New theoretical equation for effective thermal conductivity of two-phase composite materials

Abstract

A new theoretical equation that describes the thermal conductivity of a two-phase composite is proposed. The Cheng–Vachon equation has been modified, and a new parameter, i.e. the modified volume fraction, is introduced. The modified volume fraction is a function of the physical volume fraction and thermal conductivity ratio of constituent phases. It was found that the new equation can describe the thermal conductivity of different two-phase composites, such as Cu/solder, Al/water, Al/air and cellular concrete, very accurately.