In recent years, powder metallurgy technology has made breakthroughs, especially the rapid development of the automobile industry and cutting tool industry, which has driven the growth of demand for iron-based powder metallurgy products. A series of new processes and new technologies have emerged in large numbers, making the research content of the entire powder metallurgy field more in-depth. Powder metallurgy has become one of the preparation technologies for high-performance materials and mechanical parts.
So what are the types of powder metallurgy materials?
(1) Powder metallurgy high temperature materials. Including powder metallurgy superalloys, refractory metals and alloys, cermets, dispersion strengthened and fiber reinforced materials, etc. It is used to manufacture turbine discs, nozzles, blades, and other high-temperature resistant parts used under high temperature.
(2) Powder metallurgy tool and die materials. Including cemented carbide, powder metallurgy high-speed steel, etc. The latter has uniform structure, fine grains, no segregation, better toughness and wear resistance than fused cast high-speed steel, less heat treatment deformation, and longer service life. It can be used to manufacture blanks for cutting tools, molds and parts.
(3) Powder metallurgy structural materials. Also known as sintered structural materials. It can withstand loads such as tension, compression, and torsion, and can work under friction and wear conditions. Due to the existence of residual pores in the material, its ductility and impact value are lower than those of castings and forgings with the same chemical composition, which limits its application range.
(4) Powder metallurgy anti-friction materials. Also known as sintered anti-friction materials, they are made by impregnating lubricating oil in material pores or adding friction reducer or solid lubricant in material composition. The friction coefficient between the surface of the material is small, and under the condition of limited lubricating oil, they have a long service life and high reliability; under the condition of dry friction, they have self-lubricating effect by relying on the lubricant contained in itself or on the surface. They are widely used in the manufacture of bearings, supporting bushings or end face seals.
(5) Powder metallurgy porous materials. Also known as porous sintered materials, they are made of spherical or irregularly shaped metal or alloy powder through molding and sintering. The internal pores of the material are criss-crossed and inter-connected, generally with a volume porosity of 30% to 60%, and a pore diameter of 1 to 100 microns. They have good penetration performance, thermal conductivity and electrical conductivity, high temperature and low temperature resistance, thermal shock resistance, and medium corrosion resistance. They are used in the manufacture of filters, porous electrodes, fire extinguishing devices, antifreeze devices, etc.
(6) Powder metallurgy friction materials. Also known as sintered friction materials, they consist of three parts: base metal (copper, iron or other alloys), lubricating components (lead, graphite, molybdenum disulfide, etc.), and friction components (silica, asbestos, etc.). The friction coefficient is high, so they can quickly absorb kinetic energy, braking, transmission speed is fast, wear is small; high strength, high temperature resistance, good thermal conductivity; good seizure resistance, corrosion resistance, less affected by grease and moisture. They are mainly used to manufacture clutches and brakes.
(7) Powder metallurgy electromagnetic materials. Including electrical materials and magnetic materials. Among the electrical materials, powder metallurgy materials made of precious metals such as gold, silver, platinum, are used as power head materials, and powder metallurgy materials made of silver and copper with tungsten, nickel, iron, tungsten carbide, graphite, etc., are used as the matrix; Electrodes are tungsten copper, tungsten nickel copper and other powder metallurgy materials; used as electric brushes are metal-graphite powder metallurgy materials; used as electric heating alloys and thermocouples are molybdenum, tantalum, tungsten and other powder metallurgy materials.