Explanation

A binary carbon (nitrogen) compound with a quasi layered structure, with the general chemical formula M_ N+1AX_ n. M represents transition metal elements, A represents III A or VA group elements, and X represents carbon, nitrogen, or their combination. The n-value of these compounds is usually between 1 and 3, but the maximum can reach 6. These compounds were first proposed in the 1960s and included the concept of ternary transition metal carbide or nitride for the first time. Subsequently, people gradually discovered some compounds with similar structures, such as Ti3SiC2, Ti3GeC2, and Ti3AlC2. In 2000, Barsoum referred to this kind of materials as "M_n+1AX_n" phase, usually abbreviated as MAX phase. MAX phase ceramics can be prepared by in-phase reaction or chemical vapor phase deposition. These materials have a series of outstanding characteristics, including good conductivity and thermal conductivity at room temperature, relatively low hardness, high elastic modulus and shear modulus, easy machining, high yield strength, excellent thermal stability and oxidation resistance. Therefore, they are widely used in high temperature structural materials, high temperature heating materials, electrode brush materials, chemical anti-corrosion materials and other fields.

Classification