Mechanisms Involved in Securing Dense, Vitrified Ceramics from Preshaped Partly Crystalline Bodies

The internal porosity of ceramics shaped before fusion has been improved by three firing techniques: (1) firing in vacuo , (2) firing in diffusible gas, and (3) finish firing and cooling under pressure. A method of measuring pore volume and texture has contributed to understanding the operating mechanics of these processes. This has led to recognition of the firing‐process requirements for different porcelains depending on their crystalline content, matured viscosity, service conditions, and performance specifications.