Good graphite is dense to the naked eye. The materials of the end face seal friction pair. The resin-impregnated graphite has good corrosion resistance, but not high temperature resistance (temperature resistance is about 170~200℃); the impregnated metal graphite has good high temperature resistance (the high temperature resistance of bronze, aluminum, lead, etc.

Tungsten carbide alloy The metal carbides with high hardness and high melting point, such as tungsten carbide and titanium carbide, are pressed and sintered by powder metallurgy with a binder. Impregnated graphite can be divided into two types: resin impregnated and impregnated metal. Tungsten carbide is the most widely used end face seal material, and seal seamless belt is mostly used as a static ring for medium and low speed mechanical seals and a moving ring for high-speed mechanical seals.

The material of the auxiliary sealing ring. The advantages are high hardness and strength, wear resistance, high temperature resistance, corrosion resistance, low linear expansion coefficient, and the disadvantages are brittleness and difficult processing. It is used as a moving ring for medium and low speed mechanical seals and a static ring for high-speed mechanical seals.

The sealing performance and service life of the mechanical seal are related to the materials of each part, especially the material of the end face seal (friction pair), the material of the auxiliary seal and the material of the spring. Most applications are alumina ceramics and cermets. Graphite is the most widely used non-metallic material. Ceramics are mostly used in corrosive media, medium and low speed occasions. can reach 400~500℃), but the corrosion resistance is poor .

Surfacing hard alloy hard alloy surfacing welding hard alloy on the sealing surface of carbon steel, chromium steel and chromium nickel steel, the advantages are high hardness, good wear resistance, good temperature resistance (below 500 ℃), corrosion resistance or Good cavitation, the disadvantage is that it is easy to produce pores, slag inclusion and uneven surface hardness. The disadvantages are brittleness and high hardness that are difficult to process.