Relationships between the properties and microstructure of Mo-Cu composites prepared by infiltrating copper into flame-sprayed porous Mo skeleton

In this paper, the porous Mo skeleton was fabricated through deposition of semi-molten Mo particles by flame spraying. The Mo-Cu composites with different Cu contents up to 68% were produced by infiltrating molten copper into porous Mo skeleton in vacuum. The microstructures of both the as-sprayed porous Mo skeletons and the as-infiltrated Mo-Cu composites were characterized. The physical and mechanical properties of Mo-Cu composite materials with different Mo constituents were investigated. The results indicate that the excellent connecting pore structure feature of sprayed Mo skeleton is beneficial to the copper infiltration and the resultant Mo-Cu composite materials exhibit high density and microhardness. Moreover, there exists a hardness gradient at the interface region between the large Mo particle and Cu matrix. The results showed that the coefficient of thermal expansion (CTE) and thermal conductivity (TC) of Mo-Cu composites increase with the copper content of the composites and the temperature. The TC data of the composites are close to the results calculated by the finite differential method by taking account of the interface structure. Moreover, the observed CTEs are in good agreement with the theoretical values calculated based on Kerner's model.