Surface Morphology and Microstructural Features of LPBF-Printed Superalloy Turbine Blade Subjected to HIP, Heat Treatment, and Shot Peening

Laser-based powder bed fusion (LPBF) is one of the attractive methods of powder bed fusion additive manufacturing technology to produce lightweight metal products with complex shapes for the aviation/aerospace industry. In this work, the turbine blades were manufactured applying an industrial LPBF system and commercial Inconel 718 powder. The LPBF-built turbine blade superalloy parts were then thermomechanically post-processed to provide surface integrity and material properties. The hot isostatic pressing and heat treatment were applied to provide the required grain structure and density. The subsurface nanostructuring, compressive residual stress, and a new surface microrelief formation were obtained by a surface shot peening. The results show that the applied combined thermomechanical post-treatment increased the hardening intensity in the subsurface and bulk by ~68% and ~35%, respectively. Shot peening led to a ~50% decrease in surface roughness.