Surface nanocrystallization of commercial pure titanium by shot peening  

作　　者：MA Guang LUO Yu CHEN Chun-huan REN Rui-ming WU Wei LI Zhi-qiang ZENG Yan-song 

机构地区：[1]School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,China [2]Beijing Aeronautical Manufacturing Technology Research Institute,Beijing 100024,China

出　　处：《中国有色金属学会会刊:英文版》2004年第z1期204-209,共6页Transactions of Nonferrous Metals Society of China

基　　金：Project(50171017) support by the National Natural Science Foundation of China; project(2001101054) supported by the Science and Technology Foundation of Liaoning Province; project(02H25008) supported by the Aeronautical Basic Science Foundation

摘　　要：The surface nanostructures of commercial pure titanium was realized by the modified shot peening equipment commonly used in industry through the special treatment process. The results show that high-energy-shot-peening(HESP) commonly used to prepare nanostructured surface layers can be achieved by the increase of pill size, pill speed, and treatment time in the commercial shot peening equipment. XRD, SEM and TEM were used to characterize the surface layer microstructure of treated specimens. The analytic results show that the main deformation mode of commercial pure Ti is twinning. At the beginning of deformation, the dislocations are formed and twins occur within or on plane, then twins in intersection plane appear, and at last the twin characteristics disappear in the surface layer after longer treatment time. The deformation layer depth increases with treatment time in a certain period when the pill size and speed are unchanged. And in the severe plastic deformation (SPD) layer in which the twins are not identified easily by using SEM, the nanocrystalline microstructures are found under TEM. The finest grain size in the surface layer is about 40 nm, and the depth of nanostructured layers is over 60 μm. The microhardness of the nanostructured surface layers is enhanced significantly after shot peening compared with that of the initial simple.

关 键 词：surface nanocrystallization commercial pure titanium PEENING HARDNESS 

分 类 号：TG174[金属学及工艺—金属表面处理]