The low super heat processing and semi-solid thixo-casting processing are adapted to fabricate the AZ91D magnesium alloy generator’s brackets in JH70 motorcycle in die casting machine successfully.The experimental results shows that the unmelted α-Mg phase in the semi-solid casting and semi-solid casting with heat treatment samples

which has no void and shrinkage

is thin

and scatteredon the α-Mg17Al12 eutecticphase uniformly.Comparing with the semi-solid sample with heat treatment

the hardness and tensile strength of the sample with T4 heat treatment degrade about 4.5% and 3.1% respectively

and those with T4 heat treatment increase about 30.1% and 14% respectively

furthermore

the elongation of the sample with T4 and T6 heat treatment increases 17.6% and 40.5% respectively.