Designing very high-cycle fatigue specimens of additively manufactured Ti-6Al-4V with different porosities and microstructures

Abstract

High cycle fatigue properties of material obtained with additive manufacturing (AM) processes such as LPBF (Laser Powder Bed Fusion) remain misunderstood. These properties are complex due to the porous and anisotropic features of AM parts. Moreover, a high number of process parameters can influence the obtained fatigue behavior. In this context, a rapid determination of the high and very high cycle fatigue properties is necessary in order to optimize process parameters with regard to fatigue response. This first work aims to produce test pieces with different porosity rates and microstructures. The processing and post-processing parameters leading to different porosity rates, porosity size distribution and microstructure are determined and presented. In a future work, the fatigue response will be then compare using two accelerated fatigue determination methods: ultrasonic fatigue testing and fatigue limit evaluation through lock-in thermography.