Enhanced Surface Mechanical Properties and Microstructure Evolution of Commercial Pure Titanium Under Electropulsing-Assisted Ultrasonic Surface Rolling Process  

作　　者：Yong-Da Ye Xiao-Pei Li Zhi-Yan Sun Hai-Bo Wang Guo-Yi Tang 

机构地区：[1]Advanced Materials Institute, Graduate School at Shenzhen,Tsinghua University [2]School of Materials Science and Engineering, Tsinghua University

出　　处：《Acta Metallurgica Sinica(English Letters)》2018年第12期1272-1280,共9页金属学报（英文版）

基　　金：financial support from the Shenzhen Development and Reform Commission Engineering Laboratory Project(Shenzhen development and Reform2015-1033);the Shenzhen Science and Technology supporting Plan Project(GJHS20160331183313435);the China Postdoctoral Science Foundation(No.2017M620770)

摘　　要：The effects of electropulsing-assisted ultrasonic surface rolling process on surface mechanical properties andmicrostructure evolution of commercial pure titanium were investigated. It was found that the surface mechanical prop-erties were significantly enhanced compared to traditional ultrasonic surface rolling process （USRP）, leading to smallersurface roughness and smoother morphology with fewer cracks and defects. Moreover, surface strengthened layer wasremarkably enhanced with deeper severe plastic deformation layer and higher surface hardness. Remarkable enhancementsof surface mechanical properties may be related to the gradient refined microstructure, the enhanced severe plasticdeformation layer and the accelerated formation of sub-boundaries and twins induced by coupling effects of USRP andelectropulsing. The primary intrinsic reasons for these improvements may be attributed to the thermal and athermal effectscaused by electropulsing treatment, which would accelerate dislocation mobility and atom diffusion.The effects of electropulsing-assisted ultrasonic surface rolling process on surface mechanical properties andmicrostructure evolution of commercial pure titanium were investigated. It was found that the surface mechanical prop-erties were significantly enhanced compared to traditional ultrasonic surface rolling process （USRP）, leading to smallersurface roughness and smoother morphology with fewer cracks and defects. Moreover, surface strengthened layer wasremarkably enhanced with deeper severe plastic deformation layer and higher surface hardness. Remarkable enhancementsof surface mechanical properties may be related to the gradient refined microstructure, the enhanced severe plasticdeformation layer and the accelerated formation of sub-boundaries and twins induced by coupling effects of USRP andelectropulsing. The primary intrinsic reasons for these improvements may be attributed to the thermal and athermal effectscaused by electropulsing treatment, which would accelerate dislocation mobility and atom diffusion.

关 键 词：Electropulsing-assisted ultrasonic surface rolling process （EP-USRP） Commercial pure titanium Roughness Hardness Microstructure evolution 

分 类 号：TG339[金属学及工艺—金属压力加工] TG146.23[一般工业技术—材料科学与工程]