Steady-state creep of a composite analysed by an energy balance method

The purpose of this paper is to analyse steady-state creep of a composite with spheroidal inclusions aligned along a tensile direction. It is an extension of a previous study of two-dimensional creep by Mori et al . (1997, Phil. Mag. Lett ., 75, 359). As in the previous study, interfacial diffusion and sliding play essential roles in inducing steady-state creep. A new method of analysis is introduced. Basically, it calculates energy dissipation rates from the rates of diffusional flow and sliding. Both rates are geometrically connected to a creep rate, in a manner depending on the shape of inclusions. By specifying the matrix creep law, a simple relation between the steady-state creep rate and an external tensile stress is obtained. Coble creep is also analysed as a simple and extreme case to which the present method can apply: grains in a polycrystal are treated as inclusions and deformation of plastic character is achieved by boundary diffusion and sliding.