MIM Technology in Production of Tungsten Heavy Alloys

Metal Injection Molding (MIM) is a new PM molding technology which is extended from the injection molding of plastic industry. As well knowned, plastic injection molding can make various products with complicated shapes but the strength is not very high. To improve its performance we can add metal or ceramic powders into it to get products with higher strength and more wearable. In recent years, this idea has evolved to maximize content of the solid particles and in the subsequent sintering process to completely remove the binder and forming the blank with good densification, and finally get a metal part. This new PM molding method called MIM.
 
Metal injection molding technology has unique advantages in the manufacture of complex shapes, uniform organizational structure and high precision net shape products. Any metal or alloy in powder can use this method to manufacture parts. Besides, this technology can be fully automated continuous operation, high productivity and material utilization is almost 100%. Tungsten alloy parts are widely used in military, medical and scientific laboratory equipment etc. As technology advances, the various application sectors for high-density tungsten alloy parts requires more complex shapes, processing more and more difficult, the production costs is very high. And metal injection molding technology can solve this problem. Due to the small size of tungsten powder produced by traditional methods, using MIM technology doesn’t need additional powder cost. Compared to injection molding low alloy steel, stainless steel and other materials, it has a unique advantage in raw material costs.
 
Tungsten heavy alloy parts can be produced by powder metallurgy only. Due to its high strength and hardness, the mechanical processing after sintering is very difficult. And for parts with big length or diameter, density can be not even during the pressing which cause the deforming and size difference after sintering. MIM technology can not only form a complicate part blank at one time, but also can avoid the density difference during the pressing. Since MIM is invented and developed, it has been used for production of different tungsten alloy parts.
 
Metal injection molding technology because of its enormous advantages in technical and economic terms, from the late 1970s and early 1980s, since the advent of very rapid development, and its products have been widely used in national defense and civilian fields. In many applications, tungsten heavy alloy is one of the important products.
 
In the near future, with the further development of MIM technology. China's high-density tungsten alloy industry will be applied to more and more of MIM parts.