Executive Summary : | Titanium alloys are widely used in the aerospace and defense industry due to their specific strength and corrosion behavior. However, extraction and processing of these alloys can be costly. Additive manufacturing techniques like selective laser sintering, selective laser melting, electron beam melting, direct metal deposition, and laser engineered net shaping have gained worldwide importance due to their cost-effectiveness. However, these techniques can lead to porosities and chemical in-homogeneity, deteriorating important mechanical properties like fatigue. Fatigue properties are crucial in this sector, as the material can be subjected to low cycle fatigue (LCF) or high cycle fatigue (HCF) depending on the application type. The project proposal aims to understand the effect of as-built, heat treated, and hot isostatic pressed (HIPped) microstructure on the fatigue resistance of Ti-6Al-4V alloy. The fatigue resistance values of as-built, heat treated, and HIPped samples can be compared with conventionally prepared samples. Additionally, the fatigue resistance may be affected by the crystallographic texture of the material. The work methodology involves building cylindrical samples using SLM process with 40-60 µm pre-alloyed powder in an argon atmosphere, heating the platform to reduce residual stresses, and generating three different microstructures: as-built, as-built+heat treated, and as-built+HIPped. All samples will be characterized using XRD, SEM, SEM-EDS, EBSD, X-ray texture, and X-ray tomography. Fatigue tests will be conducted for all three microstructures and the fatigue failed samples. |