In today's highly developed manufacturing industry, the demand for complex shapes, high precision and high performance metal parts is increasing day by day. Metal Injection Molding (MIM), as an advanced near-net forming technology, is gradually emerging as a key player in many industries, opening up new avenues for modern precision manufacturing.

The metal injection molding process combines the design flexibility of plastic injection molding with the material property advantages of powder metallurgy. The basic principle is to mix the metal powder with an appropriate amount of binder to form a feedstock with good fluidity. The feedstock is then injected into the cavity of a precision mold, as in plastic injection molding, and cooled and cured to produce a blank with a certain shape and strength. Next, the binder in the billet is removed by degreasing process, and finally, sintering process is carried out to make metallurgical bonding between the metal powder particles, so as to obtain a dense finished metal part.

Metal injection molding exhibits great flexibility in terms of material selection. Almost all metals and alloys that can be made into powder can be applied to the process, commonly stainless steel, iron-based alloys, nickel-based alloys, titanium alloys, cemented carbide and so on. For example, stainless steel parts molded through the MIM process have good corrosion resistance and mechanical properties, and are widely used in medical devices, watch accessories, cell phone cartridges and other products. Titanium alloy is favored in high-end fields such as aerospace and medical device implants due to its high strength, low density and excellent biocompatibility.

The metal injection molding process offers a number of significant advantages. First and foremost is its exceptional design freedom, which enables the manufacture of complex shapes that are difficult to achieve with traditional machining processes. Whether it's a part with a complex internal cavity structure or a component with fine thin-walled features, MIM can handle it with ease. This design flexibility provides a wide space for product innovation, allowing designers to break through the limitations of traditional processes and design more optimized and functional product structures.

High precision is another major feature of metal injection molding. In the injection molding process, the high precision of the mold to ensure the dimensional accuracy of the blank, after the subsequent degreasing and sintering process, the dimensional accuracy of the final product can usually be controlled within ±0.3%, the surface roughness can be up to Ra0.8 - 3.2 μm, which makes the MIM process parts in many cases do not need to carry out a large number of subsequent processing, can be directly applied to the assembly, a significant savings in production costs and processing time. production costs and processing time.

Metal Injection Molding has a wide range of applications in various industries. In the electronics industry, many of the tiny but complex shaped metal structural parts in smart phones, such as camera mounts, SIM card holders, buttons, etc., are manufactured by MIM process. These parts not only require high precision and good mechanical properties, but also need to meet the needs of mass production, which MIM process can fit perfectly. In the field of medical devices, stainless steel and titanium alloy medical device parts produced by MIM process, such as dental implants, orthopedic implants, surgical instruments, etc., their high precision and biocompatibility provide a strong guarantee for the performance and safety of medical devices. In the automotive industry, some special shaped parts in the engine, automotive locks, sensor housings, etc. are also gradually adopted MIM process production, which helps to improve the performance and reliability of automotive parts, while reducing production costs. In the aerospace field, for some high-performance, lightweight and complex shape metal parts, such as turbine blades, aircraft engine nozzles, etc., metal injection molding process is also constantly exploring and applying, for the development of aerospace technology to contribute.

Although metal injection molding process has many advantages, but it is not perfect. For example, the initial mold development cost is high, need to invest a lot of money and time for mold design and manufacturing; the choice of binder system and the control of degreasing process is more complex, need precise process parameters and professional technicians to operate; and, the process of the raw material requirements are high, the particle size of the metal powder, purity, and so on will affect the quality of the final product. However, with the continuous development and progress of technology, these problems are gradually being solved. The research and development of new binder makes the degreasing process more efficient and environmentally friendly; advanced mold manufacturing technology reduces the mold development costs; the improvement of raw material preparation technology also provides better quality metal powder for MIM process.

Looking to the future, metal injection molding process has broad prospects for development. With the continuous innovation of science and technology, material science, mold manufacturing technology, automated production technology will further promote the development of MIM process. New metal materials and alloy systems will continue to be developed and applied to expand the range of materials for MIM process; the digitalization and intelligence of mold manufacturing will improve the precision and production efficiency of the mold; the popularity of automated production lines will realize the large-scale and high-efficiency production of MIM process. At the same time, with the increasingly stringent environmental requirements, green MIM process will also become an important direction of development, such as research and development of biodegradable binder, optimization of degreasing and sintering process to reduce energy consumption and pollutant emissions.

As an advanced precision manufacturing process, metal injection molding occupies an important position in modern manufacturing industry. It provides strong technical support for product innovation and development in a wide range of industries with its unique process principles, superior performance advantages and wide range of applications. Although there are still some challenges, with the continuous progress and improvement of technology, the metal injection molding process will certainly play a more important role in the future manufacturing industry, creating more high-performance, high-precision, complex-shaped metal parts, and promoting the entire manufacturing industry to a higher level.