MIM manufacturing technology process characteristics and advantages

MIM manufacturing technologies are not competing with traditional processing methods, but to make up for the traditional processing method is technically inadequate or can not make the defect. MIM manufacturing technology can play to their strengths in the field of traditional processing methods on the part produced. MIM technology in the manufacture of components has the technical advantage can be shaped structural parts highly complex structures.

Injection molding technology by injection machine injection molding product blank, ensure that the material fully fill the mold cavity, thus ensuring the realization of the part of highly complex structures. In the past, traditional processing techniques made before assembly into individual components and then combined manner, in the use of MIM manufacturing technologies may be considered integrated into a complete single part, greatly reducing step, to simplify the processing procedures. Compare products size high precision MIM and other metal processing methods, you do not have to secondary processing or finishing just a few.

  

Injection molding process can be directly molded thin-walled, complex structure, product structure is close to the final product requirements, part size tolerance is generally maintained at about ± 0.1- ± 0.3. Particularly important especially difficult to reduce the machining of carbide tooling costs, reduce precious metal processing loss. Products uniform microstructure, high density, good performance

  

In the pressing process because of friction with the powder and die wall between the powder and the powder so that compacting pressure distribution is very uneven, it led to the suppression of rough uneven microstructure, which would result in the suppression of powder metallurgy uneven shrinkage during the sintering process, and therefore had to reduce the sintering temperature to reduce this effect, so that products large porosity, densification and poor, low density, seriously affect the mechanical properties of products.

Conversely injection molding process is a fluid molding process, the presence of adhesive to protect the powder evenly arranged so as to eliminate the uneven rough on the microstructure, and thus the density of the sintered products can reach the theoretical density of the material. Under normal circumstances pressing product density can only reach 85% of the theoretical density. High density products can increase strength, toughness enhanced ductility, improved electrical and thermal conductivity, magnetic properties can be improved. High efficiency, easy to achieve high-volume and large-scale production.

Increasing density of stainless steel powder metallurgy

Stainless steel commonly use smelting process. Because of its difficult cutting,  products have problem with bad accuracy, surface roughness. Thus there are still many technical problems for stainless steel manufacturing. Compared with the traditional smelting process to produce stainless steel, stainless steel by MIM manufacturing process has near net shape, high accuracy and material utilization, uniform organizational structure, etc.. It have been widely used in machinery, chemicals, shipbuilding, automotive, instrumentation and other industries.

However, the internal porosity of  MIM stainless steel greatly decreased mechanical properties, and corrosion resistance, thus severely limiting its application. Studies have shown that, by MIM manufacturing process, almost all of the properties of stainless steel are improved as the density increases. Therefore, how to increase the density of powder metallurgy stainless steel and reducing its porosity is the key issues of powder metallurgy stainless steel.

MIM manufacturing -Materials and products for automobile metal parts

Automobile metal parts are mostly made by cutting from die casting, forging, gray iron castings, copper alloy castings and malleable cast iron parts.  ZCMIM  comments.

MIM is a kind of technology that can create complex shape mechanical parts in saving materials, energy and labor way, which is quite suitable for mass production. Thus, in both United States and Japan, PM structural parts for automobiles and automotive industry are developed simultaneously. According to reports, more than 1000 kinds of automobile spare parts are made by powder metallurgy.

Car horn, radio, pocket television set, VCR, hard and soft magnetic components in instrument and meter, auto starter, electric brush in generator, electrical platinum contact (w contact) , wheel lug, exhaust valve seat for unleaded petrol engines, sintered metal oil filters for diesel engines, friction materials for heavy truck brake.

Large number of applications in DU, DX bearings and double metal bearing, and carbide cutting tools, measuring tools and molds widely used in automobile manufacturing, etc, these products or materials can only be produced by MIM. It can be said MIM manufacturing  occupies an important position in the automotive hardware accessories industry!

