Mechanical and elastic properties of new silicon nitride ceramics produced by cold isostatic pressing and free sintering

Abstract

The mechanical and elastic properties of new silicon nitride fabricated by cold isostatic pressing and free sintering are considered. Young׳s modulus, Poisson׳s ratio and shear modulus of investigated ceramic were determined. An indentation technique for measuring the indentation modulus was developed. The flexural strength, the compressive strength and the fracture toughness were investigated. Young׳s modulus of the obtained material was 240 GPa by resonance and 214 GPa by mechanical tests. The microhardness was 1380 HV0.5 and 970 HK2.5. Obtained silicon nitride ceramic is one of a candidate material for a wide range of structural applications due to its high density (2.94 g/cm3) and low open porosity (0.1%)