Fascination about mim supply online

Metal injection molding (MIM) is a manufacturing process that combines the benefits of plastic injection molding and powdered metallurgy to produce complex metal parts. There are several online suppliers that specialize in MIM and offer a wide range of services and products. Some of the reasons why people are fascinated by online MIM suppliers include:

Accessibility: Online MIM suppliers provide easy access to a variety of metal injection molding services and products. Customers can browse through their catalogs, compare options, and place orders from anywhere in the world, making it convenient for both individuals and businesses.

Customization: Online MIM suppliers often offer customized solutions to meet specific design requirements. Customers can provide their design specifications, and the supplier can produce parts that meet their unique needs. This level of customization is particularly appealing for industries that require intricate and complex metal components.

Expertise and knowledge: Online MIM suppliers typically have a team of experts who are experienced in the field of metal injection molding. They can provide guidance and recommendations on material selection, design optimization, and production processes. This expertise is valuable for customers who may not have extensive knowledge about MIM.

Cost-effectiveness: Online MIM suppliers often offer competitive pricing due to their streamlined operations and reduced overhead costs. Customers can compare prices from different suppliers and find the most cost-effective options for their projects. This affordability is attractive for both small-scale projects and large-scale production runs.

Quality assurance: Reputable online MIM suppliers prioritize quality assurance and adhere to strict manufacturing standards. They often have quality control processes in place to ensure that the final products meet the required specifications. This commitment to quality gives customers confidence in the reliability and performance of the MIM parts they purchase learn more.

Quick turnaround time: Online MIM suppliers understand the importance of fast turnaround times for their customers. They strive to minimize production lead times and offer expedited shipping options to ensure timely delivery. This efficiency is crucial for industries that have tight production schedules or urgent project requirements .

In summary, the fascination with online MIM suppliers stems from their accessibility, customization options, expertise, cost-effectiveness, quality assurance, and quick turnaround times. These factors make online MIM suppliers an attractive choice for individuals and businesses seeking metal injection molding solutions.

Basic Concept

MIM (Metal Injection Molding) is a molding method that injects metal powder and its binder plasticizer mixture into the model. It is a new type of parts and components that introduces modern plastic injection molding technology into the field of powder metallurgy, and combines plastic molding technology, polymer chemistry, powder metallurgy technology and metal materials science and other disciplines. “Near-net molding” technology.

MIM and CIM (Ceramic Injection Molding ceramic powder injection molding technology) belong to the same powder injection molding (PIM), MIM and metal additive manufacturing (MAM), isostatic pressing (IP) belongs to the powder metallurgy (Powder Metallurgy, PM) of the different types of processes.

MIM not only has the advantages of conventional powder metallurgy process with fewer procedures, no cutting or less cutting, and higher economic benefits, at the same time, it overcomes the main shortcomings of the traditional powder metallurgy process products with uneven material, low mechanical properties, thin-walled not easy to form and complex structure, and is suitable for the mass production of small, precise, three-dimensional shape of the complexity of the metal parts and components with special requirements of the manufacturing. From an economic point of view, MIM products usually weigh about 0.1-200g, less than 50 grams is the most economical, can produce plastic products like molding a variety of complex shapes; product surface finish is good, high dimensional accuracy. Wall thicknesses of less than 6 mm are optimal for MIM. Thicker outer walls are also possible, but the cost increases due to longer processing times and the addition of extra material. Alternatively, very thin walls of less than 0.5 mm are also possible for MIM, but with high design requirements .

MIM can be used with almost most metal materials, and the main applications cover iron-based, nickel-based, low-alloyed, copper-based, high-speed steel, stainless steel, carbide, and titanium-based metals, given the economics.

McKinsey’s Advanced Manufacturing & Assembly Survey Report, published in May 2020, shows that MIM technology is ranked second among the top 10 advanced manufacturing technologies globally.

The market size to $5.87 billion in 2020 and is expected to reach $8.26 billion in 2026, corresponding to a compound annual growth rate (CAGR) of 7.87% from 2019-2026. China’s MIM market accounts for about 40% of the global market, and the MIM market size is expected to reach $24.14 billion in 2026.

Process Flow

MIM basic process flow chart

During the manufacturing process of MIM products, the raw materials and the process itself are characterized by large shrinkage rate (about 15-18%). At the same time, MIM process is often used in complex structure products, in the process of injection molding, degreasing, sintering process, under the dual influence of different product design features and the gravity field effect of the way of placing, there are certain differences in the shrinkage rate of the product in different directions and structures, which makes it difficult to control the size.

