Effect of laser remelting on surface morphology and mechanical properties of laser deposition manufactured thin-walled Ti-6Al-4V alloy

• Published in: Rapid prototyping journal 2024-08, Vol.30 (8), p.1638-1647
• Main Authors: He, Bo, Tan, Jian, Yang, Guang, Yi, Junzhen, Wang, Yushi
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Fatigue life; Laser applications; Laser beam melting; Laser deposition; Lasers; Martensite; Mechanical properties; Melting; Metal fatigue; Microhardness; Morphology; Rapid prototyping; Surface properties; Surface roughness; Titanium alloys; Titanium base alloys
• ISSN: 1355-2546; 1355-2546; 1758-7670
• DOI: 10.1108/RPJ-02-2023-0052

Purpose This paper aims to systematically investigate the effect of laser remelting on the surface morphology and mechanical properties of laser deposition manufactured thin-walled Ti-6Al-4V alloy. Design/methodology/approach Thin-walled Ti-6Al-4V samples were prepared by laser deposition manufacturing (LDM) method and subsequently surface-treated by laser remelting in a controlled environment. By experiments, the surface qualities and mechanical properties of LDM Ti-6Al-4V alloy before and after laser remelting were investigated. Findings After laser remelting, the surface roughness of LDM Ti-6Al-4V alloy decreases from 15.316 to 1.813 µm, hard and brittle martensite presents in the microstructure of the remelted layer, and the microhardness of the laser remelted layer increases by 11.39%. Compared with the machined LDM specimen, the strength of the specimen including the remelted layer improves by about 5%, while the elongation and fatigue life decrease by about 72.17% and 64.60%, respectively. Originality/value The results establish foundational data for the application of laser remelting to LDM thin-walled Ti-6Al-4V parts, and may provide an opportunity for laser remelting to process the nonfitting surfaces of LDM parts.