Refractory alloys for concentrated solar power

Concentrated solar power, or thermal solar, have the potential to produce large amounts of electricity offering a sustainable solution to generating power. A field of mirrors focusses light from the sun onto a receiver, which transfers the heat to a transfer fluid enabling electricity to be generated as in conventional power plants. However, the receiver experiences harsh conditions: high temperatures, sudden heat flux variations, oxidation and contact with the heat transfer fluid.

Various materials are being considered as potential materials for the thermal receiver. Among them are multi-principle element refractory alloys, comprising of combinations of Al, Cr, Mo, Ta, Ti, V, W and Zr, are being considered as novel high temperature materials and have demonstrated reasonable corrosion resistance with some of the heat transfer fluids. The microstructures of refractory multi-principle element alloys can contain multiple phases, and evolve during high temperature thermal exposure. To determine whether these alloys are suitable for use in concentrated solar power receivers, understanding of their microstructural stability, corrosion performance and optical properties will be crucial.

In this project, the potential refractory alloys will be selected and the key properties for use in thermal solar applications assessed. Electron microscopy and X-ray diffraction will be used to determine how their microstructures evolve when subjected to the high temperatures experience in service, and mechanical, corrosion and optical properties assessed.