Improvement in Flexural Strength of Porcelain Bodies by Applying Surface Compressive Stress

The improvement in the flexural strength of porcelain by applying surface compressive stress was investigated. Sandwich-structured slab samples were fabricated using traditional porcelain clay and composition-modified clay at a firing temperature of 1533 K. The flexural strength of the samples was measured. Preliminary results showed that the flexural strength was improved when surface compressive stress was introduced, and reduced when tensile stress was induced in the surface layer. The similarity between the thickness dependence of the flexural strength and that of surface elastic energy indicated that surface compression stress is important in reinforcing the porcelain body.