Abstract:A semi-solid microstructure of ADC12 aluminum alloy containing spherical solid particles was studied. A new strain-induced melt activation (SIMA) process was proposed. In the treatment, chips were cut from ADC12 ingot by lathe machining and the plastic deformation was produced through cutting. The chips were put into a metal mold and compressed into a billet at 473 K. The microstructures of chip and billet were studied. The effect of the isothermal treatment on the semi-solid microstructure evolution of ADC12 aluminum alloy prepared by the new method was analyzed. A series of heating treatments were carried out from 823 to 838 K. The effects of heating temperature on microstructures were studied. The experimental results show the ADC12 aluminum alloy prepared by the new method can reap homogeneous and spherical grains at 828 K. The average grain size is about 82 μm. Also, the grain microstructure obtained by the present process is better than the traditional one. These results prove that the ADC12 aluminum alloy can be applied to semi-solid processing with the new SIMA method.

Key words: ADC12 aluminum alloy; semi-solid; microstructure; strain-induced melt activation