The effect of lattice misfit on deformation mechanisms at high temperature

Abstract

Understanding the relationship between deformation mechanisms and microstructure is essential if one wants to fully exploit the potential of advanced nickel base superalloys and develop future alloys. In the present work, the influence of the lattice misfit between γ and γ ́ has been studied by means of in-situ loading experiments using neutron diffraction in combination with crystal plasticity modelling on RR1000 and Alloy 720Li. Both alloys were processed to generate three simplified uni-modal γ́ microstructures to allow determination of γ́ responses and experiments were carried out at 750°C. The results showed that a positive misfit strain increases the level of load partitioning from γ to γ ́ during plastic deformation introduced by uniaxial tensile loading. © (2011) Trans Tech Publications, Switzerland.