High-temperature young modulus of reaction-bonded Si3N4, liquid-phase sintered SI3N4 and sialon

Temperature dependence (RT-1400 C) of Young's modulus and strength of reaction-bonded silicon nitride (RBSN), liquid phase sintered silicon nitride (LPSSN) and Sialon has been investigated. Although strength and Young's modulus are related through the equation σ = 7.39 × 10−6E1.41 the influence of temperature on strength and Young's modulus is different. For RBSN strength increases with temperature, reaches a maximum at 1200 C and then decreases. But Young's modulus steadily decreases with temperature. For LPSSN and Sialon both Young's modulus and strength degrade with temperature. Details of Young's modulus data have been presented and their implication in assessing temperature dependence of strength discussed