ULTRAGASSING · DEVELOPMENT OF A DEGASSING SYSTEM FOR ALUMINIUM CASTING PROCESSING BASED ON ULTRASOUND

Light alloys play the main role in vehicles weight reduction and in the last years the amount of aluminium parts in new vehicles has been steadily increasing. Moreover, weight is even a more critical factor in newly developed electric and hybrid vehicles, as it highly affects their autonomy. The global green house savings from the use of aluminium in vehicles is expected to double by 2025.The use of aluminium alloys is however limited by the quality and insufficient properties of the cast parts that suffer from gas porosity.The presence of hydrogen in the molten metal is the mainly reason of gas porosity in high performance components, which is currently dealt with by melt degassing techniques that involve purging of gas mixtures (often containing chlorine and fluoride) through the melt. This technology is expensive, has limited efficiency and poses health hazard.Previous research demonstrated that treating the liquid metal with ultrasound highly reduces the concentration of hydrogen, improving the quality or the cast parts and increasing the efficiency of some existing degassing techniques when combined with them. The known demonstration of the efficiency of ultrasound-aided degassing has been done on laboratory and pilot scale, and not in the mass production of cast components.The Ultragassing Project intends to define a method to apply the ultrasound degassing treatment in light-alloys foundry (most of foundries are SMEs), providing the foundry with the environmentally friendly and safe means to improve the quality of cast parts.During the Ultragassing Project the link between parameters of ultrasonic degassing, melt quality and casting parameters will be established, which will allow the development of versatile technology that can be finely tuned to the specific casting process. This new degassing technology based on ultrasound will be validated and compared in performance with the currently used ones.""