Creep deformation behavior of spherical Al2O3 particle-reinforced Al–Mg matrix composites at high temperatures

Abstract The steady-state creep behavior of 10 vol% spherical Al 2 O 3 particle-reinforced Al–5 at% Mg matrix composites fabricated by ingot metallurgy was investigated in the compression mode. The composites had a moderate diffusional accommodation rate and were free of fine dispersoids, e.g. oxides or precipitates. Threshold stress behavior in the low-strain-rate region below the diffusional accommodation rate was observed despite the fact that there were no fine dispersoids. In the high-strain-rate region, power-law creep controlled by plastic accommodation was observed, while linear creep controlled by diffusional accommodation was not observed around the diffusional accommodation rate. It was explained that because strengthening by the spherical particles through load transfer is quite small, diffusional-accommodation-controlled creep can be scarcely observed.