Effect of laser scan rotation on the microstructure and mechanical properties of laser powder bed fused Haynes 282

Abstract

Haynes 282 is a weldable, γ′ strengthened Ni-based superalloy and is a suitable candidate for aerospace and power-generation applications. Laser powder bed fusion (LPBF) of Haynes 282 is gaining attention recently due to its superior mechanical properties than its conventional counterparts. In spite of the superior mechanical properties, there are significant challenges concerning crystallographic anisotropy. One of the critical but less studied parameters that influence crystallographic anisotropy is the laser scan rotation angle. This study investigates the effect of laser scan rotation angle on the microstructure and subsequently on the mechanical properties. The samples fabricated with 90° scan rotation exhibited stronger texture while the samples with 137° rotation had weaker texture than samples with 67°. Further, three-dimensional Finite difference-Monte Carlo simulations were performed to understand the microstructure evolution with varying process parameters. The experimental and simulated microstructures are quantitatively compared using 2-point correlations. The texture and grain morphology evolution are explained based on melt pool morphology and microstructure simulations. Mechanical properties of as-built and aged samples are estimated using theoretical models and agree well with the experimental results.