NONMETALLIC INCLUSIONS IN THE SECONDARY ALUMINUM INDUSTRY FOR THE PRODUCTION OF AEROSPACE ALLOYS

Due to enormous growth of the secondary aluminum industry and the required increase in melt quality, the development of methods for inclusion removal has become highly important. To produce high quality aerospace alloys with very low inclusion contents, casthouses must analyze and optimize their production processes from the beginning to the end. Nowadays, there are several methods available for process evaluation and the determination of inclusion level from one step to another. Furthermore, the most important parameters for control of the final inclusion level have to be investigated. This paper characterizes the change of the inclusion content for the alloy AA 7075 during standard casthouse processing. The possibilities for the improvement of the melt quality are also discussed.