Damage tolerance evaluation of a unit cell plane based on electron beam powder bed fusion (E-PBF) manufactured Ti6Al4V alloy

Abstract

Electron beam powder bed fusion (E-PBF) enables the fabrication of new and complex light-weight structures within short process times. However, increasing complexity of the producible components leads to complex damage mechanisms and interactions which can not sufficiently be represented by typical material properties such as ultimate tensile strength or fatigue strength. In the current research, the damage tolerance was investigated within a single unit cell plane for a stretch-dominated lattice type under uniaxial cyclic loading based on the E-PBF manufactured Ti6Al4V alloy. During the experiments, a combination of application-specific optical measurement techniques such as digital image correlation and thermography were used to capture occurring material responses. In particular, a clear relationship between local deformation and temperature increase is visible. In comparison to conventionally manufactured material, similar mechanical properties can be achieved in low cycle fatigue range. Furthermore, captured material responses could be used as a basis for future monitoring systems in order to enable a reliable application in safety-relevant components.