Effect of surface roughness on tensile properties of electron beam melted Ti-6Al-4V alloy

Abstract

Electron beam melting (EBM) is a potential powder bed additive manufacturing technique used to produce high quality metallic parts for aerospace industry. The surface roughness of as-built EBM parts, however, might adversely affect the mechanical properties of Ti-6Al-4V alloys. In this study, a block cylindrical sample, an offset-standard tensile test specimen, and a standard tensile test specimen (diameter 6 mm, gage length 30 mm) were manufactured from Ti-6Al-4V alloys by EBM. Block cylindrical and offset-standard specimens were machined to standard tensile test specimen dimensions and diamond polished. Surface roughness of the specimens was measured in the as-built, as-built machined and polished condition. Mechanical tests were done in order to investigate the effect of surface roughness on tensile properties. Optical and scanning electron microscopy was utilized to characterize the surface and microstructure of specimens. The study showed that tensile properties considerably changed due to surface roughness introduced during EBM processing of specimens. © European Powder Metallurgy Association (EPMA)