Process and application of metal powder injection molding
time：2020-04-23Views：391 Author：Best Seiko
Metal powder injection molding is a metal processing process in which a measured amount of fine powder metal is mixed with a binder material to include "raw materials" that can be processed by a method called injection molding through plastic processing equipment. The molding process allows complex parts to be molded in a single operation in high volumes. End products are usually component projects used in various industry applications. The nature of the flow rate of MIM feedstock is defined by a physics called rheology. Current equipment functions require processing to be limited to products that can be molded using 100 grams or as few as "shots" down to a typical roll of mold. Rheology does allow this “shooting” to be assigned to multiple holes, thereby becoming cost-effective, otherwise it will be quite expensive to produce small, complex, high-volume products produced by spare or classic small methods. The implementation of various MIM raw materials within the metal is called powder metallurgy, and these contain the same alloy composition found in industry standards for common and foreign metal applications. The subsequent adjustment operation is carried out in a molded shape in which the binder material is removed and the metal particles are merged into the state required for the metal alloy. Best's metal powder injection molding process Metal powder injection molding process: MIM received attention throughout the 1990s as an improvement to the subsequent conditioning process led to the end product, which performed similar or better than through a competitive process to get better. The improved cost efficiency of the MIM technology through mass production, the "near net type", negates the expensive, extra operations left unrealized in the competitive process, and met with strict dimensional and metallurgical specifications. Metal powder injection molding electronic parts production method steps include combining metal powder with a binder of wax and plastic to produce a combination of "raw materials" that are injected into a hollow mold using an injection molding machine in a liquid state. The "green parts" are cooled and de-molded in a plastic molding machine. Next, a portion of the binder material is removed with a solvent, hot furnace, catalytic method, or combination of methods. The resulting, fragile, porous (2-4% "air") part, in a pre-work condition called "brown", needs to condense the metal in a process called sintering furnace. The sintering temperature of the MIM part is almost high enough to melt the entire metal part directly (up to 1450 degrees Celsius), bonding together on the surface of the metal particles, resulting in a final solid density of 96-99%. The MIM metal of the final product has comparable mechanical and physical properties and the parts are made using traditional metal processing methods, and the MIM material is treated with the same subsequent metal conditioning, such as electroplating, passivation, annealing, carburizing, nitriding, Compatible with precipitation hardening. Application of metal powder injection molding: The window of metal injection parts lies in the complexity and volume of small-sized parts. MIM materials are comparable to metals formed by competitive methods, and end products are used in a wide range of industrial, commercial, medical, dental, gun, aviation, and automotive applications. A dimensional tolerance of ±0.003 inch per linear inch can be held together, and expertise in forming and sintering is possible when tolerance is closer to the limit. MIM can produce items that are difficult or even impossible to manufacture efficiently through manufacturing and other means. The increase in cost is a mark, and MIM operations that do not usually increase the cost are inherently complex due to the flexibility of injection molding. Traditional manufacturing methods, such as internal/external threads, miniaturization, or brand identity. Design functions that can be implemented into MIM operations include batch codes, part numbers, or date stamps of molded ingredients; parts manufacturing, whose net content reduces material waste and cost; density control at 95-98%; parts and complex 3D The fusion of geometric patterns. The ability to merge several businesses into one process, to ensure that MIM successfully saves delivery time and costs, and vendors provide significant benefits. The metal injection molding process is also considered to be a green technology due to a significant reduction in waste compared to “traditional” manufacturing methods such as 5-axis CNC machining. There is a wide range of materials available when using the MIM process. Traditional metal machining processes often involve a significant amount of material waste, which makes MIM an efficient choice for complex components, including expensive/special alloys (cobalt-chromium alloys, 17-4 PH stainless steel, titanium alloys, and tungsten carbides) manufacture. MIM is in thin-walled specifications (ie, 0.008 thick) and requires a viable option. In addition, the requirements of EMI shielding (electromagnetic interference) have presented unique challenges, and the utilization rate of special alloys (ASTM A753 Type 4) is currently being successfully achieved.