Thermal Contraction Coefficient Measurement Technique of Several Materials at Low Temperatures Using Electronic Speckle Pattern Interferometry

Abstract

Electronic speckle pattern interferometry has been applied to the measurement of the thermal expansion coefficient of a sample in the form of a plate of several commercial available metallic materials at low temperatures. Interference fringe patterns are mapping contours of constant in-plane displacement difference between two temperatures. They are dependent on the cooling rate and the temperature gradient of the specimen. The fringe separation shows the thermal strain. The temperature of specimens are simultaneously monitored using thermocouples during the cooling process. Analysis of the thermal strains and temperatures allows for the measurement of the thermal expansion of the specimen.