Numerical Simulation And Craft Researching Of Shelling Part Die Casting Filling And Solidification Process

Pressure casting, as a special casting method, has been widely used in aerospace, automotive, machinery, hardware, toys, electronics, handicrafts and other fields, for its high dimensional accuracy, excellent mechanical properties, higher productivity, less allowance or no allowance and other characteristics. However in the traditional die casting industry, casting process parameters can usually only be determined by experience and technical personnel, lack of a unified theoretical guidance, leading to the scrap rata of die castings are relatively high and financial and material resources are spend too much. Currently, in order to improve efficiency and cost savings, three-dimensional modeling software for mold design and die casting process simulation are widely used in the die casting industry not only to analyze the filling and solidification conditions during the pressure casting, but also to forecast the location and size of casting defects in the pressure castings so as to select the best simulation result which has least defect in the casting. The results of applying the optimized process parameters obtained by simulation into production further verify the reliability of the simulation results. Thus, simulation on die casting process can not only lower scrap rata for companies avoiding unnecessary economic losses, but also upgrade competitiveness of enterprises in the market.The die casting investigated in this paper is outer casing of the gas meter, produced by a factory in Shenyang. The internal structure of the casting is very complicated not only with a cavity inside the casting, but with a circular hole and the groove in the front end of the casting. Many casting defects like internal shrinkage and hole were found in the castings produced by the original process and the product was failed to suppress, resulting in a higher rejection rate. Therefore, this paper redesigned the gating system using the three-dimensional software and optimized process parameters of die castings through numerical simulation aiming to reduce inner defects.During the test, for the purpose of reducing the shrinkage and hole in die castings, three inner gate plans were designed according to the theoretical value of the gate and the optimized inner gate plan was certificated by simulation software Procast. Through orthogonal tests, the effect of injection speed, mold preheating temperature and alloy pouring temperature on the variation of the liquid metal flow field and temperature field during the solidification in the die casting process was analyzed and researched by adjusting the three forward process diameters. Optimized process parameters are as follows: the alloy pouring temperature is 620℃, injection speed is 5m/s and mold preheating temperature is 200℃.This paper analyzed and investigated the filling and solidification process in shelling part die casting. The factors that caused defects were identified and solution plans were put forward by improving die casting parameters so as to apply the simulation results into production smoothly to obtain die casting with good quality.