Optimization of the High Pressure Die-Casting Process to Reduce Porosity
DOI:
https://doi.org/10.24425/afe.2026.157985Abstract
The main problem with the use of pressure castings from aluminium alloys for, among others, critical parts in the automotive industry is the presence of porosity. Obtaining castings with reduced porosity is a very difficult task, requiring a number of changes in relation to the classic pressure casting process. This basic defect limits the area of application of pressure castings. In addition to reduced tightness and inadequate external surface quality, it can reduce the strength and/or plastic properties of the castings. One of the solutions to avoid problems in the production of high-quality, tight and at the same time thin-walled and durable castings from Al alloys can be the use of a special high-pressure casting solution using the so-called "vacuum". The use of the Vacuum system in high pressure die-casting can significantly reduce the porosity of castings. The amount of gas present in the pressure casting is influenced by the geometry of the part and the process parameters. At standard temperature and pressure, the gas content inside die-cast parts typically ranges from 10 to 50 cm3/100 g. Using vacuum casting, gas content below 10 cm3/100 g, or even 1 cm3/100 g, can be achieved, allowing simplified heat treatment and welding of the parts.
The article presents selected studies on reducing porosity in pressure castings using the Vacuum system. Microstructural tests, density tests, X-ray and CT, and a leak testing of the castings were carried out.
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