Using vacuum induction melting and multi-step copper-mould spraying casting

sub-rapid solidification of magnesium alloy containing SiC inoculants was performed.After isothermal annealing treatment

compound effects of cooling rate and inoculant content on the grain size of spraying deposited magnesium ingots were investigated.Experimental results show that microstructure of the copper-mould quenched magnesium alloy exhibits fine particle

which changes into equiaxed grain with polygon morphology after solid solution at 400 ℃for 2h.Cooling rate is enhanced with decreasing the inner diameter of copper-mould

resulting in the increase of effective nucleation fraction with uniform distribution and decrease of grain size.With addition of 2% SiC and inner diameter of 4mm

the minimum grain size reaches 4μm

and whole fine grain casting can be realized.