Inclusion stresses in a two-phase alloy deformed to a plastic strain of 1%

An X-ray technique has been used to measure the strains in silicon particles in a 7Si, 0·43Mg aluminium casting alloy during pure bending. Following the work of Shibata and Ono (1978), three components of the inclusion stress have been successfully identified and measured w functions of the applied strain. These components are the misfit stress, occurring because of differential thermal expansion effects, the inhomogeneity stress, occurring because of differences in elastic moduli, and the plasticity stress, which occurs when the matrix flows plastically around the elastic inclusion. The point at which the inclusions fracture has been identified and a calculation made of their fracture strength.