Microstructures and mechanical properties of pure tantalum processed by high-pressure torsion

6th International Conference on Nanomaterials by Severe Plastic Deformation

材料科学;化学

Huang, Y.^1 ; Maury, N.^2 ; Zhang, N.X.^1 ; Langdon, T.G.^1,3

Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, United Kingdom^1

École Nationale Supérieure des Ingénieurs en Arts Chimiques et Technologiques, National Polytechnic Institute of Toulouse (INPT), 31077 Toulouse CEDEX 04, France^2

Departments of Aerospace and Mechanical Engineering and Materials Science, University of Southern California, Los Angeles CA 90089-1453, United States^3

关键词: Body-centred-cubic structures;    Electron back scatter diffraction;    Grain boundary migrations;    Grain size;    High pressure torsions;    Microhardness measurement;    Microstructures and mechanical properties;    Recovery process;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/63/1/012100/pdf
DOI  :  10.1088/1757-899X/63/1/012100

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

A body-centred cubic (BCC) structure metal, tantalum, was processed by high- pressure torsion (HPT) at room temperature with different numbers of rotations. The microstructural evolution was studied by electron backscatter diffraction (EBSD). The grain sizes were significantly refined at the disk edge area in the early stages of deformation (N 0.5) but tended to attain saturation after the numbers of rotations was increased to N 5. As the deformation continued, some coarse grains appeared in the disk edge areas and it appeared that there was structural recovery at the expense of grain boundary migration in the tantalum during HPT processing. Microhardness measurements showed the hardness gradually evolved towards a more homogenized level across the disk surfaces as the numbers of rotations increased. The hardness level after N 10 turns was slightly lower than after N 5 turns, thereby indicating the occurrence of a recovery process after 5 turns.