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

这一合作研究项目由圣地亚哥州立大学的兰德尔·M·德意志博士和埃及中央冶金研究开发研究所的赛义德·法拉格·穆斯塔法博士共同开展，主题是利用新的纳米级涂层技术来形成用于低温网状烧结致密化的铜包覆纳米钨粉。钨重合金(WHAS)是在20世纪30年代开发的，用于要求高密度和量身定制的热和电性能的应用，用于电气开关设备、惯性制导系统和减振。如今，用于散热的计算机和微电子系统以及电火花加工和飞机稳定器的新应用不断涌现。许多WHA成分依赖于高钨含量和由各种铁、镍、钴和铜添加组成的基质。钨在基质中的溶解度历来是诱导液态烧结致密化所必需的。伴随着致密化(在1500°C附近)的是广泛的颗粒生长。然而，另一种选择是使用含有纳米颗粒的不溶体系W-Cu来诱导快速、较低温度的烧结，而不会粗化颗粒。在这项合作中，将探索广泛的科学和工程应用，包括微波封装、电接触、集成电路散热器、焊接电极和等离子喷涂电极。美国合作伙伴将负责对埃及合作伙伴制造的新型粉末进行烧结和粗化研究，埃及合作伙伴还将致力于性能和应用的合理化。该项目由美国-埃及联合基金计划资助，该计划向两国的科学家和工程师提供赠款，以开展合作研究。

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.