Study on Effect of Laser Peening on Inconel 718 produced by DMLS technique 2019-28-0146
In Additive manufacturing, Direct Metal Laser Sintering is a
rapid manufacturing technique used for manufacturing of functional
components. Finely pulverized metal is melted using a high-energy
fibre laser, by Island principle strategy produces mechanically and
thermally stable metallic components with reduced thermal
gradients, stresses & at high precision. Inconel is an
austenitic chromium nickel based super alloy often used in the
applications which require high strength & temperature
resistant. It can retain its properties at high temperature, e.g.
Engine components in aerospace, exhaust system in automobile
applications etc. Here we attempts to analyze the effect of laser
shock peening on DMLS Inconel 718 sample. Microstructure shows
elliptical shaped structure and formation of new grain boundaries.
Surface roughness of the material has been increased due to effect
of laser shock pulse & ablative nature. 13 % Increase in macro
hardness on the surface. Depth wise micro hardness was
investigated, found to be 17% increase on the sub layer of the
material due to the effect of hardened matrix formed by
precipitation hardening and grain size refinement attributed by
laser shock peening. SEM analysis shows larger grains are being
refined into smaller grains. The residual stress analysis was
carried out using sin2 Ψ method of X-ray Diffraction. The results
indicate compressive residual stress values have increased.