Effects of voids at three-grain junctions on sintering and creep damage

An analysis of the growth and shrinkage rates of ellipsoidal voids on three-grain junctions is presented. The predicted rates are compared with those for cylindrical pores on the same interfaces. It is demonstrated that the sintering of ellipsoidal pores occurs more rapidly, by virtue of the increased surface curvature. The formation of such pores by the Rayleigh instability mechanism thus appears to constitute an important step in final stage sintering. Conversely, under creep loading, cylindrical voids grow at a faster rate, suggesting that creep damage develops more slowly when discrete ellipsoidal voids are maintained on three-grain junctions