Production method of sprocket powder metallurgy material

Abstract

The invention discloses a production method of sprocket powder metallurgy material. A sprocket is made from, by weight percent, 0.2-0.3% of graphite, 0.2-0.4% of nickel, 0.8-1% of molybdenum, 0.6-0.8% of nano emery powder, 0.3-0.5% of manganese sulfide, 0.8-1% of magnesia powder, 4-7% of copper, 1-2% of modifying aid, and the balance of iron. The production method has the advantages that the modifying aid is added, ultrafine powder is added in raw mixture and can fill gaps of large particles, and accordingly apparent density of the mixture can be increased; the ultrafine powder mainly comprises nano silica and calcium stearate, the novel modifying aid is obtained from aids such as silane coupling agent, and accordingly various physical properties of the finished product, such as wear resistance, are improved further; polyethylene vinyl acetate and liquid paraffin are used as lubricants added to the modifying aid, and accordingly the effect of the modifying aid in mixing and pressing is improved; compact intensity of powder metallurgical parts can be improved greatly while compacting pressure is equal, particle combination form and pore shape of the raw materials are changed, and cracking is eliminated from an origin.

Description

technical field [0001] The invention mainly relates to a preparation method of sprocket powder metallurgy, which belongs to the field of casting. Background technique [0002] With the continuous development of my country's economy, powder metallurgy structures are used more and more widely. As a near net shape technology, powder metallurgy has great economic advantages in the production of structural parts and other parts with large batches, high dimensional accuracy and high processing costs. However, there is a weakness in powder metallurgy structural parts: the compact strength of the product before sintering is very low, which leads to cracks easily appearing during the forming and handling process, and cannot be detected during the manufacturing process. This is a fatal defect in some applications such as key parts of automobiles, which leads to the application of powder metallurgy structural parts only to low- and medium-risk stress-bearing parts, and the scope o...

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Problems solved by technology

The material composition affects the manufacturing cost, the product density has a great influence on the loss of the molding machine and the mold, and the crack is mainly affected by the strength of the compact, and it is difficult to detect