Performance and cost analysis of injection molded products

MIM process uses micro- fine powder, which not only can accelerate sintering shrinkage and help to improve the mechanical properties of material, extend fatigue life of material, but also improve resistance to stress corrosion and magnetic properties. For over tough materials, too hard to cut brittle materials or segregated parts with complex geometry in casting or contaminated, MIM manufacturing process can save cost greatly.

For example, a typewriter guide rod, usually it takes 14 process but only six process by MIM manufacturing process, which saves about half of the cost. When the material cost / production cost ratio increases, the potential cost will be more able to reduce. Therefore, the smaller the more complex parts, the better economic benefits will be. Through above analysis, we can see the potential of MIM molding is great.

Small complex metal parts processing knowledge

MIM manufacturer-ZCMIM was engaged in small complex metal parts manufacturing for many years and have achieved unanimous marketing support from our customers. Now let’s explain to you some knowledge for processing small complex metal parts as following.

Treatment Process

1. Corrosion and rust protection treatment: boiling black, bluing treatment also called phosphating to make metal parts with corrosion-resistant, rust-proof performance.

2, Hardening process: a method to increase the hardness of metal part. 1. increase the surface hardness of the metal parts by carburizing surface(surface color will blackish after carburizing) ; 2. hardness can be increased after quenching.

3. Vacuum heat treatment improves integrity of hardness..

Processing Craft

Machining, stamping, casting, powder metallurgy, metal injection molding, laser processing, electrical discharge machining, ultrasonic machining, electrochemical machining, particle beam processing and ultra high-speed machining, etc. Similarly,  milling, forging, casting, grinding, CNC , CNC machining centers are all belong to conventional processing.

Recent Years Trend for Injection Molding Stainless Steel

As a branch of injection molding stainless steel (http://www.zcmim.com/), stainless steel metal injection molding process has been rapid developed in past two years. Currently incomplete statistics, only in Shenzhen and Guangzhou area, there are probably more than 30 similar companies, and 80% of them are newly built for the past two years. Equipment manufacturers and feedstock manufacturers have also set up a number of outstanding domestic enterprises, providing a very good supply of equipment and raw materials, especially materials. MIM manufacturing processes breaks the situation of foreign dominance.

Stainless steel injection molding has a growing number of emerging markets. More and more companies began to try to import stainless steel injection molding process. Aerospace, automotive, medical, military, every walk of life are beginning to have production of stainless steel injection molding. China is a big country of manufacturing. The powder metallurgy process, surely will face a bigger market. Traditional processing technology will suffer one of the most serious tests.

Performance and cost analysis of injection molded products

MIM process uses micro- fine powder, which not only can accelerate sintering shrinkage and help to improve the mechanical properties of material, extend fatigue life of material, but also improve resistance to stress corrosion and magnetic properties. For over tough materials, too hard to cut brittle materials or segregated parts with complex geometry in casting or contaminated, MIM manufacturing process can save cost greatly.

For example, a typewriter guide rod, usually it takes 14 process but only six process by MIM manufacturing process, which saves about half of the cost. When the material cost / production cost ratio increases, the potential cost will be more able to reduce. Therefore, the smaller the more complex parts, the better economic benefits will be. Through above analysis, we can see the potential of MIM molding is great.

Advantage of MIM Powder Injection

Along with progress of MIM, MIM powder injection （http://www.sky-mim.com/）cost advantage will be more prominent accompanied by increased cost competition in automotive industry. So that in certain complex structural parts, such as connecting rods, camshafts, bearing caps, tooth components, closed chamber parts, components and other complex structures within the cavity, MIM powder injection substitutes for other industries.

Advantages of MIM powder injection mainly conclude as following aspects:

1. Directly forming complex geometry parts (size usually 0.1 ~ 100g);

2. Precision can up to 0.5% +/- 0.1% as spare parts, smooth surface, one-time up to Ra3.2;

3. Good interior compactness, high-density, up to 95% to 99%;

4. Uniform internal organization, no composition segregation for alloy.

5. High efficient production , substantial reduce cost for high-volume production.

6. Wide scope of materials, including refractory material, and difficult to cast material and difficult to process material.