Pore-die-casting - a way to save aluminum?

Die casting is an established casting process for the production of cast parts from low-melting alloys in large quantities. The process is characterized by a high degree of automation and allows the production of near-net-shape castings with high dimensional accuracy and repeatability. In order to manage the casting process effectively and to design the die casting tool optimally, casting process simulations are already carried out in the planning phase in order to obtain information on the mold filling and solidification process, microstructure formation, residual stresses and distortion of the cast parts before casting.
The aim of process control is to achieve complete mold filling in the casting process with minimal use of material in order to achieve the desired properties of a die-cast part. This is particularly important for die-cast parts that have to withstand defined loads. These include engine and gearbox housings, for example. For other cast parts such as covers for appliances or switch cabinets, however, the requirements are much lower. Here, the focus is on protecting the electronic/electrical components from dust and dirt and protective measures against electric shocks through contact.
The article takes up the idea of reducing the material input of cast parts that are not critical in terms of their mechanical target properties to below the shot weight usually aimed for. The pore pressure casting process is used for this purpose. The aim of the process is to achieve material savings through controlled adjustment of the casting porosity without impairing the casting quality and functionality. The process thus opens up the possibility of saving weight in the end products and using resources more efficiently.The article presents tests on the production of cast parts using pore pressure die casting and various process parameters. The tests were planned and evaluated using the Cornerstone statistical software. The test program was based on a D-optimal test plan. The results achieved in the casting tests - including casting weights, surface qualities and tensile strengths of the castings as well as X-ray images - are discussed and evaluated.