多結晶セラミックスの粒界すべりに関するレオロジー

クリープと応力緩和

抄録

The grain-boundary sliding and interlocking of polycrystalline ceramics are investigated by means of the model arrays, i.e., two-dimensional arrays of square or hexagonal elastic grains embedded in a contiguous grain-boundary melt. A nonlinear Maxwell type constitutive equation is derived in an universal manner by considering two fundamental processes associated with elastic deformation of grains and squeezing-in/out of a viscous fluid between adjacent grains. The equation applied to creep deformation and stress relaxation yields several important predictions for the nonlinear viscoelastic behavior of polycrystalline ceramics with grain-boundary phase.