Abstract
The improvement of the flexural strength of the Porcelain by applying the surface compressive stress was investigated. Porcelain clay of which thermal expansion was adjusted appropriately was prepared from original clay. This clay was attached on the surface of slab made from original clay for various thickness and these slab samples were fired at around 1260C, which was the standard firing temperature for original clay. The flexural strength and thermal expansion were measured. The distribution of the strain in the surface layer and inner slab was determined from the electrical resistance of Platinum wires in the slab. When the thickness of the surface layer was comparable with the inner slab, we obtained that flexural strength was 20 % stronger than original slab when thermal expansion of inner slab was about twice as large as that of surface layer. The flexural strength and inner stress will be discussed.
