High-Temperature Solid Particle Erosion Behavior of Laser Powder Bed Fused Inconel 718

Abstract

The failure of turbine blades due to solid particle erosion is a serious concern in aviation applications. This research investigates the solid particle erosion behavior of laser powder bed fused IN718 alloy for the effect of temperature (400 °C, 500 °C, and 600 °C) and impact angle (45 deg and 90 deg) in a gas-jet erosion setup. The erosion rate progressively increased with the test temperature and it is significantly higher in the 45 deg eroded samples. The eroded samples were characterized for residual stress distribution, surface topography, and surface roughness using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and 3D optical profilometer. Compressive residual stress is evident in all eroded samples, and higher residual stress is measured in the 90 deg eroded samples. Ploughing, crater lip formation, and cracking are the erosion features observed in the 45 deg eroded samples. In comparison, localized plastic deformation, platelet mechanisms, and cracked ridges are observed in the 90 deg eroded samples. Crack formation at 600 °C test condition is attributed to severe erosion degradation in both the impact conditions (45 deg and 90 deg). The as-printed and solution-double aged samples were thoroughly investigated for microstructure and microhardness distribution at the region parallel and perpendicular to the build direction.