The formation process of cast aluminium components during casting
2026-01-23
Aluminium casting frequently encounters oxidised inclusions, with the majority of these impurities dispersed across the surface of the castings. Some occur in areas inaccessible to simultaneous turning, appearing yellow or greyish-white due to excessive porting. This becomes evident during machining and can be traced to causes identified during acid or alkaline pickling:
Insufficient purity of furnace materials; excessive use of recycled scrap; poorly designed pouring systems; inadequate removal of dross from the molten aluminium alloy, potentially entrained during pouring due to improper techniques; prolonged holding time after modification treatment.
To effectively resolve these issues, we must: - Maintain a controlled casting speed to minimise entrapped gases; - Ensure core sand is free from organic contaminants to reduce gas evolution; - Enhance core sand's venting capabilities to improve casting performance; - Select appropriate chill blocks and rectify casting system design flaws.
