Investigation of the compressive creep behavior of AZ91D magnesium alloy

The creep resistance of AZ91D alloy has been studied in uniaxial compression tests at temperature ranges from 275 degrees C to 325 degrees C. The initial microstructure of the alloy consists of alpha phase and beta phase precipitated in the grain boundary. The minimum creep rate dependence on applied stress and the temperature is also analyzed in detail. We find that the stress exponent n is close to the theoretical values (3 or 5) and the activation energy Q for creep varies from 121 kJ/mol to 171 kJ/mol. Creep could be controlled by higb-temperature climb and cross-slip of dislocation at different temperatures. (c) 2006 Elsevier B.V. All rights reserved.