Effect of serrated grain boundaries on the creep property of INCONEL 718 superalloy

The present study investigates the effect of serrated grain boundary with zigzag morphology on the high temperature creep deformation of IN718 superalloy. The experimental results have indicated that the morphology of grain boundary can be a function of heat-treatment condition. Experimental work includes XRD, DSC analysis, and SEM microstructure observations in order to investigate the underlying mechanism for the formation of zigzag grain boundary. Creep test under 650?C/625MPa has been conducted on samples of IN718 with and without zigzag grain boundaries in order to determine its effects on deformation mechanisms. In conclusions, an improvement of 400 hours creep rupture life has been attributed by the serrated grain morphology. (AU) © 2010 by The Materials, Metals, & Materials Society. All rights reserved.