Temperature dependence of deformation mechanisms in a single crystal nickel-base alloy with high volume fraction of gamma' phase

The temperature dependence of the yield stress was analyzed in SRR99. High and low temperature regimes can be distinguished. TEM studies show that in the low-temperature regime paired loops expand from the gamma' phase leading to high dislocation densities in matrix channels. At high temperatures deformation starts by expansion of dislocation dipoles in the matrix. The experimental results are compared with the temperature dependence of CRSS values calculated for dipole expansion in narrow matrix channels.