Comparison of liquid metal cleaning methods used in casting of aluminum alloys

Aluminum and its alloys are among the most widely used engineering materials in modern industry due to their lightness, high strength/weight ratio, excellent corrosion resistance and superior recyclability properties. Aluminum can be produced from primary sources or recycled materials. The use of recycled aluminum provides significant advantages in terms of both sustainability and cost. However, it may contain undesirable elements such as impurities, oxide layers, inclusions and hydrogen gas that affect the overall performance of aluminum. Removal of these impurities through liquid metal cleaning methods is of great importance in aluminum casting processes. In this study, an experimental investigation was conducted on the effectiveness of different liquid metal cleaning methods used in the casting of aluminum alloys. In this context, molten A356 alloy from the scrap was cast by applying liquid metal cleaning by flux, fixed lance, and rotary type degassing methods. Then, samples were produced by using the reduced pressure test (RPT), the K-mold, spiral fluidity, and mechanical test molds in casting experiments. The effectiveness of each method in removing inclusions and gases from the liquid metal was evaluated by microstructure analysis, mechanical tests, density measurements, and fluidity tests. As a result of the study, it was determined that the rotary type degassing method was more effective in liquid metal cleaning processes compared to the flux and fixed lance methods.