Assessment of Strength by Young's Modulus and Porosity: A Critical Evaluation

Literature data on strength, porosity, and Young's modulus at room temperature of reaction-bonded silicon nitride, sintered silicon nitride, and hot-pressed silicon nitride have been fitted into available and proposed strength-porosity relationships. In general, the Lewis method of iterative least-squares fitting in these relationships has been found to be better than conventional linearized least-squares fitting. Further a semiempirically proposed strength–Young's modulus relationship has been found to predict strength more precisely than the conventional strength-porosity relationship.