ABSTRACT
This chapter considers the main methods for the densification of ceramic powder compacts by conventional sintering, where sintering is performed without the application of an external pressure, and by pressure sintering, where an external pressure is applied to the sample during sintering. A key advantage of pressure sintering is the ability to significantly enhance the densification rate relative to the coarsening rate, thereby guaranteeing, in most cases, the attainment of high density and fine grain size. The densification of metal powders by hot isostatic pressing (HIP) may sometimes involve filling the loose powder into a deformable metal container, but this method is unsuitable for most ceramic powders. In conventional sintering, the main process variables are the heating cycle and the sintering atmosphere. Proper manipulation of these two variables can provide considerable benefits for densification. Applied pressure provides an additional variable that is not only effective for enhancing densification but also useful for studying the mechanisms of sintering.
