Microstructural Changes During Hot Isostatic Pressing of Sintered Lead Zirconate Titanate

Abstract

The production of dense, fine-grained ceramics is dependent on the control of both powder properties and fabrication. Although considerable effort is expended to obtain these controls, it is still difficult to consistently produce ceramics with dense, homogeneous microstructures. Efforts to gain greater control over microstructure have centered around the production of highly reactive powders with consistent properties, the utilization of densification aids during sintering, and hot pressing. An alternative approach is to utilize hot isostatic pressing as a post sintering processing technique for the removal of residual porosity in sintered ceramics. It should be understood, of course, that it is necessary for the residual porosity to exist as closed pores to be affected by pressure transmission during HIP. HIPing of sintered ceramics has been shown to yield higher densities in some ceramic systems;^1–4 however, there has been little effort to determine what happens to the microstructure during this process.