Liquid Metal & Ceramic Containment Materials
One of the critical design issues at high temperatures is the chemical compatibility between the heat transfer fluid and the containing material(s). Our research is focused specifically on the use of liquid metals as the heat transfer fluid, because their composition can be tuned to have a low melting point and many can have high boiling points above 2000°C, providing a large liquidus range. Many liquid metals also have low viscosities, comparable to water, slightly above their melting points, which allows them to pumped easily. Liquid metals can also be inexpensive, particularly when purchased in large quantities. Another unique feature of liquid metals is that they have high thermal conductivity at high temperature, arising from their high electrical conductivity. Although liquid metals are advantageous for high temperature CSP in many respects, they are generally very corrosive if contained by another metal or alloy, with a few exceptions. As a result, our focus is on the use of other refractories and ceramics. The challenge with non-metal containment materials, however, is that they may be difficult to form and join and they are most often brittle. Thus, a major undertaking in our research is the development of materials that have high corrosion resistance to the liquid metals of interest, high strength, can be easily formed into the requisite shapes and can be joined to form leak tight piping networks at such high temperatures.