Cast aluminium degassed without gas
Designed by European small and medium-sized enterprises (SMEs) together with research institutes, degassing by ultrasound provides a safe way to remove gases introduced during the processing of aluminium alloys. H2 is the most common gas that finds its way to the liquid metal through the interface between the melt and atmosphere, forming non-metallic impurities. With EU funding of the project DOSHORMAT (Degassing machine for aluminum casting process based on ultrasound), the team up-scaled already available ultrasonic technology. It had been shown to efficiently degas aluminium alloys at laboratory scale by the previous Seventh Framework Programme (FP7) project ULTRAGASSING. The DOSHORMAT team optimised the method with an eye on mass production. This required adaptation of the ULTRAGASSING conceptual designs for commercial implementation considering all aspects, from manufacturing costs and efficiency to safety regulations and market potential. Moreover, ready-to-market machines for aluminium degassing were developed: one for high-pressure die casting and gravity casting, and another for low-pressure die casting. Extensive tests on the machines in an industrial laboratory allowed researchers to assess different configurations and address specific production aspects. The presence of H2 during the aluminium casting process affects both the melt quality and final product performance. DOSHORMAT succeeded in improving the melt quality, reducing the gas content and enhancing the mechanical properties of aluminium components produced. DOSHORMAT prepared ultrasonic degassing technology for commercialisation through testing in real foundry conditions at participating SMEs. It promises to overcome the limitations of currently used methods (like argon lancing and blasting) relying on mixtures of expensive gases and also contribute to meeting future environmental regulations.
Keywords
Aluminium, ultrasonic technology, moulded parts, degassing, DOSHORMAT, casting process