Mixing and feeding

Fine metal powder is mixed with thermoplastic and paraffin binder according to the precise proportion, and heated to a certain temperature to make the binder melt and evenly coated on the metal powder particles to form raw materials. The degree of homogeneity of the mixture directly affects its flowability and thus the parameters of the injection molding process as well as the density and other properties of the final material.

The mass ratio is about 90% metal powder mixed with 10% binder to form a homogeneous feedstock. the size of the metal powder particles used in the MIM process is generally in the range of 0.5~20m.

The role of the organic binder is to bond the metal powder particles, so that the mixture is heated in the barrel of the injection molding machine with rheological and lubricating properties, i.e., the binder is the carrier to drive the powder flow. Therefore, the choice of binder is the key to the whole powder injection molding. Requirements for organic binder: small amount, with less binder can make the mixture to produce better rheology; non-reactive, in the process of removing the binder and the metal powder does not have any chemical reaction; easy to remove, no carbon residue in the product.

Injection molding

The special feeding material is loaded into the barrel of the injection machine and then heated to the specified temperature (generally the binder melting temperature, between 170-195 ℃) so that it has the fluidity, injected into the customized molds under the appropriate pressure, forming the birth blanks. The dimensions of the mold cavity are designed to take into account the shrinkage that occurs during the sintering of the metal part.

The core of the process is that due to the wide variety of metal powders and the different content of various feed ingredients, the setting of parameters and other aspects of the injection molding process is very important, and operational errors can cause product defects. The company’s technicians continuously optimize the injection molding process through the simulation of the injection molding process, the design and manufacture of molds and the adjustment of parameters to improve the injection capacity and ensure the uniformity of injection.

Degreasing

The physical or chemical removal of the binder in the blank changes the part from a mixture of metal powder and binder to a simple degreased blank (brown blank, with tiny pores), with no change in shape or structure. The degreasing process must ensure that the binder is gradually discharged from the different parts of the blank along the tiny channels between the particles without reducing the strength of the blank, while maintaining the form of the product.

The core of the process is: to control the residual amount of binder in the blank, if the degreasing process is not in place, the binder residue is too much, high temperature sintering a large number of binder decomposition and gasification easily caused by the product cracking; if the degreasing is too much, it may cause metal oxidation of the product, the structure of the deformation of the undesirable consequences. Therefore, the selection of degreasing process and the control of process parameters are particularly important.

Sintering

Sintering is carried out in a sintering furnace with a controlled atmosphere. The degreased blanks are placed into a high-temperature, negative-pressure-controlled apparatus and slowly heated under the protection of a gas to remove residual binder. After the binder is completely removed, the blanks are heated to high temperatures and the voids between the particles disappear due to the fusion of the particles, which ultimately directionally shrinks to its design size and transforms it into a dense solid to form a sintered part (silver billet) that remains unchanged in shape and structure. For most materials, typical sintering densities are theoretically greater than 97%. High sintered densities allow products to perform similarly to forged materials.

The high densification of MIM parts is achieved by high sintering temperatures and long sintering times, which greatly increase and improve the mechanical properties of the part material. The core of the process: due to the existence of pores between the particles, the blank will shrink during sintering. Different materials have different shrinkage rates in the sintering process, generally in the range of 15%-18%, and controlling the shrinkage rate by controlling the sintering time, temperature and other parameters is the core. The sintering process has a great or even decisive influence on the metallographic organization and properties of the final product.

Post-processing

The precision of sintered parts under MIM process is generally 0.3%. In order to eliminate the shrinkage difference of the products during the sintering process and homogenize the product quality, and at the same time, in order to meet the customer’s requirements for higher precision size specifications of the products, different applications or different surface treatments, necessary post-treatments are required, including shaping, CNC, tapping, sandblasting, laser engraving, polishing, grinding, cleaning, PVD and other processes.

Technical Advantages

(1) Highly complex structural parts can be molded

Injection molding process technology using injection molding machine injection molding product blanks, to ensure that the material is fully filled with mold cavities, which also ensures the realization of highly complex structure of the parts. Previously, in the traditional processing technology first made into individual components and then combined into components in the use of MIM technology can be considered integrated into a complete single part, greatly reducing the number of steps to simplify the processing procedures.MIM and other metal processing methods, products with high dimensional accuracy, do not have to carry out secondary processing or only a small amount of finish machining. Injection molding process can be directly molded thin-walled, complex structural parts, product shape has been close to the final product requirements, parts size tolerance is generally maintained at 0.1 ~ 0.3 or so, especially for reducing the difficult to machine the processing cost of cemented carbide, reduce the loss of precious metal processing is particularly important. There is no restriction on shape design, which is applicable to almost all products, and the tolerance that cannot be achieved by MIM primary molding can be realized with the help of surface treatment.

