What parts are suitable for powder metallurgy processing?

What parts are suitable for powder metallurgy processing?

Compared with other processes, the cost saving advantages of powder metallurgy products are very obvious in the case of mass production. However, some parts can be processed with powder metallurgy technology, but some parts are not applicable. So what parts are suitable for powder metallurgy? Now let's learn about it with zhongwei precision editor.

Powder metallurgy processing

We start with the powder metallurgy process, because the processing technology of any powder metallurgy part is much the same. Generally, they are: product and mold design - mixing - loading, molding, press and debugging - sintering - machining or finishing - heat treatment - finishing, oil immersion - quality inspection and packaging. Some may need to be plated or blackened. Finish them well, remove the burrs, and then take them to be plated and blackened.

According to the process production route, all P/M parts shall be opened according to the size of the parts, and then tested on the machine. Generally speaking, the mold for small parts starts from 2500 yuan to tens of thousands, and the manufacturing cost of the mold is also quite high. If the quantity of a part batch is only hundreds or thousands, then the powder metallurgy process is not considered. First, the mold opening cost is high, and second, according to the size of the product, the minimum order quantity is generally at least tens of thousands. It is not cost-effective for everyone to open a mold of 5000, install the mold for a day, and make hundreds of products. Therefore, to sum up, a large number of parts are suitable for mold opening and customization, while a small number of machined parts can be obtained.

The machining tolerance of powder metallurgy parts has a variation range. In the case of no finishing, the general profile tolerance is within 3.5 ‰ and the height tolerance is within 0.15 mm. After sintering, the contour tolerance after secondary finishing and re pressing can be changed within 2.5 ‰, and the height tolerance is within 0.1mm. However, there is a limit value for both internal and external diameters. Generally, the external diameter can be as small as 0.02 mm, and the internal diameter can be as small as 0.018 mm. Therefore, if the machining accuracy is too precise, CNC machining or powder metallurgy machining should be considered.

Powder metallurgy is made by pressing iron powder, and its actual density is lower than that of related materials. Therefore, the density and strength are slightly discounted compared with the materials. If the density, heat treatment and strength of parts are required to be the same as those of materials, powder metallurgy is not suitable for processing and customization.

Powder metallurgy parts are processed by automatic molding press or injection molding machine, so too large parts are not suitable for powder metallurgy processing.