The metal injection molding industry is changing rapidly, and recent advances have expanded the scope of MIM technology. Parts can be cast into more complex shapes, wider size ranges, tighter tolerances with a variety of alloy options.
The advantages of metal injection molding mechanical polishing are good flatness and high brightness. Mechanical polishing is a method of polishing a smooth surface by cutting and plastic deformation of the surface of the material, usually using stone strips, wool wheels, sandpaper, etc., and is mainly done by hand. Special parts such as external rotation, use of turntables and other auxiliary tools can be ultra-precisely polished to obtain a high-quality appearance. Ultra-fine grinding and polishing use special grinding tools to rotate the machined surface at high speed. This method is usually used in optical lens molds by metal injection molding factory.
Chemical polishing for MIM injection molding has the advantages of low investment in processing equipment, large throwable parts, high speed, high efficiency, and good corrosion resistance. Chemical polishing is to make the convex surface in the chemical medium dissolve before the concave surface to obtain a smooth surface. The important advantage of metal injection molding chemical polishing is that there is no complicated equipment, and it can polish complex shapes and multiple workpieces at the same time, with high efficiency. The key issue of chemical polishing is the preparation of polishing liquid.
Metal injection molding parts of ultrasonic polishing is placed in an abrasive suspension, together with an ultrasonic field, and ultrasonic vibration is applied to grind and polish the surface of the abrasive. Ultrasonic processing has the characteristics of small macroscopic force and no deformation, but it is difficult to manufacture and install molds. Ultrasonic processing can be combined with chemical or electrochemical methods. On the basis of solution corrosion and electrolysis, an ultrasonic vibration solution is used to dissolve the surface of the workpiece. Ultrasonic cavitation in the liquid can also inhibit the corrosion process, which is conducive to a bright appearance.
Magnetic grinding is the use of magnetic abrasives and abrasive brush under the action of a magnetic field to grind the workpiece. This kind of processing has high efficiency, good quality, easy control of processing conditions, and good working conditions. At present, the main polishing methods for metal injection molded stainless steel parts are magnetic grinding and mechanical polishing.