Theoretical approach to local and effective properties of BMG based matrix-inclusion nanocomposites

Expressions for the effective elastic constants and the effective thermal conductivity of nanocomposite materials are derived. The considered systems are described as a matrix with embedded nanometre scale particles. The peculiarity of the nanoscale is taken into account defining an interphase between particle and matrix as a third phase with different properties which is supported by computer simulations. The theoretical treatment is based on the classical composite sphere assemblage model which is extended to matrix-inclusion-interphase systems. The results quantify the interplay of local and effective properties of nanocomposite materials and establish geometry mediated relations between elastic and thermal properties. The method is applied to hypothetical bulk metallic glass (BMG) nanocomposites generated from known monolithic BMGs. It is shown that the interphase has significant impact on the effective properties of BMG based nanocomposites. Cross property relations between the ratio of shear and bulk modulus on the one hand and the thermal conductivity on the other hand show that different plastic behaviour of BMGs can be discussed in terms of the presented theoretical results.