MIM is a brand-new near-net-shape processing technology for metal parts formed by introducing modern plastic injection molding technology into the field of powder metallurgy. It is a high-tech that has developed rapidly in the field of powder metallurgy in recent years.

Introduction of MIM metal injection molding technology

The process steps of MIM are: first select the metal powder that meets the requirements of MIM and the organic binder, mix them into a uniform feed under a certain temperature condition, and use an appropriate method, and then use the injection molding machine under heating and plasticizing after granulation. Inject into the mold cavity to obtain the formed blank, then undergo degreasing treatment by chemical or solvent extraction methods, and finally obtain the final product by sintering and densification.

Introduction of MIM metal injection molding technology

Features of MIM products:

1. The geometric shape of the parts has a high degree of freedom, which can produce metal parts with complex shapes at one time, just like plastic products;

2. MIM products have uniform density and good finish. The surface roughness can reach Ra 0.80～1.6μm, and the weight range is 0.1～200g. High dimensional accuracy (±0.1%～±0.3%), generally without subsequent processing;

3. A wide range of applicable materials, wide application fields, high raw material utilization, high production automation, simple procedures, and continuous mass production;

4. The product quality is stable, the performance is reliable, the relative density of the product can reach 95% to 99%, and it can be carburized, quenched, tempered and other heat treatments. The product has high mechanical properties such as strength, hardness, elongation, good wear resistance, fatigue resistance, and uniform structure;

Introduction of MIM metal injection molding technology

Internationally, it is generally believed that the development of MIM technology will lead to a revolution in the forming and processing technology of parts and components, and it is hailed as "the hottest part forming technology in the 21st century".

MIM technical advantages:

MIM can manufacture products with complex shapes and avoid more secondary machining.

MIM products have high density, good corrosion resistance, high strength and good ductility.

MIM can combine 2 or more PM products into one MIM product, saving materials and processes.

MIM design can save material and reduce weight.

MIM can repeatedly crush and use the injected gate material without affecting product performance and high material utilization.

MIM uses molds to form complex products at one time, avoiding multiple processing procedures.

MIM can manufacture parts with complex shapes that are difficult to machine.

MIM can manufacture thin-walled products, the thinnest can be 0.2mm.

The surface roughness of MIM products is better.

MIM is more suitable for making thin blind holes and through holes.

MIM greatly reduces the workload of secondary machining.

MIM can quickly manufacture small parts in large quantities and at low cost.

Introduction of MIM metal injection molding technology

Difficulties of MIM

(1) Control the dimensional accuracy of parts

The precision of metal injection molded parts is still far behind the precision achieved by traditional powder metallurgy methods. There is still room for improvement in accuracy, mainly through fine process control, and sometimes secondary processing, such as machining, heat treatment and polishing.

(2) Reduce production costs

Use measures such as optimizing production processes, standardizing operations, and recycling waste to save costs.

Introduction of MIM metal injection molding technology

MIM future development direction

Although MIM is attracting more and more attention, its scale is still weak compared with traditional processing technology, and it has great development potential. The nascent MIM industry also requires us to adopt a series of efforts to develop industrial standards, accelerate industrialization, improve the quality of practitioners, research and develop equipment, and win customers.

(1) Multi-directional expansion of material system

Injection molding technology is ideal, can be formed economically, close to the final required shape, and requires little or no subsequent processing after sintering. In the production of precision ceramics, it is mainly applied to carbides, cermets, inorganic non-metallic ceramics, oxide ceramics, intermetallic compounds, etc.

(2) Diversification of binders and multi-channel degreasing technology

Many binder systems based on cellulose acetate, polyethylene glycol polymer, acrylic polymer, and agar have been further developed and applied. Computer-aided control thermal degreasing technology, solvent degreasing technology, catalytic degreasing technology, freeze-drying technology, microwave-assisted drying technology are all used in the degreasing research of binders.

(3) More advanced and more precise control equipment

The research of computer-precisely controlled injection molding machines and related online quality monitoring and control systems and the development of key equipment technology for computer-aided degreasing are the current and future focus directions. Forming equipment, such as powder synchronous injection molding machine, uses coordinated control double injection molding machine to produce composite parts.

(4) In the industry, a related industry chain should be formed, and the industry should be intensively cultivated

Only by thoroughly understanding technology and engineering capabilities, forming an ecological industrial chain, and clustering the industrial chain, can we resist risks and accelerate development.

Introduction of MIM metal injection molding technology

Main technical characteristics of MIM process:

1. It is suitable for the forming of various powder materials, and the product is widely used;

2. The utilization rate of raw materials is high, and the production automation is high, which is suitable for continuous mass production.

3. It can directly form small parts with complex geometric shapes (0.03g～200g);

4. The parts have high dimensional accuracy (±0.1%～±0.5%) and good surface finish (roughness 1～5μm);

5. The product has high relative density (95-100%), uniform structure and excellent performance.

Introduction of MIM metal injection molding technology