Thermal Expansion Coefficient and Young’s Modulus of Hydrogenated fcc Fe–Ni Invar Alloys

Abstract

Thermal expansion coefficient and Young’s modulus of hydrogenated fcc Fe–Ni Invar alloys have been measured as a function of temperature and hydrogen concentration. Anomalous behaviour in thermal expansion and Young’s modulus of the Invar alloys was faded with hydrogenation. This change corresponds to the disappearance of the characteristic weak ferromagnetic states of Fe–Ni Invar alloys, which was previously investigated by means of Mössbauer effect. The experimental results of thermal expansion, Young’s modulus and Mössbauer effect was interpreted on the basis of the electron theory.