There are many types of gears in production, including sun gear, straight gear, double gear, internal gear, external gear, and bevel gear.
The production of powder metallurgy gears must first confirm the materials. There are many medium standards for powder metallurgy materials. As Japan, the United States and Germany are leading the world in powder metallurgy research, there are currently a wide range of materials for JIS, MPIF, and DIN material standards.
Gears usually have certain requirements for strength, so the performance of the selected materials must meet the product requirements. At present, the more widely used materials for gears are Fe-Cu-C-Ci materials (compliant with JIS SMF5030, SMF5040, and MPIF FN-0205, FN-0205-80HT standard) Fe-Cu-C materials are also available.
The density of powder metallurgy gears, because the gears are used for transmission, have higher requirements for the strength of the gears, so the density of the products will be relatively high, and the tooth resistance will be improved and the strength will be higher.
The hardness of powder metallurgy gears is closely related to the material, density grade and post-processing of the product. So when you purchase gears, the hardness range must be indicated in the drawing.
After the gear is sintered, in order to improve the strength and wear resistance of the gear, post-processing procedures are usually added to improve performance. There are usually two treatment processes:
1. Surface water vapor treatment. Water vapor reacts with Fe on the surface of the gear to form a dense substance Fe₃O₄. Fe₃O₄ has a higher hardness, which can increase the wear resistance and surface hardness of the gear.
2. Carburizing treatment
The same as the carburizing treatment of ordinary machined gears, carbonitriding and quenching are used in many cases to improve the surface hardness of the gears.