Analysis of technical requirements for powder metallurgy gear moulds
In the case where powder metallurgy materials can be used to meet the performance of the parts, when a part can be made from a sheet metal powder by a powder metallurgy gear mold, blanking must be feasible and economical. When continuous blanking is required and several pairs of molds are required, mold costs and machine usage costs are greatly increased, and it may be advantageous to use a powder metallurgy process for some parts.
When manufacturing an assembly consisting of several blanking parts, in addition to the cost of parts and molds, it is also necessary to increase the cost of assembly tools and welding. It may be appropriate to manufacture by powder metallurgy. The metal injection molding process may be an alternative forming process when the complexity of the powder metallurgy gear mold shape exceeds the manufacturing capabilities of conventional powder metallurgy processes.
Diameter and dimensional accuracy and geometrical accuracy of powder metallurgy gear molds The axial support diameter and the matching shaft diameter are important surfaces of the shaft. The diameter and dimensional accuracy is usually rT5~IV. The shape accuracy is controlled within the diameter tolerance and the shape accuracy is required. When high, the tolerances should be specified separately on the part drawing.
The surface roughness of powder metallurgy gear molds varies according to the level of precision of the machine and the speed of operation. The surface roughness requirements of shaft parts are also different. Supports the surface roughness R of the journal. The value is generally 0.16~0.63μm, and the value of the journal R. is 0.63~2.5μm