Microstructure of Pure Ni Subjected to High Pressure Torsion
Plastic deformation leads to a structural refinement by introducing low angle dislocation boundaries and high angle boundaries in the initial coarse grains. To understand the mechanisms for the structural refinement and to establish the structurestrength relationship requires a precise characterization of key structural parameters, namely the boundary spacing and boundary misorientation angle. This study gives the results of such a characterization of pure Ni subjected to high pressure torsion (HPT) up to a strain of 300. The structural analysis was carried out by transmission electron microscopy in the longitudinal sample section in which the detailed structural features can be resolved. It is found that the microstructure in the HPT Ni samples is dominated by a lamellar structure. The spacing of the lamellar boundaries decreases and their misorientation angle increases with strain following a power law up to strain of 12, above which saturation is reached at a strain of about 34. The distribution of lamellar spacings normalized by their respective average values at each strain show an identical form. This scaling behavior is discussed also with reference to other metals and processing routes.
H.W.Zhang X.Huang N.Hansen R.Pippan
Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sc Danish-Chinese Center for Nanometals,Material Research Department,Riso National Laboratory,Technical Christian Doppler Laboratory for Local Analysis of Deformation and Fracture,Erich Schmid-lnstitute o
国际会议
5th International Conference on Nanomaterials by Severe Plastic Deformation(第五届剧烈塑性变形纳米材料国际会议)
南京
英文
529-534
2011-03-01（万方平台首次上网日期，不代表论文的发表时间）