中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 32 No. 8 August 2022 |
(1. Institute of Materials Processing and Intelligent Manufacturing, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China;
2. Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China)
Abstract:The effect of electropulsing treatment on microstructure and mechanical strength of laser metal deposited Ti-6Al-4V alloy was investigated in order to eliminate the anisotropy in strength of laser metal deposited Ti-6Al-4V alloy by tensile tests, optical microscopy, scanning electron microscopy, electron back-scattered diffraction analyses and transmission electron microscopy. With increasing applied voltages from 0 to 130 V, the evolution of microstructure within columnar β grains followed the sequence of α′ martensite → colony α structure → basket-weave α structure. The electropulsing treated at 130 V weakened the texture of martensite within β grains. The as-built Ti-6Al-4V alloy showed an anisotropy in yield strength (6.2%). After processing at 130 V, the anisotropy in yield strength was reduced to 0.6%, which was attributed to the almost equivalent distribution of Schmid factor in the samples deformed along different orientations.
Key words: laser metal deposition; Ti-6Al-4V alloy; yield strength; anisotropy; electropulsing