Elasticity and Internal Friction of Polycrystalline Yttrium Oxide

Young's modulus and internal friction of polycrystalline yttrium oxide were determined from room temperature to 1658°C by sonic techniques. A linear relation was found between volume fraction porosity and Young's modulus at room temperature. The effect of porosity on room temperature internal friction is also discussed. Young's modulus decreased linearly with increasing temperature to 1000° to 1100°C, where a slight anomaly was observed accompanied by an internal friction peak. The modulus was again linear from 100° to 13500°C. Above this temperature a rapid decrease in elastic modulus occurred with a rapid increase in internal friction.