MIM Metal Injection Molding Parts

Which one is better for MIM metal injection molding

There are too many P/M manufacturers, but there are only a few large P/M manufacturers. For the purchasing staff of some companies, small companies tend to focus on price, and the cooperative price and stability between large companies are also the goal.

For the current market situation, the price of iron powder is unstable, rising from 6000 last year to 8-9000. Even if the price rises, it is difficult for people with money to buy iron powder. If this situation occurs in the powder metallurgy factory, the supply is not available, even if the lowest price, the purchaser will not cooperate with it. In the face of the shortage of iron powder in major iron and steel plants, the first thing is to maintain the supply of large customers, so it is normal for small customers to have money but cannot buy iron powder. Lianyungang Dongmu New Materials Co., Ltd. has met many customers who come to inquire about the price, and the products are all powder metallurgy products that have been mass produced before. The development of secondary supply is due to the lack of product supply. As the operating cost of a small enterprise is much lower than that of a large factory, it will have a great advantage in terms of price, but it is slightly less than that of a large factory in terms of quality and assurance. If the enterprise loses because of the quality problem of powder metallurgy products, it is difficult for small powder metallurgy manufacturers to repay. In the case of similar prices, many enterprises will choose appropriate powder metallurgy manufacturers to cooperate.

PM compaction and powder injection molding are common in powder metallurgy. Today, I would like to share with you about powder injection molding.

PIM is composed of metal powder injection molding (MIM) and ceramic powder injection molding (CIM). It is a new part processing technology that introduces plastic injection molding technology into the field of powder metallurgy. Plastic products in daily life are necessities with complex shapes and low prices. Because of their low strength, they can only be used as toiletries, gloves, etc. Therefore, in order to improve the performance, metal and ceramic powders are added to the plastics to obtain powder metallurgy products with higher strength and good wear resistance. For many years, powder metallurgy manufacturers have been improving the density of solid particles in powder injection molding to a large extent.

In Lianyungang Dongmu New Materials Co., Ltd., it is a powder metallurgy manufacturer with PM and MIM injection molding technologies. The 1 billion yuan invested in 2021 to expand the MIM injection molding workshop will be put into full use in September this year. It is mainly to mix the metal powder and adhesive evenly at a certain temperature to make the feed, obtain the blank after injection molding, and burn the final MIM injection molding powder metallurgy parts after degreasing. There are many characteristics of the finished MIM injection molding parts.

1. Like plastic injection molding, parts can be made with very high degree of freedom of geometric shape, which is used for small parts with high requirements on density distribution, size and accuracy. Because the price of raw materials is conventional and the price of powder metallurgy is expensive, for the sake of production cost, the parts usually produced are about 2-200g, but the MIM injection molding technology itself has no size limit.

2. Alloying has good flexibility, which can save costs for parts that are too hard, brittle, difficult to cut, polluted, and expensive raw materials.

3. The selection of materials is very wide, and the utilization rate of raw materials is high. It is suitable for low alloy steel, stainless steel, high-speed steel, copper base alloy, ceramics, high ratio tungsten alloy, die steel, etc. Due to the different properties of injection molded parts, if appropriate metal components are added, the pollution in production will be much less than that in other processes.

4. High degree of automation, simple process, and continuous large-scale production of injection molded parts. MIM injection molding is produced by using molds, and the subsequent parts produced rarely need machining, reducing the subsequent processing technology. At the same time, the consistency comparison and repeatability of products are greatly guaranteed. MIM injection molding can realize multiple cavities in one mold, and can produce multiple injection molding parts blanks at one time to improve efficiency and reduce cost.

5. MIM injection molding products have high quality stability and reliable performance. Compared with powder metallurgy pressing, the density distribution of parts is uniform, which can reach 95% - 98%. The subsequent work can be decarburized, heat treated, tempered, etc. with the use performance of parts, which is the same as the subsequent process of powder metallurgy pressing.

6. It is important to compare with other processes, such as machining, precision casting and powder metallurgy pressing. The internal structure of MIM injection molded parts is more uniform, with precision, smooth surface, and high mechanical properties of density, strength and elongation. In powder metallurgy pressing, if the structure is three-dimensional, it cannot be completed. And for some heterosexual parts, the density of parts may be inconsistent due to inconsistent powder filling, so the parts that cannot be completed in powder metallurgy PM pressing are usually completed by MIM injection molding.

Expand reading of Metal Injection Molding Knowledge Points and Parts in Various Industries

The number of parts produced by MIM powder injection molding process is the lowest. Because the shrinkage rate is very large, the reason is that each blank formed by MIM injection molding contains a large amount of adhesives. These adhesives tightly wrap the injection powder to achieve the normal popularity of raw materials in the mold, so as to keep the density stable. However, these binders will fade in the process of degreasing and sintering, so the shrinkage rate of the product is relatively large, and the parts produced are produced in a one-time mass production if they want to keep constant. At this time, many people are worried about rust, but this is not true. If the stainless steel raw materials used in MIM injection molding are placed in a dry and normal environment, there will be no problem for two years. Secondly, the MIM mold can inject 2, 4, 8 and 16 pieces at a time. Therefore, small batch products are not suitable for MIM process. The sintering time of MIM injection molding is different from that of conventional powder metallurgy. The sintering time of conventional powder metallurgy parts is expected to be four hours, while the sintering time of MIM injection molding blank parts is expected to be twelve hours. The furnace temperature needs to be controlled, and the binder in the blank is slowly removed to achieve a more stable state of the blank.

