Influence of post-processing techniques on residual stresses of SLM processed HPNGV

Abstract

In the present study, selective laser melting (SLM) technique employed to manufacture Inconel 718 high-pressure nozzle guide vane (HPNGV), an aero-engine component. The present work's focus is to investigate the influence of post-processing techniques on the residual stress of SLM fabricated HPNGV component. Two approaches for post-processing techniques such as standard post-processing (SPP) flow was compared with the customized post-processing (CPP) flow was investigated. Further, an attempt was also made to study the influence of component location on the baseplate and its effect on the magnitude of residual stress values in HPNGV components. The extensive residual stress measurements was carried out using X-ray diffraction technique. The results showed that the magnitude of compressive residual stress values obtained in the CPP technique was comparable with SPP technique. Further, HPNGV components fabricated on the build plate at different locations significantly affected the magnitude of residual stress values, which may be attributed to SLM processing and associated effects. The support structure removal sequence had a substantial contribution in controlling the distortion of the HPNGV component. The d-spacing value changes at different locations on the SLM processed samples due to changes in the chemical compositions due to inherent SLM processing characteristics. © 2021 The Society of Manufacturing Engineers