The ultrasonic wave reflection method has been used to determine the elastic constants, Young's modulus, shear modulus, and Poisson's ratio of various steels and aluminium alloys in the temperature range from room temperature to 800°C. It was found that the both elastic moduli tend to decrease with the rise of temperature. Poisson's ratio, however, shows no significant difference among the materials with temperature and there is a slight increase with rise of temperature. The data were successfully represented by the empirical formulae in the form of exponential function of temperature. They are very convenient expressions for the analyses of thermal stress problems.
