Introduction to the technical features of metal injection molding!

Introduction to the technical features of metal injection molding!

Metal injection molding is a molding method to inject the plasticizing mixture of metal powder and its adhesive into the mold. It is to mix the selected powder with the binder, then granulate the mixture, and then inject it into the desired shape. The polymer gives the mixture viscous flow characteristics, which is conducive to the uniformity of molding, cavity filling and powder filling. After molding, the binder is removed, and then the degreased green body is sintered. Some sintered products may require further densification, heat treatment or mechanical processing. The sintered products not only have the same complex shape and high precision as plastic injection molding, but also have physical, chemical and mechanical properties close to the forging. This technology is suitable for batch production of small, precise and complex three-dimensional metal parts with special performance requirements.

Metal injection molding is a new powder metallurgy near-net forming technology that introduces modern plastic injection molding technology into the powder metallurgy field. Metal injection molding is widely used in consumer electronics, auto parts, hardware tools and other fields. In the 3C industry, it is regarded as the synonym of the iPhone holder, camera ring metal protective frame. In the recent two years' hot electronic cigarette industry, metal injection molding processing is also used in its precision parts.

Metal injection molding is an engineering technology, which involves converting plastics into useful products that can maintain the original performance. The important process conditions of injection molding are the temperature, pressure and corresponding action time that affect the plasticizing flow and cooling. The temperature control of the barrel is very important. The temperature to be controlled during the injection molding process includes the barrel temperature, nozzle temperature and mold temperature. The first two temperatures mainly affect the plasticization and flow of plastics, and the last one mainly affects the flow and cooling of plastics. Each plastic has different flow temperatures. Due to different sources or brands of the same plastic, the flow temperature and decomposition temperature are also different. This is because of the differences in average molecular weight and molecular weight distribution. The plasticizing process of different models of injection molding machines is also different, so the barrel temperature is also different.

What are the technical characteristics of metal injection molding? Now let's analyze it together.

1. The production of small metal parts with complex shapes similar to plastic products is suitable for manufacturing small parts with complex geometric shapes, high precision and special requirements, usually weighing (0.2-200g).

2. Thin-walled structural parts can be directly formed. The shape of the product is close to or meets the requirements of the product. The dimensional tolerance can generally be maintained at 0.10%~0.30%.

3. Compared with traditional machining and precision casting, the internal structure of the product is more uniform; Compared with traditional powder metallurgy press sintering, this product has better performance, high dimensional accuracy, good surface finish (surface roughness can reach Ra 0.80~1.6 μ m), and requires no further processing or only a small amount of finishing.

4. These materials are widely used, including ferroalloys, superalloys, titanium alloys, copper alloys, refractory metals, hard alloys, ceramics and metal matrix composites. The product density is high (up to 95%~99%), the structure is uniform, and the performance is excellent. They can be subject to carburizing, quenching, tempering and other heat treatment.

5. The product has uniform microstructure, high density, strength, hardness, toughness, plasticity and other mechanical properties, stable product quality, high production efficiency, and can realize automatic, large-scale and large-scale production.