Abstract
High-temperature phase-boundary sliding has been studied by simple shear creep tests in two-phase (α/β)-brass bicrystals obtained by diffusion in the solid state. The constitutive law obtained is of the form σ∼ τn in which the exponent n is equal to 1 for low stresses and to 2 for stresses greater than a limiting value. To account for the experimental results, two mechanisms for sliding accommodation were considered, i.e., diffusion in the neighbourhood of phase-boundary asperities for low stresses and dislocation movement during deformation for higher stresses. The asperities, which develop in the phase boundary during the sliding, arise from the interaction between the interface and the dislocations of the β phase correlated with a phase transformation.
