Refractory Materials
Refractory materials are materials that are designed to withstand high temperatures, typically over 1500 °C, and often have a service temperature higher than 2000 °C. Refractory materials are heterogeneous materials composed of oxides or carbides of metals in combination with other compounds. They are essential for any application involving high temperatures and extreme environments such as industrial heating and combustion chambers.
Refractory materials can be classified into two broad families based on their usage, namely refractory metals and refractory ceramics. Refractory metals are further classified into refractory alloys and pure refractory metals depending on the composition of the parent material. Refractory ceramics include a wide range of materials such as brick, monolithic refractories, castables, and insulation materials.
Refractory alloys are composed of a combination of refractory metals, such as titanium, zirconium, hafnium, and niobium, and other metals, such as nickel and molybdenum. Refractory alloys exhibit a wide range of properties and can be fabricated into a variety of components for demanding applications. They are mainly used for engineering components and components in process plants exposed to high temperatures, such as furnace and boiler linings, spark plugs, turbine components, and reaction vessels.
Refractory ceramics are mainly composed of alumina, silica, and zirconia, either pure or in combination with other materials. They can be shaped into components via processes such as pressing and sintering, casting, and ramming or extrusion. Refractory bricks are made from alumina, silica and other compounds, such as magnesium oxide. They are mainly used as linings for furnaces and incinerators, and have a high temperature resistance, high compressive strength, low thermal conductivity, and low thermal expansion. Monolithic refractories are composed of a combination of refractory aggregates held together by a bonding agent. Monolithics are mainly used as linings for kilns, furnaces, and the interior walls of metal casting furnaces.
Castable refractory materials are a type of monolithic refractory, but are pre-mixed in dry form and can be easily transported and cast into desired shapes. They are mainly used in the construction of incinerator, ovens, and reactors. Ceramic fibers are made from alumina, silica, magnesia, and zirconia, either pure or in combination with other materials. They are mainly used as insulation in furnaces, boilers, and reactors, and have a low thermal conductivity, low thermal expansion, and are lightweight.
Insulation materials are mainly composed of alumina, silica, and magnesium oxide, either pure or in combination with other materials. They are mainly used as high temperature insulation, such as in boilers, furnaces, and reactors, and have a low thermal conductivity, low thermal expansion, and are lightweight.
In conclusion, refractory materials are essential for any application involving high temperatures and extreme environments. They can be classified into two broad families based on their usage, namely refractory metals and refractory ceramics. Refractory metals are further classified into refractory alloys and pure refractory metals and refractory ceramics includes a wide range of materials such as brick, monolithic refractories, castables, ceramic fibers, and insulation materials.
