In-situ study of adjacent grains slip transfer of Inconel 718 during tensile process at high temperature

Adjacent grains slip transfer is an important mechanism for metal adaptation to incompatibilities in intergranular deformation. Thus, this paper investigates slip transmission at grain boundaries (GBs) and annealed twin boundaries (TBs) in Inconel 718 (IN718) alloy using in-situ tensile test at 650 degrees C by integrating slip trace analysis and the crystal plasticity finite element method (CPFEM). Results show that the m alpha beta criterion, based on the match of intersection lines between slip planes to GB planes and slip directions, is more reasonable in predicting induced activated slip systems than Luster-Morris m 'alpha beta criterion. In addition, slip transfer tended to occur at m 'alpha beta > 0.83 and Delta b(1/b) < 0.44 or m alpha beta > 0.82 and Delta b(1/b) < 0.46 for general GBs; when m 'alpha beta > 0.92 or m alpha beta > 0.93, continuous slip transfer is a crucial mechanism to coordinate strain and reduce stress concentration. Furthermore, the acceptable criteria for slip transfer at TBs are theta approximate to 0 and Delta b(1/b) < 0.6 by experimental and computational results. This study deepens the understanding of the adjacent grains slip transfer behavior of IN718 and also provides a new strategy to study the deformation behavior of Nickel-based superalloys.