(2) Uniform microstructure, high density and good performance of products

In the pressing process, due to the friction between the mold wall and the powder and the powder and the powder, the pressing pressure is not uniformly distributed, which also leads to the uneven microstructure of the pressed blanks, which will cause uneven shrinkage of the pressed powder metallurgy parts in the sintering process, and therefore have to lower the sintering temperature in order to reduce the effect of this effect, which results in large porosity of the products, poor densification of the material, low density, which seriously affects the mechanical properties of the products. The mechanical properties of the products. On the contrary, the injection molding process is a fluid molding process, the presence of the adhesive guarantees the uniformity of the powder arrangement, thus eliminating the unevenness of the microstructure of the blank, which in turn allows the density of the sintered products can reach the theoretical density of its material. In general, the density of pressed products can only reach a maximum of 85% of the theoretical density. The high density of the product can make the strength increase, toughness, ductility, electrical and thermal conductivity has been improved, magnetic properties.

(3) high efficiency, easy to achieve large quantities and large-scale production

MIM technology using metal molds, its life and engineering plastics injection molding with mold equivalent. Due to the use of metal molds, MIM is suitable for mass production of parts. Due to the use of injection molding machine forming product blanks, greatly improving production efficiency, reduce production costs, and injection molding product consistency, repeatability, thus providing a guarantee for large quantities and large-scale industrial production.MIM is a flexible process, the annual demand for a few thousand to a few million of the production can be very economical to achieve. And casting parts, injection molded parts, MIM requires customers to invest in molds and tooling costs, so for small quantities of products, usually affects the cost estimate.

(4) Wide range of applicable materials and application areas

The materials that can be used for injection molding are very wide, in principle, any powder material that can be poured at high temperature can be manufactured into parts by the MIM process, including difficult-to-machine materials and high melting point materials in the traditional manufacturing process. In addition, MIM can also be based on user requirements for material formulation studies, manufacturing any combination of alloy materials, composite materials molded into parts.MIM can deal with a lot of materials, low alloy steel, stainless steel, tool steel, nickel-based alloys, tungsten alloys, cemented carbide, titanium alloys, magnetic materials, Kovar alloys, fine ceramics and so on. While the non-ferrous alloys aluminum and copper are technically feasible, they are usually handled by other more economical means, such as die casting or machining.

(5) MIM process using micron-sized fine powder, particle size diameter of 2-15m, while the traditional powder metallurgy raw material powder particle size of 50-100 m. Small particle size can accelerate the sintering contraction, help improve the mechanical properties of the material to extend the fatigue life of the material, but also improve the resistance to, stress corrosion and magnetic properties. Fine particle size, not only the cost increases (about 1-10 times the price of traditional PM powder), but also easy to agglomerate, increasing the difficulty of mixing uniformity, and the rate of degreasing is relatively slow, thus reducing the productivity of the MIM process. Compared with the traditional powder metallurgy process, the MIM process adds about 30~55% (v/v) of organic binder in order to ensure smooth mold filling of the powder binder system in the injection, so in order to get a high density end product, it is necessary to use a micro-fine powder with high sintering drive. The selection of fine powders has the added benefit of a good surface finish on the sintered product. In order to ensure the sinterability and material properties of MIM parts, the higher the purity of the powder used, the better, and the lower the oxygen content, the better.

Optimal requirements of MIM for virgin powders

For complex parts, traditional metal forming usually breaks down and creates individual parts before assembling them. The MIM process is much more economical by machining the whole part and simplifying the machining process. Moreover, the cost of traditional metal forming rises as the complexity of the part increases, while the MIM process keeps the cost constant by increasing the complexity of the mold, and the higher the complexity of the product, the more economical the MIM process is, and the cost advantage is more obvious.

MIM process has a higher density of finished products, the relative density of 95% to 98%, while the relative density of traditional powder metallurgy process is only 80% to 85% (mainly due to the use of micro-fine powder in MIM process); MIM product shape can be three-dimensional complex shapes, while traditional powder metallurgy product shape is usually two-dimensional simple shapes. MIM process has the advantages of traditional powder metallurgy process, but its shape has a high degree of freedom that traditional powder metallurgy process can not achieve. The traditional powder metallurgy process is affected by the strength of the mold and the filling density, the molding shape is mostly two-dimensional cylindrical.

