화학공학소재연구정보센터
Journal of Materials Science, Vol.35, No.4, 1037-1041, 2000
Surface strengthening and toughening of Si3N4/TiC layered composite by slip casting
Layered composite using monolithic Si3N4 as outer layers and Si3N4-15v/o TiC as inner core was fabricated by slip casting and pressureless sintering. As the composite is cooled from high sintering temperature, the difference in coefficients of thermal expansion between the constrained inner core and outer layer is expected to establish a compressive surface stress. The existence of this residual stress was verified by theoretical analysis and Vicker's indentation for the samples with various outer layer thickness. The layered composites exhibited greater strength, apparent fracture toughness and damage resistance due to the presence of compressive surface stresses in the layer.