US Egypt Cooperative Research: Development of High Performance Nano-Sized Tungsten Heavy Alloy Composites by Powder Metallurgy

San Diego State University Foundation, San Diego CA

Investigators

Abstract

This collaborative research project is being undertaken by Dr. Randall M. German, San Diego State University, and Dr. Sayed Farag Moustafa, Central Metallurgical Research and Development Institute of Egypt, on the topic of utilizing new nanoscale coating techniques to form copper coated nanoscale tungsten powders for low temperature net-shape sintering densification. Tungsten heavy alloys (WHAs) were developed in the 1930s for applications requiring high density and tailored thermal and electrical properties useful in electrical switching equipment, inertial guidance systems, and vibration dampening. Today, new applications are emerging in computer and microelectronic systems for heat dissipation, as well as in electro-discharge machining and aircraft stabilizers. Many WHA compositions rely on high tungsten contents and a matrix consisting of various iron, nickel, cobalt, and copper additions. Tungsten solubility in the matrix is historically required to induce liquid phase sintering densification. Concomitant with densification (at temperatures near 1500°C) is extensive grain growth. However, an alternative is to use an insoluble system, W-Cu, with a nano-sized particle to induce rapid, lower temperature sintering without grain coarsening. In this collaboration, a wide range of scientific and engineering applications will be explored, including microwave packaging, electrical contacts, integrated circuit heat sinks, welding electrodes, and plasma spray electrodes. The US partner will be responsible for sintering and coarsening studies on the novel powders fabricated by the Egyptian partner, who will also work on rationalization of the properties and applications. The project is funded under the US-Egypt Joint Fund Program, which provides grants to scientists and engineers in both countries to undertake cooperative research.