In the production of high-density powder metallurgy parts, MIM injection molding has an advantage. The density can reach 7.6-7.8g, while the conventional powder metallurgy pressing is about 6.8. The density of production is different when raw materials with different productivity are selected. For example, if MIM is made of stainless steel, the density will be controlled to about 7.6. Superalloy shall be selected and the density shall be controlled at about 7.6. Kewa alloy is selected, and the density is controlled at 7.8. High specific gravity gold is used, and the density is controlled at 18.3. Because it contains tungsten composition, etc., there are several low density parts. Titanium alloy is selected, and the density of the injection molded parts produced is about 4.2. Usually, this will be used in aerospace technology, because the material density is low, and the body weight is reduced. It will also be seen in the mobile phone industry, because weight will affect the feeling of using a mobile phone. In the face of the rapid development of mobile phone industry, it may take only a few months for a project to come out of technology, so the MIM industry needs to understand the pulse of the industry and keep up with the pace of the times.

The following lists the MIM metal injection molding parts used in medical, automotive, electronic IT, aerospace, consumer goods, firearms and other industries

MIM produces orthodontic parts in the medical field. The product is very small. It was seen in the mouth of some orthodontic friends before menstruation. This part is made of 316L stainless steel.

Surgical instruments. Previously, surgery needed to be performed on the body. Now, surgery can be performed by making a hole in the body and using MIM metal injection molding surgical forceps. This technology is relatively new. The final shape of surgical forceps was completed by MIM technology around 2015. The stainless steel used has a density of about 7.65, an ultimate tensile strength of 900MPa, a yield strength of 730MPa, and a hardness of 25HRC.

The application of MIM in the automobile industry, such as thousands of temperatures in the engine, can be used in such an environment for injection molded parts made of Kova alloy materials. For example, the engine rocker arm, which is made of low alloy steel, controls the variable valve timing stroke of the engine. MIM is especially complex in structure and light in weight.

The blade on the turbocharger, which is used in the automobile diesel engine turbocharger, is completed by the successful MIM injection process. This part can meet strict dimensional tolerance requirements, and the blade profile can reach a precision of plus or minus 0.015mm by cutting. This blade is produced by a professional mold. This mold has an excellent slider function and can reduce deformation when it is released. MIM production can reduce the production cost by 20%.

MIM parts are used in electronic communication instruments in a large proportion, accounting for about 50% of all MIM industries. Plug sockets with complex shapes are basically MIM products and some electronic products. The low production cost, high performance requirements, and relatively small and complex parts are basically produced by MIM technology.

For example, the outer cover of optical fiber transceiver, which looks very complex, is also made of stainless steel MIM metal injection molding technology.

Mobile phone parts card inserter. One mobile phone can hold three mobile phone cards or two cards. The card holder is a MIM part. Now there are more aluminum and plastic parts used, which can reduce the weight of the mobile phone. Even if it is one gram, there are so many parts in the mobile phone, which together have obvious effects. To measure whether the universal device has market competitiveness, the feel of its use is very important.

The camera of the mobile phone, the filter screen of the mobile phone speaker, the slider and the hinge cylinder of the mobile phone are all completed by MIM injection molding technology.

MIM technology uses different materials, such as Kova alloy, which can effectively improve the high temperature resistance and reduce the weight of parts. This advantage is particularly suitable for the aerospace industry. For example, the seat belt parts produced with the advantage of high strength are also controlled at 100g. After heat treatment, the tensile strength of this complex part is 200MPA.

In the past, the compression seat of the oil outlet valve was completed by stamping and cutting, and its weight is not as strong as that of MIM manufacturing. Now it has been replaced by MIM powder injection molding. This saves a lot of production costs. Parts used in aerospace and medical are expensive. More importantly, unified production of MIM facilitates assembly and improves the performance of parts.

Rocket burner, which is a thruster device, is a niobium alloy part with geometric shape. It is a good choice to use MIM technology to complete too complex structure.

MIM is also often seen in daily necessities, such as parts in watches, parts in small motors, parts on eyes, photographic machinery, etc.

At the early stage of the development of MIM technology, as only a few competent enterprises owned and mastered these technologies, and later, they gradually became popular. MIM products have both small size, complex shape, high strength, medium or high surface roughness and medium or precise tolerance. Because the process is aimed at the final shape of the product, the injection molding blanks produced have basically been formed, saving expensive machining costs. When the number of required parts reaches a certain standard, the MIM process is competitive.

To fully understand the great benefits of MIM metal injection molding, we must know the advantages and disadvantages of MIM Wang Yi:

MIM process can make production highly automated, so it is most competitive for mass production

MIM parts can be designed into very thin walls, and can also have fine boring holes, threads and other details

Compared with cast metals and alloys, the price of raw materials for MIM process is higher. This is the main reason why MIM parts are usually quite small

Because the material cost of small parts only accounts for a small part of the total production cost

The MIM process is environmentally friendly. At the same time, it consumes less energy than other production processes. The more expensive the raw materials are, the greater the advantages will be.