Core/multi-shell Particles Based on TiH2, a High-Performance Thermally Activated Foaming Agent

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 degrees C, and the liquidus temperature of aluminium alloys is above 600 degrees 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 degrees C.