In composite realm, cermets has very importantplave with its properties and applications. In here, we explain the general properties of cermets and applications that cermets are used in engineering.
Cermet is a composite material that obtained with ceramics and metals. Metals are used as matrix phase and reinforcement phase is ceramic. But if we take a look at the compositions, ceramic constitutes around 965 of whole material. Interphase bonding between ceramic and metal phases is done with relative solubility of metals and ceramics at elevated temperatures.
As you understand from its name that cermet is acronym of CERamic-METal.
There are two types of cermets; cemented carbides and oxide-based cermets.
Aluminum oxide and magnesium oxide are used as particulate phase in composite materials. In general, chromium is used as matrix metal, and other metals can be used as binders. The proportions of phases changes with the changing material and material properties. General applications of oxide-based cermets thermocouple shields, cutting tools for machining operations and mechanical seals.
It is an also another type of cermet that a carbide is used as particulate in a metal matrix. General carbides that are used in cemented carbides are titanium carbide, tungsten carbide and chromium carbide. General matrix metals are nickel and cobalt.
Cobalt is used for tungsten carbide and nickel is used as matrix material for titanium carbide and chromium carbide. Like in other cermets, the composition of matrix phase is very low compared with particulate phase, which is around 5-15%. When the particulate phase decreases, hardness also decreases but tranverse rupture strength increases.
Tungsten carbide cutting tool applications in machining operations is very common. And other applications of tungsten carbide are drill bits, mining tools, hardness test indenters, rock drilling tools. These are major applications that hardness and wear resistance is very important.
Chromium carbide material has very good corrosion resistance and chemical stability. Compared with other cemented carbides, it is much more brittle. So chromium carbide is suitable for such applications like: bearing seal rings, spray nozzles, gage blocks and vale liners.
Titanium carbides are most important material for high temperature applications when nickel is used as binder or matrix. At elecated temperatures, oxidation resistance is very important feature. In gas turbine nozzle vane production, titanium carbide materials are generally used.
These are the general properties and applications of cermets in engineering. Do not forget to leave your comments and questions about cermets below. Your precious feedbacks are very important for us.