Thermal Conductivity of Intermetallic Compounds with Metallic Bonding

Abstract

Thermal conductivity is one of the key parameters required for high-temperature structural applications of metallic materials. In this overview, the thermal conductivity of intermetallic compounds are extensively described based mainly on our past works, since there had been less works in this research field. Emphasis is placed on the B2 and the L1₂ compounds with metallic bonding such as NiAl, Ni₃Al, etc., which have been attracting attention for engineering applications at higher temperatures. The thermal conductivity data have been accumulated for the intermetallic compounds, and the phenomenological aspects are reviewed in detail as a function of alloy composition, constituent and temperature. The Wiedemann-Franz law is applicable to the intermetallic compounds, indicating that the carrier of thermal conduction is an electron rather than a phonon. The thermal conductivity of an intermetallic compound with the ordered crystal structure is characterized as an enhancement due to ordering with reference to the basic contribution of solid solution with the disordered crystal structure. It is demonstrated that the thermal conductivity of intermetallic compounds is reduced by the addition of a third element, and this subject is also covered.