The Primary Choice of “Green Auto” Manufacturing-Metal Injection Molding

Metal injection molding products(mim parts) used in automobiles are very high-tech products that can reduce the weight of automobiles and reduce the manufacturing costs. They also have the function of optimizing the production technology of automobile industry products and enhancing the competitiveness of the automobile industry. Currently, the metal injection molding parts are used in automobiles has more than 400 kinds.
As a typical net-final manufacturing technology, metal injection molding has advantages in many aspects such as energy saving, material saving, environmental protection, economy and high efficiency, and has been gradually recognized by various industries and widely used; especially, the application of automotive metal injection molding products With the rapid development of the metal injection molding industry has promoted the rapid development of the lane.

Metal injection molding parts can reduce costs and vehicle weight

metal injection molding parts used in automobile manufacturing are mainly sintered metal oil-bearing and metal injection molding structural parts, the former is mainly produced by 90Cu-10Sn bronze, the latter is basically made of iron powder as the basic raw material. Here are some examples of metal injection molding technology applications:
A metal injection molding 64-tooth power take-off drive gear saves about 40% less costly parts machined from steel and does not require subsequent machining of gears; a metal injection molding automotive manual transmission synchronizer ring, as compared to conventional production Of the synchronizer ring, can reduce the cost of 38%; a metal injection molding compound planetary gear carrier, the ultimate strength of castings than the cast iron 40% higher, while reducing the cost of more than 35% ...

Many award-winning mim parts show that metal injection molding parts cannot only replace die-casting parts, forgings, machined parts, it can save labor, save material, save energy, reduce production costs, but also reduce the weight of parts, which is conducive to lightweight vehicles. More importantly, the development of metal injection molding combination parts, marking that some parts can only be made using metal injection molding technology, has important technical and economic significance.

Metal Injection Molding is a “green manufacturing” technology

At present, metal injection molding has been recognized by the industry as a green, sustainable manufacturing technology.
In terms of continuous functionality, the ultimate metallization power and material utilization of metallurgical powder metallurgy minimize total energy consumption. Compared with the traditional process (hot working + cold working), casting or forging + cutting, metal injection molding process to manufacture the same part requires only a few steps, which can be completed more processes, more complex processes. The ultimate strength of metal injection molding is its main strength in terms of material sustainability.
For example, forming a toothed part can result in up to 40% of the material turned into chips in conventional cutting processes, whereas 85% of the total powder metallurgy is produced from recycled material. In the production of metal injection molding parts, waste loss of each process is generally 3% or less, the material utilization rate of up to 95%.

In terms of energy sustainability, the conventional traditional manufacturing process requires several heating and reheating processes to finalize the shape. When atomizing the steel powder or iron powder, only the scrap material needs to be melted once, and all other heat Processing operations are carried out below the melting temperature of the temperature, so that not only energy saving but also can be made into the final shape and the formation of the required material properties, mechanical properties. A comparison of material utilization rates for metal forming found that the energy required to make metal injection molding parts was 44% of forged-machined parts.
In terms of environmental sustainability, due to the ultimate shaping ability of metal injection molding, finished parts are usually produced after sintering, ready for packaging and delivery. In most cases, the cutting oil used to process metal injection molding products is negligible, and the amount of toxic pollutants released by sources such as cooling water is small. Compared with other manufacturing processes, the metal injection molding parts industry is almost harmless to the environment.
Metal injection molding parts is already an indispensable basic type of automobile industry, many world-renowned metal injection molding enterprises have also established wholly-owned enterprises in China, personally believe that in the near future, China will gradually become one of the largest distribution centers of auto mim parts.

Structure Of Metal Powder Injection Mold

Mold is the foundation of the industry. Mold technology, to a large extent, determines the cost of the product, good quality, and even functional features. Metal powder injection molding mold is the basic component of the MIM process.The main structure of metal injection molding mold (commonly known as MIM mold) and the structure of the traditional plastic mold are roughly the same, the casting system, forming parts and structural parts of the three major components. Among them, the pouring system and the forming part are the parts that are in direct contact with the filling mold and are the parts with the highest processing finish and precision in the mold.

The Casting System
Refers to the molten material from the nozzle into the cavity before the runner part, including the main runner, cold material points, runners and gates and so on. The main channel refers to the nozzle to the diversion flow or cavity of a passageway, generally conical, the top is concave, in order to connect with the nozzle; cold material hole is located at the end of the main channel for a hole to cover the nozzle The two ends of the cold material between the injection to prevent the blockage of the runner and gate; shunt is the main runner and the gate between the gate, the general multi-cavity mold; gate is the shunt and type Cavity connection point, the molten material through the gate into the cavity forming.

