MIM Process Flow and Advantages of Metal Injection Molding

Oct 14, 2022

1、summary Metal injection molding (MIM) is a typical interdisciplinary product, integrating two completely different processing technologies (plastic injection molding and powder metallurgy). It enables designers to get rid of traditional constraints and obtain low-cost, special-shaped stainless steel, nickel, iron, copper, titanium and other metal parts by plastic molding, thus having greater design freedom than many other production processes.
2、Pre sales evaluation The presales team of Zhongwei Precision will work closely with you to determine whether the products to be processed are suitable for MIM process manufacturing in terms of cost, materials and manufacturing feasibility. At the same time, engineers will also give suggestions to change the design so as to achieve optimization effect through MIM
3、Raw materials The special metal powder (micron level) is mixed with high quality polymer to form a special feed for MIM through the precisely controlled preparation process. Compared with traditional powder metallurgy, the particle size of metal powder (micron level) and extremely low impurity content ensure that the sintering density of MIM reaches 98% of the theoretical density; A variety of specially prepared polymers can not only provide good fluidity during injection, but also ensure efficient degreasing capacity.
4、Injections The MIM feed is heated and evenly filled into the mold cavity by the injection machine, and the MIM injection blank is obtained after cooling. The key to this process is to match the mold that conforms to the characteristics of MIM with the reasonable process
5、Degrease The professional degreasing furnace is used to gradually and efficiently remove the main binder in the injection blank, and the residual skeleton binder maintains the product shape so that the degreased parts can move into the burning stage.
6、Degreasing sintering In the vacuum furnace or atmosphere furnace of MIM, the skeleton binder is removed, and the metal powder is densified into a complete metal body at a temperature close to the melting point. After cooling, the sintered parts with a shape close to the finished product are obtained.
MIM part process advantage 1: extremely high degree of design freedom Compared with other metal forming methods, MIM can manufacture parts with more complex shapes. Basically, all structures that can be realized by injection molds can be applied to MIM	MIM process advantage 2: more material choices MIM can use almost all metal materials. Considering the economy, the main application materials include iron based, nickel based, copper based, titanium based metals or alloys.
MIM process advantage 3: excellent physical and chemical properties Because the sintering density of MIM is very close to the theoretical density, its physical and chemical properties are also very excellent, such as mechanical strength, which greatly exceeds the traditional powder metallurgy. 。	MIM process advantage 4: exquisite appearance The surface roughness (Ra) of MIM sintered billet can reach 1 μ m. It can also obtain dazzling appearance effect through various surface treatment methods.
MIM process advantage 5: higher dimensional accuracy Generally, the tolerance accuracy of ± 0.5% can be achieved with MIM, and higher dimensional accuracy can be achieved with other processing methods.	MIM process advantage 6: powerful and flexible mass production capacity MIM can flexibly adjust and rapidly increase the output, from hundreds of pieces per day to hundreds of thousands of pieces per day.

MIM process advantage 7: environment-friendly processing concept

The utilization rate of raw materials is close to 100%, which is a near net forming technology and can effectively avoid material waste.