Abstract
An obstacle hindering the applicability of surface modification techniques such as laser peening (LP) in high temperature systems stems from thermally-driven degradation of desirable, strain-induced material modifications. Illustrated in this work is a novel LP scheme termed laser peening plus thermal microstructure engineering (LP + TME) comprised of cyclic LP and the addition of intermittent 600 °C (0.55Tm) heat treatments designed to impart thermally-stable microstructural modifications in additively manufactured (AM) Inconel 718 (In718). Instrumented microindentation uncovered significant surface and sub-surface hardness enhancements exceeding 600 HV following LP + TME, a 20% increase over the as-built material. High magnitude compressive residual stresses exceeding −310 MPa were also measured following a 350-h 600 °C thermal exposure; a 25% increase compared to the material subjected to only a single laser shot. Thermal stabilization and overall material enhancement were determined to be the result of the formation of thermally-stable subgrains, subgrain and grain growth regulation through pinning effects, and dislocation-precipitate interactions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
