Cermet in order to make ceramics resistant to high temperature and not easy to break, people add some metal powder to the clay for making ceramics, so cermet is made. Metal-based cermets are made by adding oxide fine powder to metal matrix, also known as dispersion strengthening materials. Mainly sintered aluminum (aluminum-alumina), sintered beryllium (beryllium-beryllium oxide), TD nickel (nickel-thorium oxide) and so on. A composite material consisting of one or more ceramic phases and metal phases or alloys. Broadly speaking, cermets also include refractory compound alloys, cemented carbides and metal-bonded diamond tool materials. Ceramic phase in cermet is oxide or refractory compound with high melting point and high hardness, and metal phase is mainly transition elements (iron, cobalt, nickel, chromium, tungsten, molybdenum, etc.). ) and its alloys.