Investigation on the densification behavior of Mo-Cu composites regulated by in situ growth of Mo ₂ C induced by infiltration

Abstract Mo-Cu composites are indispensable in applications such as aerospace thermal management and high-power electronic packaging due to their tunable thermal expansion coefficient and high thermal conductivity. However, their inherent immiscibility leads to poor densification in traditional preparation processes, limiting their engineering applications. This study aims to address this challenge through an interface engineering strategy. We propose a novel in situ carbide interface engineering approach: using high-carbon-yield phenolic resin as a binder and carbon source, which is coated onto molybdenum powder via ball milling. Subsequently, during the pressureless infiltration process at temperatures ranging from 1150 °C to 1350 °C, nano-sized Mo ₂ C is in situ formed at the Mo/Cu interface. The results demonstrate that the in situ generated Mo ₂ C significantly enhances wettability and promotes densification. Under the optimized process at 1300 °C, the material achieves the best comprehensive properties: a relative density of 98.4%, a hardness of 185.1 HV, and an electrical conductivity of 38.4% IACS (only a 3% decrease compared to the sample without Mo ₂ C addition). This work confirms that precise control of the interface composition via in situ synthesis technology enables the synergistic optimization of densification and functional properties in immiscible Mo-Cu systems, providing an effective approach for developing high-performance composites.