Grain and Microstructure of Cast Mg AZ31-B Alloy Produced by the Magnetic Suspension Melting Process

摘要

Magnesium is the lightest of all structural metals and offers significant weight savings compared to traditional automotive materials. One of the processing difficulties of such a reactive metal is contamination of the alloy with oxides during melting. This paper describes macro/microstructure of cast Mg AZ31-B alloy using the Magnetic Suspension Melting (MSM) at a low superheat of 5oC. Metallographic examination of the MSM cast alloy shows no evidence of oxide formation. It was also found that casting at this low superheat produce fine cellular grain structure compared to the dendritic structure in conventionally cast alloys. The intermetallic phases were analyzed in detail and compared with the conventionally cast alloy.