Paper Title:

Microstructural Evolution of Mg-4Nd Alloy Processed by High-Pressure Torsion

Periodical Materials Science Forum (Volumes 667 - 669)
Main Theme Nanomaterials by Severe Plastic Deformation: NanoSPD5
Edited by Jing Tao Wang, Roberto B. Figueiredo and Terence G. Langdon
Pages 391-396
DOI 10.4028/
Citation Jing Bai et al., 2010, Materials Science Forum, 667-669, 391
Online since December 2010
Authors Jing Bai, Feng Xue, Saleh N. Alhajeri, Terence G. Langdon
Keywords Hardness, High Pressure Torsion (HPT), Homogeneity, Magnesium Alloy, Microstructure
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Disks of as-extruded Mg-4Nd alloy were processed by high-pressure torsion (HPT) through ¼ 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.