Effect of Stress Relieving Heat Treatment on the Microstructure and High-Temperature Compressive Deformation Behavior of Ti-6Al-4V Alloy Manufactured by Selective Laser Melting

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 49; no. 11; pp. 5763 - 5774
• Main Authors: Kim, Young-Kyun, Park, Soon-Hong, Kim, Yong-Jin, Almangour, Bandar, Lee, Kee-Ahn
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2018; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Compression tests; Compressive properties; Compressive strength; Deformation; Elongation; Heat treating; Heat treatment; Laser beam melting; Martensite; Materials Science; Metallic Materials; Microstructure; Nanotechnology; Stress relieving; Structural Materials; Surfaces and Interfaces; Thin Films; Titanium base alloys; Yield strength
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-018-4864-0

This study aims to investigate the effect of stress relieving heat treatment on the microstructure and high-temperature compressive deformation behavior of the Ti-6Al-4V alloy, manufactured by selective laser melting. Initial microstructural observation confirmed elongated prior β grains in the building direction of both specimens (as-fabricated and heat-treated specimens). Along with such, the as-fabricated specimen only featured α′ -martensite phase, while the heat-treated specimen featured α′ -martensite and some α and β phases. Compression tests carried out at room temperature gave yield strengths of 1365 and 1138 MPa for the as-fabricated and heat-treated specimens, respectively. Such values are similar or greater than those of commercial wrought materials. The compressive fracture strain significantly increased after heat treatment. There was a general tendency of reducing yield strength as compressive temperatures increased. At temperatures greater than 700 °C, the as-fabricated and heat-treated specimens achieved similar strength. Microstructural observation after deformation confirmed that the initial microstructure was retained up to temperatures of 500 °C. At 700 °C or greater, both specimens showed drastic microstructural evolution.