Core/multi-shell particles based on TiH2, a high-performance thermally activated foaming agent

Abstract The key element in the production of metal foams is the availability of a gas provider, which must be able to release the gas once the metal reaches the liquidus temperature, allowing the homogeneous formation of pores in a narrow size distribution. TiH2 is by far the most widely used foaming agent for aluminium alloy foaming; however, this compound starts to release hydrogen during heating below 450 °C, and the liquidus temperature of aluminium alloys is above 600 °C. In this work we studied the formation of a core/shell structure based on TiH2 particles. The best results were obtained with a TiH2/Ti3O@TiO2/SiO2 core/multi-shell structure, which starts to release hydrogen around 600 °C.