Effect of flux on in-situ melting shell investment casting of AZ91D magnesium alloy

In this research, the effect of flux on investment casting of AZ91D magnesium alloy using in-situ melting technique was investigated. AZ91D granules together with different flux percentages and applications were charged into shell investment moulds and heated at 750 °C in argon protected environment in order to produce AZ91D investment casting. Surface of castings and the occurred mould-metal reaction was analysed. It was found that application of flux together with the granules is essential to produce a solid investment cast alloy. The results showed that usage of flux mixed with the granules as well as covering the granules on top with a layer of it produced the higher surface quality casting. Microscopic examinations revealed that flux developed a barrier layer which reduced mould-metal reaction and contributed to an improved approach in magnesium alloys investment casting proces