The flow characteristics of hot-pressing of beta-Al₂O₃

The Murray's plastic flow equation of hot-pressing was solved using the methods of progressive approximation and direct integration. In the solution, ln [1/(1 - 0)] (0 = relative density) is expressed as a function of the hot-pressing time (t), in an approximate form of power series and in a precise form of an exponential function or an infinite power series. The solution can be used to describe the hotpressing behavior of Beta-Al₂O₃. Within the temperature and pressure range used, the powder parameters, such as surface tension γ, yield stress f, and viscosity η, were calculated or estimated and used to rationally explain the effect of the chemical composition on the hot-pressing behavior.