The Equipment Improvement And Process Exploration Of Semi-Solid Magnesium Alloy Injection Molding

Because of its low density, high specific tenacity strength and specific stiffness, strong electromagnetic shielding capability and is easy regeneration, abundant reserves, and so on a series of unique merits, magnesium alloys have become the unreplaceable material of the the three pillars industries, such as automobile, telecommunications, aerospace. However, the melting magnesium has a strong affinity with oxygen, and in addition a high steam tension, which has become the problem to control safety in production magnesium alloy in the production of conventional die-casting. While injection molding process of semi-solid magnesium alloy is a good solution this problem, the spherical semi-solid structure has the required high performance for forming, that is, rheology and thixotropy. Semi-solid magnesium alloy injection molding is a realization of commercial production of semi-solid processing technology, and it is highly competitive for the semi-solid metal forming technology in the production of near net-shaped parts, which has opened up new prospects.The paper mostly expatiates on the technical theory of semi-solid magnesium alloy molding and equipment. The machine alteration of plastic injection is designed and researched based on the parameters of magnesium alloy semi-solid injection machine produced by Japan Steel Work. The major parts of altering the plastic injection machine with 200g content into Magnesium Alloy Semi-solid Molding machine is two parts. The first one is altering the heating system, the other is screw shear system.The raw material for injection forming is the magnesium alloy AZ91D scrap. Barrel's temperature is controlled between 580℃and 610℃. Opt the intermediate frequency induction heating, with frequency is 1500～2400Hz according to the computation. The intermediate frequency power equipment uses the silicon-controlled rectifier intermediate frequency installment, meanwhile designe and process the induction coil. In order to make the heater work normally without the influence of high temperature, water-cooled device is designd and machininged according to academic calculation.The key part to alter the plastic injection machine is how to improve the screw's structure.The screw's strength and strecture of plastic injection machine can not meet what the high temperature of magnesium alloy semi-solid injection conditions. According to available information and semi-solid magnesium alloy injection molding, the processing parameter and technology of screw are designed in this paper to meet the magnesium alloy semi-solid injection conditions. The screw material is H13 (4Cr5MoSiV1), the processing craft is, forging, spheroidizing, roughing, rough milling spiral flute, half fine mill spiral flute, step quench, tempering, correct grinding spiral flute, polishing, non-nitriding place tin-plating protection, nitriding, finishing processing.The main technological parameter of semi-solid magnesium alloy injection is formulated as follows, barrel temperature, screw speed, mold temperature and injection speed. Introduce the impact on the semi-solid organization of injection molding process parameters. Then carried out injection trials, explored the molding ability and optimized them according to technological parameter's hypothesis principle.