The Forming Parts
Refers to the shape of the various components, including dynamic mode, fixed mold and cavity, core, forming rod and exhaust and so on. The movable mold is installed on the moving template of the injection machine, and the fixed mold is installed on the fixed mold of the injection machine. When working, the movable mold and the fixed mold are closed, and the core and the parting cavity form the cavity of the mold. Exhaust port is a slot-shaped air outlet provided in the mold for discharging the gas introduced by the melt.

The Structural Components
Including the guide, stripping, core-pulling, sub-type, such as before and after deduction template, bearing plate, guide column, stripping plate, stripping rod and so on. Guide components are to ensure that the movable mold and fixed mold can be accurately aligned in the mold clamping, the guide member must be set in the mold for positioning; demolding parts for the introduction of shaped parts and reset; some of the more complex shapes of the product Need to design the core, the core can be removed after the smooth release.

With more and more widely used products, the requirements are getting higher and higher, MIM mold manufacturing and design processes must also continue to improve in order to meet the needs of product development.

What Materials Would Be The Future Trend Of Metal Injection Molding?

With the development of MIM technology, we’ve used different kinds of material on this technology such as Iron Based, Low Alloy Steel, and Stainless Steel became the most popular material for applying. In the nearly future, we’re gonna believe more and more materials would be used in this advanced metal parts manufacturing process. So we list some materials that seem most likely to be used in Metal Injection Molding(MIM).

1. Nickel-free stainless steel
In the currently widely used medical austenitic stainless steel 316L and 17-4PH, nickel is an important alloying element. The main role of nickel is to form a stable austenitic stainless steel structure, thereby improving the corrosion resistance of stainless steel, plasticity, weldability and toughness properties, under room temperature stable austenitic stainless steel can also be made with non-magnetic .

However, nickel is a potential allergic factor, and a large number of clinical manifestations in the West confirm that nickel and its compounds can be harmful to humans. The most common damage is contact dermatitis, eczema occurs in patients with strong allergies.

At present, the EU has issued a ban on nickel, which be fully implemented by the end of 2016. The alternative is to use high-nitrogen, nickel-free chromium-manganese-molybdenum steel, which is exactly the strength of MIM technology.


2. Copper and brass
Metallic applications are magnetically non-conductive and are good materials for 3C products. Due to the MIM technology is economy and affordability, copper alloys should be a good option, but in the past few people concered sintering of copper alloys, mainly because the copper alloy plumbing equipment can be achieved through die-casting, the sintering of pure copper can not be done with normaly sinter furnace, the pressure must be greater than one atmosphere above the high-pressure sintering furnace, not the general factory can be set, mainly copper (and its alloys), low vapor pressure, vaporization has not yet reached the sintering temperature is quite serious, in addition to easy get contaminated of the furnace wall, the product is not easy to burn dense.

PIM International magazine 2015 first issue reported that the world's largest MIM / PM powder consumption in mainland China and Taiwan, but apparently only emphasis on heat pipes and heat sinks, and a small part of the bronze self-lubricating bearings and filters. For copper and Copper alloy MIM products, still to be developed. Normally, this material is expected to have the opportunity to quickly gain in value through the adoption of Apple computers.


3. Titanium and titanium alloys
Titanium and titanium alloys have always been the star material, but the price is too high, the source of powder is limited, so industrial applications are confined to the aviation buckle, special parts, and medical devices and implants, a small part of the wearable products , But due to the appearance of titanium is easy to lead to decoration is not good enough looking, a lot of stainless steel polishing to PVD is black, that only a thin layer of titanium surface, not enough to be called titanium. We also look forward to market development and nickel-free stainless steel era, high strength and relatively low proportion of titanium has its excellent mechanical and human affinity, to look forward to the extensive use of MIM titanium parts.


4. Functional metals and ceramics
Since 2017 the most discussed, most mysterious and the popular, I believe that is a functional material, due to many special applications, related materials such as various non-ferrous metal alloys, functional ceramics and so on. For example, soft magnetic materials such as cobalt-chromium-molybdenum alloy (CoCrMo) or cobalt-iron (Hiper Co), ceramics are even more varied.