Abstract
The densification kinetics and mechanism of a low-temperature cofirable borosilicate glass (BSG) + alumina during the constrained sintering of a sandwich structure of alumina/(BSG + alumina)/alumina has been studied. The densification kinetics becomes slower when the BSG + alumina tape is constrained during firing. However, a viscous flow-controlling mechanism of the BSG also is still operative during free and constrained sintering. The densification behavior of constrained sintering can be mathematically described by free sintering, using the viscous analogy for the constitutive equations of a porous sintering glass.