Microstructure and mechanical deformation behavior of selective laser melted Ti6Al4V ELI alloy porous structures

Abstract

In the present work, microstructure, compressive properties and deformation behavior of selective laser melted (SLM) Ti6Al4V ELI porous structures were studied. After analyzing the phase composition and microstructure characteristics, a number of fine acicular a′ martensite (93.3%) and a bit β phase (6.6%) can be detected in SLM porous structures. Based on the experimental results and analyses, it can be found that when the porosity is constant, the yield strength of the SLM porous structure increases with increasing pore diameter. However, as the porosity increases, the mechanical properties of the SLM porous structures deteriorated. Of the SLM porous samples studied presently, those with porosity of 60% and pore diameter of 800 μm have the best compressive yield strength. Moreover, the relative density (d) of the SLM porous structures plays a vital role on the compressive properties (σ, MPa) of the SLM porous structures. The relationship between the SLM solid sample and the SLM porous sample can be established using the equation, i.e., σ = 1065 × d1.86.