Effects of high pressure die casting parameters on porosity formation in aluminium casting parts

Aluminum alloys have a high usage rate, especially in the aviation, defense and automotive industry, where weight reduction is extremely important. Pressure die casting technology is a widely used method of casting aluminum alloys in terms of its suitability for mass production. Aluminum-silicon alloy parts produced by the high pressure casting method (HPDC) generally contain porosity in different proportions and sizes due to the discharge problems of gases trapped during the rapid injection of molten metal into the mold cavity. Due to the worsening of reliability expectations and customer specifications in the casting industry, it is desired to reduce gas porosity levels to certain critical levels. Proper mold design and optimization of casting process parameters play an important role in reducing gas porosity by facilitating the evacuation of air from the mold cavity. In this study, porosity values before and after degassing for three different alloys (AlSi9Cu3, AlSi12Fe and AlSi12Cu1Fe) were compared. In addition, for the AlSi9Cu3 alloy, four different (150, 200, 250 and 300 bar) pressures were applied to produce water pump body through cold chamber high pressure casting method and, the porosity values were measured and compared.