Metal injection molding MIM3C smart product accessories

Product Details

MIM技术起源于一些欧洲国家，最初是军事装备组件的开发和应用。通过，在中国长江三角洲地区发布MIM技术，经过不断的探索和实践，已成功组装汽车零部件，3C数字产品，医疗设备，工具锁等众多热门领域。上。

01

总览

金属粉末注射成型技术（MIM）是一种新型粉末冶金近净成型技术，是通过将现代塑料注射成型技术日期粉末冶金领域而形成的。这是一种将金属粉末及其粘合剂的增塑单一注射模具的成型方法。

点击查看图片评论

02

工艺流程

MIM制造过程通常包括：混合和造粒，注塑，脱脂，烧结和二次处理。将注塑设计的对准与精密金属的高强度和定向相结合，适用于批量生产小型，精密，复杂形状以及具有特殊性能要求的金属和陶瓷零件。具有广阔的应用前景和经济价值。

（1）混合：将金属细粉，热塑性塑料和石蜡混合物按精确比例混合。将其在特殊的混合设备中混合并加热至一定温度以熔化粘合剂。在大多数情况下，使用机械混合直到金属粉末颗粒被粘合剂均匀地涂覆并冷却以形成颗粒状原料为止。

(2) Molding: The equipment and technology of injection molding are similar to those of injection molding. The raw materials are fed into the machine to be heated and injected into the mold cavity under high pressure. This link is formed (greenpart) and demoulded after cooling. Only when the binder is melted (fully fused with the metal powder) at a temperature of about 200°C, the entire process described above can be carried out. The cavity size design should consider the shrinkage produced during the sintering process of metal parts.

(3) Degreasing: Use physical or chemical methods to remove the binder from the parts, the most commonly used is solvent extraction. Most of the binder is removed before sintering, and the remaining part can support the component to enter the sintering furnace and be volatilized during sintering. The parts change from the mixture of metal powder and binder to pure metal parts, the volume shrinks, and the shape and structure remain unchanged.

(4) Sintering: The parts are put into a furnace controlled by high temperature and high pressure. The part is slowly heated under the protection of gas to remove the remaining adhesive. After that, the part is heated to a very high temperature, and the voids between the particles disappear due to the fusion of the particles. The part shrinks directionally to its design size and transforms into a dense solid. The volume shrinks further and the shape and structure remain unchanged.

In view of the shrinkage and deformation of product parts during injection molding and sintering, the following problems need to be solved:

1. Directly observe the overall size change law of the product parts during the sintering process and the local bending deformation law of the parts affected by gravity;

2. The non-contact measurement method is adopted to avoid the influence of the loading force of the contact measurement ejector pin on the debinding and sintering deformation;

3. The large-area measurement method is used to directly test the deformation of the molded part to avoid insufficient representativeness of the sample preparation;

4. Realize simultaneous measurement of two-dimensional deformation of molded parts or specimens, and have the function of simultaneous measurement of multi-point position changes;

5. Observe the changing law of component size under different heating systems (such as different heating and cooling speeds and different constant temperatures);

6. Observe the influence of different atmospheres (vacuum, argon, nitrogen, hydrogen, etc.) and different pressure conditions on the dimensional changes of parts, as well as the influence of switching atmosphere conditions and constant pressure in different temperature intervals on the dimensional changes of parts;

7. At the same time, it has a high-precision high-temperature thermal expansion coefficient test function.

(5) Surface treatment: Commonly used surface treatment processes for MIM parts include polishing treatment, electroplating treatment, PVD treatment, blackening treatment, phosphating treatment, spraying treatment, etc.

