VACUUMING OF THE DIE MOLD AS A FACTOR FOR IMPROVING THE TIGHTNESS OF ALUMINUM ALLOY CASTINGS IN PRESSURE DIE CASTING

Abstract

The article presents the results of a comprehensive experimental study on the influence of mold vacuuming on the tightness of aluminum alloy castings produced by pressure die casting. The dependence of internal defect formation, including porosity, gas inclusions, and misruns, on the level of residual pressure in the mold cavity prior to melt injection was analyzed in detail. It was established that reducing the pressure to 80–100 mbar significantly decreases the likelihood of defect formation, particularly in thin-walled components, which is critically important for ensuring the reliability, strength, durability, and operational stability of the castings. Experimental investigations were carried out on modernized industrial casting equipment equipped with an integrated vacuum system, digital realtime monitoring of pressure and temperature, and adaptive control of technological parameters, ensuring process stability and precise control of all casting parameters. The study demonstrated that the application of vacuuming reduces the proportion of defective castings from 7.2 % to 2.9 %, providing uniform mold filling without air pockets or surface defects. The combination of vacuum mode with digital process control promotes the formation of a dense microstructure with minimal porosity and enhances the tightness, mechanical performance, and reliability of castings, especially complex structural components with high-quality requirements. The results confirm the effectiveness of integrating vacuum equipment into the industrial die casting process as a reliable, economically feasible, and technologically justified approach to improving product quality, stabilizing the production process, and ensuring high dimensional accuracy of serially manufactured components.