The traditional precision casting de-drying process is an effective technology for making complex shaped products. In recent years, the use of ceramic core assistance can complete the manufacture of slits and deep holes, but by the strength of the ceramic core as well as the limitations of the fluidity of the casting liquid, there are still some technical difficulties in this process. Generally speaking, the process of manufacturing large and medium-sized parts is more suitable, manufacturing complex shape of small parts is more suitable to MIM process. Die casting process for aluminum and zinc alloys and other low melting point, cast liquid fluidity of good materials, the process of products due to material restrictions, its strength, wear resistance, corrosion resistance have certain limits. MIM process can be processed raw materials are more. Precision casting process in recent years, although the accuracy and complexity of its products have improved, but still not as good as the dewaxing process and MIM process. Powder forging is an important development, has been applied to the mass production of connecting rod manufacturing. However, in general, the cost of heat treatment and die life in forging engineering are still problematic and need to be further addressed.

Traditional machining processes rely on automation to enhance their machining capabilities, and there has been great progress in terms of effectiveness and accuracy, but the basic program is still inseparable from step-by-step machining (turning, planing, milling, grinding, drilling, polishing, etc.) to complete the shape of the part. The machining accuracy of the machining method is much better than other machining methods, but because of the low effective utilization of materials, and the completion of its shape is limited by equipment and tools, some parts can not be completed by machining. On the contrary, MIM can effectively utilize the material without restriction, for the manufacture of small, difficult shape of the precision parts, MIM process compared to machining, its lower cost and high efficiency, has a strong competitive edge.

MIM technology does not compete with traditional machining methods, but rather makes up for the technical deficiencies of traditional machining methods or the defects that cannot be produced.MIM technology can play its specialty in the field of parts made by traditional machining methods.

Industry Chain

The upstream industry mainly provides product raw materials, including metal powder, binder, etc., belonging to the metal and chemical industry, respectively, the industry is relatively mature, the market supply is sufficient to fully meet the development needs of MIM products.The application of MIM downstream industry in our country is mainly distributed in the consumer electronics industry, and is gradually applied to automobile manufacturing and medical equipment and other industries.

In 2020, the total sales of MIM powder in China will be about 12,000 tons, and the market share of domestic brands will be about 79%; the international brand products will still be dominated by the feeding material (injection material) of German BASF, accounting for about 84%.

At present, MIM material varieties are still dominated by stainless steel due to the market demand of consumer electronics. With the downstream areas of material diversification and product lightweight and other differentiated needs continue to improve, consumer electronics parts materials are also non-magnetic and harmless (such as high-nitrogen nickel-free stainless steel, copper alloys, aluminum alloys) and a combination of materials (such as metal – ceramics, metal – plastics) the direction of development. Titanium and titanium alloys are also expected to become the next generation of star materials after stainless steel, and are widely used in high-end fields such as automotive, medical, and hardware go coupon.

Downstream Application

MIM has a wide range of applications, and the MIM products that penetrate into our lives mainly lie in the three major fields of electronic products, automobile manufacturing and medical devices.

Consumer Electronics

Traditional consumer electronics products usually include smart phones, tablet PCs, laptops, digital cameras and other hardware devices, and emerging consumer electronics devices include smart wearable devices, drones and so on.

In 2010, BlackBerry’s signage appearance parts adopted MIM process technology, which opened up the batch use of MIM parts in cell phones; Apple began to use MIM parts since 2010, and has continued to expand and lead the use of MIM, the successful application of MIM parts in cell phones, such as power supply interface parts, card bracket, camera ring, keys, etc., which has accomplished the success of China’s MIM enterprises The successful application of MIM parts such as power connector, card holder, camera ring, keypad, etc. in mobile phones has made Chinese MIM enterprises a leading position in consumer electronics. With the development of smart phones, smart wearable devices and other consumer electronics products to thinner and lighter, the core components of these products will be more sophisticated and complex. Against this backdrop, the application of MIM technology will become increasingly promising.

Electronic communication products is an important market for MIM parts, almost all cell phone manufacturers will purchase a large number of MIM products, and communication in the miniature and multi-functional parts are suitable for MIM technology advantages.

Phone card holder – a very classic MIM product.

Hinges for folding screen cell phones

The hinge for folding screen requires very high precision and is very difficult to produce, probably only MIM can do it.

MIM injection molded communication parts

Automotive

MIM began to be used in the automotive parts market in the 1990s. At present, the automotive industry has adopted the MIM process to produce a number of complex shapes, bimetallic parts, as well as groups of micro-small parts, such as turbocharging parts, regulating rings, injector parts, blades, gearboxes, power steering components and so on. The automotive field industry is the largest user of MIM injection molded parts, accounting for about 60% of the MIM industry.

