The effect of coherency strain energy on chemically induced liquid film migration (CILM) has been studied. The coherency strain energy arises from the difference in equilibrium lattice parameter between coherent diffusion layer formed at the front of the retreating grain and the inner part of the grain. The coherency strain energy in a liquid phase sintered Mo-Ni alloy was varied by both changing sintering temperature and adding W as a third element. The CILM occured when the coherency strain energy existed regardless of the sign of the difference of equilibrium lattice parameter being positive or negative. The CILM did not occur, when the decrease in lattice parameter of coherent diffusion layer by raising resintering temperature was canceled out by the increase in lattice parameter by alloying W, which results in reduction in the chemical free energy. This result shows that the coherency strain energy is responsible for CILM in good agreement with Hillert's suggestion.
