Deformation Mechanisms in Ni-Based Superalloys at Room and Elevated Temperatures Studied by In Situ Neutron Diffraction and Electron Microscopy

Polycrystalline Ni-based superalloys are one of the most frequently used materials for high temperature load-bearing applications due to their superior mechanical strength and chemical resistance. In this paper, we presented an in situ diffraction study on tensile deformation behavior polycrystalline superalloy VDM® Alloy 780 at temperatures up 500 °C performed STRESS-SPEC neutron diffractometer Heinz Maier-Leibnitz Zentrum. A detailed microstructural investigation was carried out by electron microscopy before after testing. The results these studies allowed us determine mechanism differently orientated grains. It is shown that behavior, which mainly dislocation motion shearing γ′-precipitates, does not change range. strongly anisotropic depends grain orientation. macroscopic hardening can be attributed plastic grains, where (200) lattice planes were perpendicular loading direction. Accordingly, a remaining strain density detected predominantly