North America, Japan, Europe, powder metallurgy parts for a single vehicle usage of 18.6kg, 8kg, 7.2kg, China is only 4.5kg, which also predicts that in the next stage, China’s domestic automotive MIM parts products market potential is huge. Taking into account the MIM process to meet the auto parts “miniaturization, integration, lightweight” development trend, it is expected that the future penetration of the MIM process in the field of automotive parts will increase.

MIM injection molding automotive parts

Medical field

In the field of medical devices, the medical parts produced by the MIM process have high precision, and can meet the requirements of most precision medical devices for parts that require small size, high complexity, high mechanical properties and so on. In recent years, the MIM process has been more and more widely used, such as scalpel handles, scissors, tweezers, dental parts, orthopedic joint parts and so on. In the medical field of the use of MIM material requirements are relatively high, the unit price of a single MIM injection molding parts is much more expensive than the use of MIM parts in industry.

Medical equipment is the important foundation of China’s health care system, in recent years, the medical equipment market shows a growing trend, the application of MIM products in this field will also continue to grow.

Power tools

The machining of power tool parts is more complicated, with higher processing cost and lower material utilization rate, which is more dependent on MIM. Products developed in recent years such as shaped milling cutters, cutting tools, fasteners, micro gears, cotton loosers / textile machines / crimping machine parts. The power tools industry is mainly driven by manufacturing, construction, automotive, and consumer durables industries.

Development Trend

At the present stage, China’s MIM products are mostly made of stainless steel and iron-based alloy powder, which are widely used in consumer electronics, etc. The research and development of new materials in the MIM industry focuses on duplex stainless steel with high strength and corrosion resistance, copper alloys with high strength and thermal conductivity, and titanium alloys with high strength and biocompatibility, and its applications are developing in the direction of high-end fields such as automotive, medical, and hardware. MIM-Titanium Alloy

MIM-Titanium Alloy Application

At present, the research of MIM titanium and titanium alloys has made some progress, but there are still some difficulties in large-scale industrialization and application, mainly the following points:

Low-oxygen spherical titanium and titanium alloy powder is expensive; although domestic spherical titanium and titanium alloy powder manufacturers have developed rapidly in recent years, there is still a gap between them and the global leading technology;

Selection of binder and degreasing removal process; the selection of binder determines the size of the powder filling volume, which has a direct impact on the density, shrinkage and surface roughness of the sintered product, while the efficient degreasing removal process helps to reduce the impact of impurity elements, such as C and O, and improve the performance of the product;

Sintering process optimization and equipment requirements; due to the characteristics of high activity of titanium alloys, the control of temperature and oxygen content during sintering is crucial, which puts higher requirements on the sintering furnace.

Micro-powder injection molding, ultra-large injection molding and co-injection molding technology processes will become an important development direction for the industry. Micro-powder injection molding will promote the development of MIM products in the direction of smaller and finer; oversized injection molding by reducing the amount of binder to increase the size of the product, to promote the application and popularization of oversized MIM products; co-injection molding can be magnetic and non-magnetic materials, hard and soft materials, conductive materials and insulating materials organic combination, thereby effectively improving the applicability of MIM products.

Feeding refers to the uniform mixing of certain metal powder and binder at a certain temperature and in a certain proportion, in order to obtain a mixture of powder and binder suitable for injection molding. The preparation of homogeneous feed is the key to obtaining high-precision powder injection molding products. If the feed is not homogeneously mixed, the binder will produce defects such as deformation in the degreasing process and uneven sintering shrinkage, which will increase the dimensional deviation of the final sintered body. Therefore, the preparation of feed material plays a decisive role in the accuracy of MIM products. At this stage, the industry’s feed to external procurement-based enterprises, customized feed preparation often become the shortcomings of its technological development, the future of the enterprise’s feed autonomy will become the trend.

The industry’s demand for automated intelligent production equipment and testing equipment is growing, and the degree of automation and intelligence is rapidly increasing.

In China’s MIM industry, some enterprises already have strong technological innovation strength, such as ultra-thin, high-precision MIM product development, in line with the development trend of thin and lightweight consumer electronics products, portable; and then, for example, through the research and development of feeding and molds, to further enhance the MIM products of high complexity, high precision, high strength, exquisite appearance and other characteristics, to promote the use of MIM products in automotive manufacturing and medical equipment and other diversified fields. This will lead to the popularization and application of MIM products in automobile manufacturing and medical devices and other diversified fields.