Comparison of Porosity of Casts Produced by HPDC and VPDC Technologies

Abstract

The die casting technology enables the production of complex casts with good mechanical properties and high repeatability of the production within narrow tolerance limits. However, the casts are showing signs of porosity to some extent, which may reduce their mechanical and qualitative properties. The presented article solves the problem of reducing the porosity f the high pressure die casts by vacuuming the mold. Under constants technological parameters of casting, series of casts are being casted using the HPDC and VPDC technology. The indirect method of verifying the density and volume of individual samples is used to analyze the porosity of casts. At the same time, a macroscopic examination of the homogeneity of the casts is performed on selected samples. Macroscopic examination showed a detectable decrease in pore size and distribution in the casts. Based on the measurements, i tis proved that by using the vacuum pressure die casting process while maintaining the constant settings of the technological parameters of casting, a reduction in the porosity of the casts by an average of 24.4 % was achieved.