For many years, new techniques have been developed to overcome the problems involved with the generation and detection of ultrasound in materials at high temperature [1,2]. A non-contacting technique is described using lasers to generate and detect ultrasound and which can be used to study the variation in acoustic velocity as a function of temperature. Results are presented for the change in longitudinal velocity (vℓ) with increasing temperature in five polycrystalline materials, namely Dural, aluminum, AISI-310 stainless steel, iron and graphite
