Orientation-dependent low-cycle fatigue and grain boundary evolution in DMLS-fabricated Haynes 282 superalloy

Abstract

This study investigates the effect of build orientation on the fatigue performance of Haynes 282 alloy manufactured via Direct Metal Laser Sintering at 0°, 45°, and 90°. Fatigue tests revealed superior service life for 0° and 45° orientations, attributed to equiaxed grains and high-angle grain boundaries identified by EBSD. Vertical builds exhibited columnar grains and reduced fatigue resistance. This work provides the first systematic correlation between grain boundary character and low-cycle fatigue behavior in DMLS-manufactured Haynes 282, expanding current understanding beyond Inconel-based systems and offering insights for orientation-based design optimization in critical high-temperature applications.