Microstructural Evolution of Mg-4Nd Alloy Processed by High-Pressure Torsion
Disks of as-extruded Mg-4Nd alloy were processed by high-pressure torsion (HPT) through V* to 5 turns at room temperature. The first 1/4 turn of HPT induces large numbers of twins and some dislocation tangles in the center region of the disk. With increase of torsional straining, the twinning is inhibited gradually and the dislocation density increases relating to the formation of dislocation substructures and ultimately transforming to high fractions of equiaxed gains which have an average grain size of~200 nm and high-angle boundaries. HPT significantly improves the values of microhardness of this alloy. The hardness values in both the central and edge regions show a sharp rise after HPT for 1/4 turn and exhibit nearly saturation after 1/2 turn although there is a trend of a slight increase with increasing numbers of turns. The experimental results suggest more homogeneous microstructures may be produced by larger numbers of turns in the HPT process.
Jing Bai Feng Xue Saleh N.Alhajeri Terence G.Langdon
School of Materials Science and Engineering Southeast University,Nanjing,Jiangsu 211189,China Department of Manufacturing Engineering,College of Technological Studies PAAET,P.O.Box 42325,Shuwaik Materials Research Group,School of Engineering Sciences University of Southampton,Southampton SO17 1
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
391-396
2011-03-01（万方平台首次上网日期，不代表论文的发表时间）