Abstract:

             This paper addressed the effects of Al6.53Ti0.3C0.46B master alloy (Ti∶[KG-*2]C＞4∶[KG-*2]1) on the microstructure and mechanical properties of high aluminumzincbased alloy. Experimental results show that the addition of the master alloy can significantly refine the microstructure of the high aluminum zinc based alloy. The shape of a primary α phase grain changes from coarse dendrite into fine and uniform equiaxed crystal. The average size of equiaxed crystal is 30~50 μm. The extension rate of the alloy increases from 1.7% to 10.0% and the tensile strength is about 410 MPa in the condition of sand casting (SC). The extension rate of the alloy increases from 1.0% to 16.0% and the tensile strength is about 407 MPa  in the condition of permanent mold casting (PMC). Its tensile strength does not significantly increase though its microstructure is obviously refined. Its refinement mechanism is the increase of heterogeneous nucleus due to the addition of Al-Ti-C-B master alloy.

Key words: zinc based alloy, zinc aluminum alloy, Al-Ti-C-B master alloy, modification, refinement