powder metallurgy

On the production site of the company, we can see the whole process of making powder metallurgy products. From powder to powder metallurgy products, we have roughly experienced four links. According to the technicians, the original production method of powder metallurgy raw materials is to file, crush or smash the solid metal into the current powder. The disadvantages of making powder like this will cause the powder to be brittle and not easy to make powder metallurgy products. The current raw materials are processed by chemical reaction to produce metal powder, such as the upstream manufacturers of the company's raw materials, It is necessary to select some chemical reactions such as scrap steel - electric arc furnace - hard water - spraying oxygen - atomization - dehydration - drying - magnetic separation - screening - homogenization, and then transport them to the warehouse of Lianyungang Dongmu New Materials Co., Ltd.

Before the company gets these metal powder processing powder metallurgy products, we initially complete the screening work in the raw material workshop. According to the technician Sun Liguang, the production process is as follows:

1. Screening and grading

First, use the sieve to divide the metal iron powder sieve into different particle size ranges, and then, uniformly mix them according to the required ratio according to the purpose, in order to ensure the gap between particles, and then select the appropriate particle size, so that the next static pressure can achieve a good density effect, because there are gaps between particles, which is the advantage of powder metallurgy products, because of these gaps, We can add lubricant in the mixing stage to make the powder metallurgy products have the function of automatic lubrication. The representative powder metallurgy parts, such as oil-bearing, rotary devices in household appliances and electric tools, need to be lubricated.

2. Mixed metal iron powder

In the process of mixing, the required metal powders are mixed together. The most commonly used powder metallurgy products are iron, carbon, copper, aluminum, nickel, molybdenum, graphite powder, etc., as well as lubricating additives to help the mixing. These substances are mechanically mixed to achieve a uniform raw material without segregation. In this process, we can add different metal powders according to the service performance of the production of powder metallurgy parts.

3. Pressing work

Put the mixed powder into the pressing mold, and use a mechanical or hydraulic press to press and form. During the pressing process, particles will move, rearrange, deform, fracture, and other processes to achieve the expected shape. Note that these pressed embryos are easy to break. After that, the technician picks up a sprocket to press the embryos, and then his hands will break them. Because these particles are mechanically connected, their strength can only meet the conditions for taking them out of the mold, so it is necessary to proceed to the next step of sintering.

4. Sintering

The sintering work is to endow the strength of the green embryo. The mesh belt sintering furnace is generally used in powder metallurgy plants. The furnace is composed of a charging platform, a pre heating zone and a high temperature heating zone, a cooling section and a unloading platform. Generally, sintering is to heat the green embryo to high temperature in a protective atmosphere or vacuum. During sintering, the combination between powder metallurgy particles is greatly improved due to solid metallurgical reaction.

Usually, we will also carry out the next step of processing after sintering, such as finishing, machining and other production processes. With the explanation of Sun Liguang, a technician of Lianyungang Dongmu New Materials Co., Ltd., we have a basic understanding of the powder metallurgy process.