Contactless electromagnetic method for aluminium degassing

Degassing of aluminium alloys is an important technological step. In this work the idea and mathematical, and numerical description of electromagnetic aluminium degasser is presented. Experimental electromagnetic device for degassing aluminium alloys is designed and tested to estimate the feasibility of this technology. Degassing is a technological intermediate step in the production of aluminium between the melting and casting of the metal. Mainly hydrogen has been dissolved in liquid aluminium because of reaction with water vapor. To prevent the formation of pores during casting, hydrogen is removed - the liquid metal is degassed. Typically, degasification is achieved by injecting an inert gas in the metal, usually argon, which binds to hydrogen bubbles. For the industrial process to be more efficient, the size of the argon bubbles must be as small as possible. At present, the most widely used method to refine bubbles is to place a mechanical rotor inside the liquid metal. Although such mechanical bubble shredding fulfils the task, it also has significant disadvantages, hence alternatives are being sought.