Fabrication of a Low-Cost, Lightweight Cu-AlN Composite for Thermal Management

High thermal conductivity materials with low CTE, and high strength and stiffness are required for high thermal flux applications. In addition, if these materials are relatively inexpensive, lightweight and non-toxic, and have low vapor pressure to survive in space-operating environments, they will be attractive candidates for thermal management in aerospace structures. Such materials are urgently needed for space platforms, hypervelocity vehicles and rocket propulsion systems. Under this SBIR Phase I program, MER proposes to fabricate a novel Cu-AlN composite system by a pressure infiltration casting technique in collaboration with Brooklyn Polytechnic University. Both Cu and AlN have excellent thermal conductivities (400 and 220 W/mK respectively) and the composite has the potential of achieving an optimum balance of thermal-mechanical properties, low density and low cost (<$50/lb.). Moreover, pressure infiltration casting allows for inexpensive development and production of composite materials, prototypes and net-shape components. AlN preforms with controlled porosities can be conveniently infiltrated with Cu via pressure casting with little need for additional forming or machining. With the considerable amount of expertise in AlN ceramics and Cu-based thermal management systems, MER is well-positioned to demonstrate the proof of concept during Phase I and to fabricate a Cu-AlN demonstration article for space platforms during Phase II under BMDO Jurisdiction. A lightweight, low-cost Cu-AlN composite fabricated by MER will find immediate application in aerospace systems such as space platforms, hypervelocity vehicles and rocket propulsion besides commercial applications for heat sinks, electronic packaging, avionics and power plants, internal combustion and alternative fuel engine components, energy storage devices etc