03

MIM process characteristics

1. High degree of freedom in the geometry of the parts. It can produce metal parts with complex shapes at one time like plastic products, with uniform density and high dimensional accuracy. It is suitable for manufacturing complex geometric shapes, precision and special requirements. Small parts (0.05g-200g);

2. The alloying flexibility is good, and the manufacturing cost can be reduced for materials that are too hard, too brittle, and difficult to cut, or parts with segregation or contamination during the casting of raw materials;

3. The product quality is stable, the performance is reliable, the relative density of the product can reach 92-98%, the product strength, hardness, elongation and other mechanical properties, good wear resistance, fatigue resistance, and uniform organization. Carburizing, quenching, tempering, etc. can be processed;

4. The product cost is low, the finish is good, and the accuracy is high (±0.3%～±0.1%), the typical tolerance is ±0.05mm, generally without subsequent processing;

5. The utilization rate of raw materials is high, the production efficiency is high, the production automation is high, the procedure is simple, and it can be produced in large quantities continuously and on a large scale.

04

MIM application field

The application of MIM is extremely wide.

(1) Automobile parts: parts for airbags, parts for automobile locks, parts for seat belts, automobile door lift systems, pinions, small parts for automobile air conditioning systems, racks in brake systems, etc., sensors in fuel supply systems Small parts in

(2) Military parts: gun parts, ammunition parts, fuze parts;

(3) Computer and IT industry: such as mobile phone card holders, mobile phone structural parts, printer parts, magnetic cores, firing pin shaft pins, driving parts, optical communication ceramic plugs;

(4) Tools: such as drill bits, cutter heads, nozzles, spiral milling cutters, pneumatic tools, fishing gear parts, etc.;

(5) Household appliances: such as watch cases, bracelets, electric toothbrushes, scissors, golf heads, jewelry links, cutting tool bits and other parts;

(6) Parts for medical machinery: such as orthodontic frames, scissors, tweezers;

(7) Electrical parts: micro motors, sensor parts;

(8) Mechanical parts: such as textile machines, crimping machines, office machinery parts, etc.

05

Process comparison

Comparison of MIM and CNC:

Same: Both are suitable for producing products with complex three-dimensional structure and high precision requirements.

Differences: 1. Cost of complex parts: When the product complexity is extremely high, CNC calculates the price on time, and the cost is higher than MIM;

2. Production of ultra-small parts: CNC is restricted by the blade and cannot produce ultra-small parts, but MIM is suitable for the production of small parts;

3. Production of ultra-thin parts: CNC is subject to clamping, and products with a wall thickness of less than 1mm are easy to deform, and MIM can produce ultra-thin parts;

4. Mass production: CNC production efficiency is high for small batch production; MIM production efficiency is high for mass production.

CNC and MIM are not entirely a substitute relationship, but also have a complementary relationship. For example, there is a CNC process in the post process of MIM.

06

MIM future development

Industry representatives include Shanghai Fuchi High-Tech Co., Ltd., which is currently the leading enterprise with the largest production scale and the most advanced equipment in China, and has also trained a large number of MIM technical personnel; and Changzhou Jingyan Technology Co., Ltd., the first domestic listed company MIM business representative.

Although MIM is attracting more and more attention, its scale is still weak compared with traditional processing technology, and it has great development potential. The nascent MIM industry also needs a series of efforts to develop industrial standards, accelerate industrialization, improve the quality of practitioners, research and develop equipment, and win customers to develop it.

(1) Diversification of binders and multi-channel degreasing technology

Many binder systems based on cellulose acetate, polyethylene glycol polymer, acrylic polymer, and agar have been further developed and applied. Computer-aided control thermal degreasing technology, solvent degreasing technology, catalytic degreasing technology, freeze-drying technology, microwave-assisted drying technology are all used in the degreasing research of binders.

（2）更先进，更精确的控制设备

计算机精确控制的注塑机和相关的在线质量监控系统的研究以及计算机辅助除油关键设备技术的发展是当前和未来的重点方向。

（3）产业必须形成相关产业链

只有透彻了解技术和工程能力，形成生态产业链，将产业链结合起来，才能抵御风险，加快发展。