Metal Powder Injection Molding Furnace

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Metal powder injection moulding furnace is the product of the infiltration and intersection of many disciplines such as plastic moulding technology, polymer chemistry, powder metallurgy technology and metal materials. By using injection moulds, billets can be moulded and high-density, high-precision, three-dimensional complex shape structural parts can be rapidly and accurately manufactured through sintering, which can materialize design ideas into certain structures. It is a new change in the manufacturing technology industry that functional products can be produced directly in batches. This process technology not only has the advantages of fewer conventional P/M processes, no cutting or less cutting, and higher economic benefits, but also overcomes the shortcomings of traditional P/M process products such as low density, uneven material quality, low mechanical performance, difficult to form thin wall and complex structure. It is especially suitable for mass production of small, complex and metal parts with special requirements.

COMPARISON BETWEEN METAL POWDER INJECTION MOLDING AND TRADITIONAL POWDER METALLURGY
The particle size of raw materials used in metal powder injection moulding is 2-15μm, while that of traditional powder metallurgy is mostly 50-100μm. Metal powder injection moulding process has a high density of finished products due to the use of fine powder. The high degree of freedom in shape can not be achieved by traditional powder metallurgy.

COMPARISON BETWEEN METAL POWDER INJECTION MOLDING AND PRECISION CASTING
In metal forming process, die casting and precision casting can form three-dimensional parts with complex shapes, but die casting is limited to low melting point metals, while precision casting is limited to high melting point metals such as alloy steel, stainless steel, superalloy and non-ferrous metals, but is powerless to refractory alloys such as cemented carbide, high density alloy, cermet, which is the essential limitation of precision casting. Moreover, precision casting is very difficult or not feasible for the production of small, thin and large-scale parts. The industrialization of precision casting has matured and its development potential is limited. Metal powder injection moulding is a new technology, which will be squeezed into the market of large quantities of small parts in precision casting.

COMPARISON BETWEEN METAL POWDER INJECTION MOLDING AND TRADITIONAL MACHINING
The traditional mechanical processing method has recently improved its processing ability by automation. It has made great progress in efficiency and accuracy. However, the basic program still needs the way of gradual processing (turning, planer, milling, grinding, drilling, polishing, etc.) to complete the shape of parts. Machining method is far more accurate than other processing methods, but because the effective utilization of materials is low, and the completion of its shape is limited by equipment and tools, some parts can not be machined. On the contrary, metal powder injection molding can effectively utilize materials, and the degree of freedom of shape is not limited. Compared with mechanical processing, metal powder injection moulding process has lower cost, higher efficiency and strong competitiveness for the manufacture of small and high-difficulty shape precision parts.
Metal powder injection moulding technology makes up for the shortcomings of traditional processing methods in technology or can not be produced. It is not only competing with traditional processing methods. Metal powder injection moulding technology can play its advantages in the field of parts that can not be produced by traditional processing methods.

Advantages of Metal Powder Injection Molding
From the analysis of the process essence of metal powder injection moulding, it is the most suitable process for mass production of high melting point materials, high strength and complex shape parts. Its advantages can be summarized as follows:
(1) Metal powder injection moulding can form various metal parts with complex three-dimensional shape (as long as the material can be made into fine powder). The density and performance of each part are identical and isotropic. It provides a greater degree of freedom for part design.
(2) Metal powder injection moulding can maximize the production of parts close to the final shape, with high dimensional accuracy.
(3) Even in solid state sintering, the relative density of metal powder injection moulding products can reach more than 95%, and its performance can be comparable to that of forging materials. In particular, the dynamic performance is excellent.
(4) The price of powder metallurgy automatic moulding machine is several times higher than that of injection moulding machine. Metal powder injection molding can easily adopt a multi cavity mold with high molding efficiency and long service life. It is convenient and quick to change and adjust the die.
(5) Injection material can be used repeatedly, and the material utilization rate is over 98%.
(6) Fast product turning. The production flexibility is great, and the time from design to commissioning of new products is short.
(7) Metal powder injection moulding is especially suitable for mass production and has good consistency in product performance. If the parts produced are selected properly and the quantity is large, higher economic benefits can be obtained.
(8) Metal powder injection moulding has a wide range of materials and wide application fields. The materials used for injection moulding are very wide, such as carbon steel, alloy steel, tool steel, refractory alloy, cemented carbide, high specific gravity alloy, etc. The application field of metal powder injection moulding products has already spread all over the national economy.

The choice of metal forming process, the complexity of parts and production output are two main determinants. Metal powder injection moulding (MPIM) technology has a predominant advantage when the production of parts is large and the complexity is high. For the part designer, we should focus on the design of parts with complex three-dimensional shape and large production capacity, so as to give full play to the characteristics of metal powder injection moulding process, and achieve the effect of reducing production costs and improving product performance.

Material Performance and Cost Analysis of Injection Molded Products
Micron-sized fine powder used in metal powder injection moulding process can accelerate sintering shrinkage, help to improve the mechanical properties of materials, prolong the fatigue life of materials, and improve wear resistance, stress corrosion resistance and magnetic properties. The main suitable materials for metal powder injection molding are: Fe alloy, Fe-Ni alloy, stainless steel, W alloy, Ti alloy, Si-Fe alloy, cemented carbide, permanent magnet alloy, alumina, silicon nitride, zirconia and other ceramic materials.

For over-hard, over-brittle and difficult-to-cut materials or parts with complex geometry and segregation or contamination of raw materials in casting, the use of metal powder injection moulding technology can greatly save costs. When the ratio of material cost to manufacturing cost increases, the potential cost can be reduced more, so the smaller and more complex the parts, the better the economic benefit will be. Through the above analysis, we can see that metal powder injection molding has great potential.

Application fields of metal powder injection moulding technology:
1. Automotive parts: airbag parts, car lock parts, seat belt parts, car door lifting system, pinion, car air-conditioning system parts, rack in brake system, etc., small parts of sensors in fuel supply system;
2. Military parts: gun parts, ammunition parts, fuze parts;
3. Computer and IT industries: such as printer parts, magnetic cores, pin pins, driving parts, optical communication ceramic plugs;
4. Tools: such as drills, cutters, nozzles, spiral milling cutters, pneumatic tools, parts for fishing gear, etc.
5. Household appliances: such as watch case, watch chain, electric toothbrush, scissors, golf ball head, jewelry chain, blade knife head and other parts;
6. Medical machinery parts: such as orthodontic frame, scissors, tweezers;
7. Electrical parts: micro motors, sensors;
8. Machinery parts: such as textile machine, edge-winding machine, office machinery parts, etc.