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Mix the metal powder with the lubricant until a uniform mixture is created. The mixture is then put into the mold and compacted under pressure followed by sintered compaction. Surface treatments will be applied to spare parts if necessary. The specific technological process is as follows:
Our company accepts CAD, pro-e, Solid Works and AutoCAD drawings. We will study and determine the drawings first, and then evaluate the requirements of the product, so as to complete the mold design and production. To prolong the service life of the mold, and improve the quality of the workpiece, we will choose high-quality materials such as tungsten steel in the selection of mold materials.
Mixing is to compound basic metal powder with different alloy elements in a certain proportion, adding organic solid lubricant or special additive to make a uniform powder billet. In order to achieve the mechanical, physical or chemical properties of materials, we must ensure the chemical composition of materials through strict ingredients and control.
The purpose of forming is to produce compacts with a certain shape and size, as well as a certain density and hardness. Our powder metallurgy products are filled with a powder mixture into the mold by gravity, and a pressure of 200MPa to 1500MPa is applied. The workpiece is formed in one step by the mold.
Sintering is the key process in powder metallurgy processes. The compact after molding is sintered to obtain the physical and mechanical properties as required. The compact is mainly composed of a multicomponent solid phase sintering composed of two or more components. We will sinter the product by adjusting the operating speed and chemical gas in the furnace according to the performance of different products. Sintering is generally operated at temperatures between 750 ℃and 1300℃, depending on the workpiece and the required properties.
Subsequent processing of Powder Metallurgy Products:
After sintering, subsequent processing-sizing, pore impregnation process, machining, heat treating, electroplating and so on-can be applied to the workpiece according to different needs.
Sizing
The sintered product has changed in size and shape, for which it fails to meet the size and shape required by the drawings. To correct the size and deformation, it is necessary to put the sintered body into the mold again for shaping to obtain the specified size and shape. Finished powder metallurgy parts will be more regular. Also, the dimensional tolerances will be better, and the surface finish will be improved.
Pore impregnation process
1. Impregnation: fill the pores of powder metallurgical products with chemical products.
2. Oil immersion: The oil immersed in the pores acts as a lubricant for the bearing, providing self-lubrication for the product itself.
3. Plastic impregnation or Resin impregnation: Provide sealing conditions for the workpiece. Before coating or electroplating, the workpiece is sealed by this method.
4. Copper impregnation: Also known as copper infiltration. The copper plate is pressed against the product components and the copper melts during the sintering process and penetrates into the pores of the product. Copper infiltration is used to improve the mechanical strength and toughness of low-alloy sintered steel.
Due to the limitations of the powder minding process, certain shapes such as threads, radial grooves and transverse holes are difficult to press-form, and machining can achieve it. And some parts have high-precision requirements, it is difficult to meet the requirements with the finishing method, which also needs machining. We can achieve the requirements of shape and size through machining, milling, drilling, threading, grinding, grinding, reaming, polishing and more processes.
Some burrs of powder metallurgy products appear during the compacting process and machining. Deburring is an important part of surface treatment. In addition to deburring with brushes, trowels, scrapers, etc., we also use surface finishing or shot blasting to remove burrs from bulk products, increase the surface finish of products
Cleaning is used to reduce and eliminate solid or liquid contaminants that may be contained in the workpieces.
Steam treatment can form a magnetite coating on the surface and pores of the product, which increases the compressive strength of the component and acts as sealing to increase the corrosion resistance of the product.
Heat treatment is a thermal cycle that can change the properties of material, which increases the hardness and strength of the component. Generally, there are several ways of heat treatment: quenching, case hardening, and etc.
The coating can increase the resistance to wear and corrosion. Sintered components can be treated with all conventional coatings such as galvanizing, chrome plating, nickel plating, phosphating, etc. and other special coatings.
Warehousing the finished products with package
