Room-Temperature Densification Technique of Bulk Ceramics and Its Applications

The bulk ceramics with high functionality and reliability are not possible without microstructure morphology control. Since sintering is the phenomenon of forming physical bonds at the contact points of particles, the particle-assembled structure before densification is the basis of microstructure morphology and a process factor that must be controlled. The application of a high isotropic pressure of 1000 MPa not only improves the homogeneity and filling of the particle-assembled structure, but also increases the chemical potential, and promotes the dissolution of solid particles into the solvent without heating. This paper outlines a technology for densifying bulk ceramics at room temperature based on the control of the particle-assembled structure (Reaction Sintering with Cold Isostatic Press: RS-CIP). As an example of the application of this technique, fluorescent materials composed of nitride phosphor particles and a MgO matrix are also introduced.