Continuous fluxless recycling of high purity magnesium die cast alloys

摘要

With the rapid growth of magnesium die casting applications in automotive industry, recycling of magnesium scrap has become an increasingly important issue. Meridian Magnesium in co-operation with Norsk Hydro has recently developed and implemented a continuous fluxless process for recycling Class 1 magnesium die casting scrap. This innovative and environmental friendly process is designed to refine AZ91D and AM60B magnesium scrap from Meridian's die casting plants to high quality ingots for die casting production. Extensive tests were carried out on liquid metals, recycled ingots and die cast specimens, respectively. Results show that Meridian's recycled ingots and their castings have qualified chemical compositions according to ASTM specifications. The liquid metals refined by Meridian's recycling process contain low oxide content. The recycled ingots have low oxygen and chloride contents. The casting specimens from both recycled and primary metals have equivalent mechanical properties and corrosion resistance. It is concluded that Meridian's recycling process can produce high quality magnesium ingots. This paper discusses the overall quality of Meridian's recycled AZ91D and AM60B metals.