ECAP变形对超细晶铜再结晶行为的影响

Effect of ECAP deformation on the recrystallization behavior of ultra-fine grained copper

为研究ECAP变形对超细晶铜再结晶行为的影响,室温条件下对纯铜进行12道次等通道转角挤压(ECAP)变形,分别在100、150、280℃下对不同道次的超细晶铜进行退火处理,分析其硬度及微观组织变化规律.结果表明:经12道次ECAP变形后,铜的晶粒尺寸细化到约250 nm,硬度达146 HV;随着变形道次增加,超细晶铜的热稳定性降低,软化速度加快,在150℃退火时,1道次超细晶铜完成再结晶的时间约为20 h,12道次为0.5 h;12道次ECAP超细晶铜等温退火温度越高,完成再结晶时间越短,150℃完成再结晶时间约为1200 s,200℃时缩短至600 s,280℃时再结晶仅需50 s;利用Arrhenius公式计算了再结晶激活能,1道次约为1 eV,12道次为0.78 eV,ECAP变形降低了铜的再结晶激活能.

To study the effect of equal channel angular compression(ECAP)deformation on the recrystallization behavior of ultra-fine grained copper,12 times of ECAP deformation were performed on pure copper at room temperature.The ultra-fine grained copper of different passes was annealed at 100,150,and 280℃,and the changes of hardness and microstructure were analyzed.Results show that after 12 times of ECAP deformation,the grain size of the copper was refined to^250 nm,and the hardness reache 146 HV.With the increase of the deformation pass,the thermal stability of the ultra-fine grain copper decreased,and the softening rate increased.When annealing occurred at 150℃,the time required for the recrystallization of the ultra-fine grained copper in one pass was about 20 h,and that for 12 passes was 0.5h.The higher the isothermal annealing temperature of the 12-pass ECAP ultra-fine crystal copper was,the shorter the recrystallization time was.The recrystallization time was about 1200 s at 150℃,which was shortened to 600s at 200℃,and it only cost 50s to recrystallize at 280℃.The activation energy of recrystallization was calculated by the Arrhenius formula,with 1 pass in 1eV and 0.78eV in 12 passes.The ECAP deformation reduced the reactivation activation energy of the copper.