Design of competitive light-weight composite materials: SiC/TiSi2
Light, stiff and strong materials capable of bearing load have become increasingly valuable for the design, construction and assembling of lightweight transportation systems such as aircraft, high-speed trains or even for the construction of satellites. In spite of the need, there are few promising new materials in current development that are suited for advanced applications. It is not surprising that R&D is highly focused on advanced ceramics and composites, i.e. MMC-type where the metal
... here the metal phase is an Al, Si or Ti-based alloy. To produce SiC-based composites with desirable properties, the reactive infiltration process has well known advantages over other conventional processing techniques. These processing routes have particular advantages over classical sintering and hot pressing techniques, i.e. lower processing temperatures, shorter times and near-net shape fabrication capabilities. However, many aspects are still not fully understood mainly related to the interfacial phenomena occuring during infiltration process. Currently, three are the greatest open challenges for scientists: theoretical description of the process by computational models, decrease or replacement of the unreacted Si, and finally, the possibility to "control" the "pore closure" phenomenon. A key contribution could be coming from know-how on wetting characteristics, reactivity, surface properties and thermodynamics concerning reacting phases . Systematic investigations of wetting characteristics, reactivity, surface properties and thermodynamics concerning Si-Ti/C-based substrate couple have been carried out. In addition, infiltration experiments have been performed between Si-Ti/C-preform with different porosity. All the collected findings will be detailed in a next paper. In this work, the more relevant results obtained by wetting tests will be reported and briefly discussed.