metal powder injection molding process characteristics

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Comparison of metal powder injection molding technology with other processing technologies
The particle size of raw materials used in metal powder injection molding is 2-15 μ m, while that of traditional powder metallurgy is mostly 50-100 μ M. The density of metal powder injection molding is high because of the use of micro powder. Metal powder injection molding process has the advantages of traditional powder metallurgy process, and the high degree of freedom in shape is not achieved by traditional powder metallurgy.

Traditional powder metallurgy is limited to the strength and filling density of the die, and the shape is mostly two-dimensional cylinder.

In recent years, ceramic core can be used to assist in the production of slit and deep hole products. However, due to the strength of ceramic core and the limitation of the fluidity of casting liquid, there are still some technical difficulties in this process. Generally speaking, this process is more suitable for manufacturing large and medium-sized parts, while the metal powder injection molding process is more suitable for small and complex shape parts. The mechanical properties of traditional powder metallurgy process (μ m) 2-1550-100 relative density (%) 95-9880-85 product weight (g) less than or equal to 400g 10-hundreds product shape three-dimensional complex shape two-dimensional simple shape were compared.

Comparison of metal powder injection molding process and traditional powder metallurgy process die casting process is used in aluminum and zinc alloy materials with low melting point and good liquid flow. Due to the limitation of materials, the products of this technology have limitation in strength, wear resistance and corrosion resistance. Metal powder injection molding process can process more raw materials.

In recent years, the precision and complexity of precision casting technology are improved, but it still can not compare with dewaxing technology and metal powder injection molding technology. Powder forging is an important development, which has been applied to the mass production of connecting rod. But generally speaking, there are still some problems in the cost of heat treatment and the life of die in forging engineering, which need to be solved further.

The traditional machining method, which is improved by automation recently, has made great progress in effect and accuracy, but the basic program still can not be separated from the way of gradually machining (turning, planing, milling, grinding, drilling, polishing, etc.) to complete the shape of parts. The machining accuracy of machining method is much better than other machining methods, but because of the low effective utilization of materials, and the completion of its shape is limited by equipment and tools, some parts can not be completed by machining. On the contrary, metal powder injection molding can effectively use materials without restrictions. For the manufacturing of small, difficult shape precision parts, compared with machining, metal powder injection molding process has low cost and high efficiency, and has a strong competitiveness.

Metal powder injection molding technology is not competitive with traditional processing methods, but to make up for the shortcomings of traditional processing methods in technology or production. Metal powder injection molding technology can play its advantages in the field of parts made by traditional processing methods. The technical advantages of metal powder injection molding technology in parts manufacturing can form structural parts with highly complex structure.

The injection molding technology uses the injection molding machine to inject the product blank to ensure that the material is fully filled with the mold cavity, which also ensures the realization of the high complex structure of the parts. In the past, in the traditional processing technology, individual components are made first and then combined into components. When using metal powder injection molding technology, it can be considered to integrate into a complete single part, greatly reducing the steps and simplifying the processing procedures. Compared with other metal processing methods, metal powder injection molding has high dimensional accuracy, so it does not need secondary processing or only a small amount of finishing.

The injection molding process can directly form thin-walled and complex structural parts. The shape of the product is close to the requirements of the final product, and the dimensional tolerance of the parts is generally kept within ± 0.1 – ± 0.3. It is very important to reduce the machining cost of hard alloy and the loss of precious metal. The microstructure of the product is uniform, the density is high and the performance is good.

In the process of pressing, because of the friction between the die wall and the powder and between the powder and the powder, the pressure distribution is very uneven, which leads to the uneven microstructure of the pressed blank, which will cause the uneven shrinkage of the pressed P / M parts in the sintering process. Therefore, the sintering temperature has to be reduced to reduce this effect, so that the porosity of the products is large and the material is good The poor density and low density of the material seriously affect the mechanical properties of the products. On the contrary, injection molding is a kind of fluid molding process. The existence of adhesive ensures the uniform distribution of powder, which can eliminate the uneven microstructure of blank, and make the density of sintered products reach the theoretical density of the material. In general, the density of pressed products can only reach 85% of the theoretical density. The high density of the products can increase the strength and toughness, improve the ductility, conductivity and thermal conductivity, and improve the magnetic properties. High efficiency, easy to achieve mass and large-scale production.

MIM technology uses metal mold, its service life and engineering plastic injection molding tool mold is equivalent. Due to the use of metal mold, MIM is suitable for mass production of parts. Because of the use of injection molding product blanks, greatly improve the production efficiency, reduce production costs, and injection molding products consistency, repeatability, thus providing a guarantee for large-scale and large-scale industrial production. It can be used in a wide range of materials and Applications (iron base, low alloy, high speed steel, stainless steel, kevalve alloy, hard alloy).

The materials that can be used for injection molding are very extensive. In principle, any powder material that can be cast at high temperature can be made by MIM process, including the difficult to process materials and high melting point materials in the traditional manufacturing process. In addition, MIM can also study the material formula according to the user’s requirements, manufacture any combination of alloy materials, and shape the composite materials into parts. Injection molding products have been widely used in various fields of national economy and have a broad market prospect.

Vacuum Debinding Sintering Furnace