Interface microstructure evolution of a novel CuW/Al composite fabricated by an infiltration method

Abstract

In the present work, a novel CuW/Al composite was fabricated using an infiltration method by designing a porous W structure on the CuW surface. The evolution and growth kinetics of interfacial intermetallics compounds (IMCs) were studied. The metallurgical reaction between the CuW alloy and Al lead to the formation of five transition zones, which were layer-like, hypereutectic, eutectic, hypoeutectic and needle-like zones from the CuW side to the Al side. Three kinds of IMCs formed at the CuW/Al interface, which were identified as AlCu, Al2Cu and Al4W based on SEM, EDS and TEM analysis. In addition, the effects of temperature (690–740 °C) and holding time (10–60 min) on interfacial microstructure were investigated. The thickness of interface increased with increasing temperature and holding time. The growth kinetics of interface obeyed linear behavior and could be expressed as: y = 3.27 × 108 exp (-163/RT)t. Ab-initio calculations showed that Al2Cu formed first because of the low formation enthalpy. The results provide a guide for controlling the interfacial microstructure and promote the engineering application of the novel composite.