Application Effect of Self-made Covering Flux in Melting Cerium-Containing AZ91D Magnesium Alloy

A new kind of covering flux with the functions of modification and anti-oxidation was developed.The effect of self-made covering flux NRJ on as-cast microstructure and mechanical properties of the melting cerium-containing AZ91D magnesium alloy was analyzed by using thermal analyzer,optical microscopy,mechanical property tester and XRD.Then it was compared with the coventional covering flux RJ2.The results show that the Mg17Al12 phase in the alloy after melting with NRJ as covering flux were refined.The nuclear particles of A14C3 were formed in the grains and promoted the matrix grain refining.The tensile strength,yield strength and elongation of the alloy were increased by 36%,32% and 146%,and the tensile fracture had more and deeper dimples.The oxidation resistance properties of the alloy were better than those of the alloy melted with conventional covering flux RJ2.