditions for plastic deformation mechanism,surface source mechanism,interface source mechanism and creep mechanism in the diffusion bonding process are proposed.Based on these dynamic conditions,a model ...The dynamic conditions for plastic deformation mechanism,surface source mechanism,interface source mechanism and creep mechanism in the diffusion bonding process are proposed.Based on these dynamic conditions,a model for void closure in the diffusion bonding process is derived.The effects of diffusion bonding parameters on the bonding mechanisms are analyzed.For the diffusion bonding process of TC4 alloy,at a low diffusion bonding temperature or pressure,or for a short time,the interface source mechanism plays a main role.But,the creep mechanism is the dominant mechanism and operates until the diffusion bonding is fulfilled.As the diffusion bonding time increases,the surface source and interface source mechanism enhance and then stop at a certain stage of diffusion bonding,while the creep mechanism enhances continuously.As the diffusion bonding temperature or pressure increases,the interface source mechanism weakens and the other mechanisms enhance.The maximum and average errors between the calculated and the experimental results in the diffusion bonding for TC4 alloy are 12.86% and 5.79%,respectively.展开更多
基金the National Natural Science Foundation of China(No.51304046)the Grant-in-Aid for Young Scientists(B)of Japan Society for the Promotion of Science of Japan(No.25870594)。
文摘The cyclic rotating−bending(CRB)processes under different deformation conditions were carried out to refine the microstructure and improve the mechanical properties of the 65Cu−35Zn brass tubes.The microstructure and the mechanical properties in the axial direction of the tubes after the CRB process were studied with the OM,EBSD and conventional tensile test.To obtain the accumulated effective plastic strain of the tube during the CRB process,the FEM simulation was also executed.The results show that the average grain size decreases with the increase of rotation time at RT,and with the decrease of bending angle at 200℃.With the increase of accumulated effective plastic strain during the CRB process,the reduction rate of average grain size of the brass tube increases,the tensile strength of the brass tube increases in wave shape and the elongation increases first and then sharply decreases.
基金supported by the National Natural Science Foundation of China (Grant No. 50975234)
文摘The dynamic conditions for plastic deformation mechanism,surface source mechanism,interface source mechanism and creep mechanism in the diffusion bonding process are proposed.Based on these dynamic conditions,a model for void closure in the diffusion bonding process is derived.The effects of diffusion bonding parameters on the bonding mechanisms are analyzed.For the diffusion bonding process of TC4 alloy,at a low diffusion bonding temperature or pressure,or for a short time,the interface source mechanism plays a main role.But,the creep mechanism is the dominant mechanism and operates until the diffusion bonding is fulfilled.As the diffusion bonding time increases,the surface source and interface source mechanism enhance and then stop at a certain stage of diffusion bonding,while the creep mechanism enhances continuously.As the diffusion bonding temperature or pressure increases,the interface source mechanism weakens and the other mechanisms enhance.The maximum and average errors between the calculated and the experimental results in the diffusion bonding for TC4 alloy are 12.86% and 5.79%,respectively.
