Journal of Alloys and Compounds ( IF 4.175 ) Pub Date : 2018-10-25 , DOI: 10.1016/j.jallcom.2018.10.318 Hua Zhu, Fengming Qin, Huiqin Chen
The effect of an ultrasonic temperature and output power on microstructure and mechanical properties of 6063 aluminum alloy during solidification was investigated by optical microscopy, hardness test, tensile test, SEM. The results showed that compared with the grains in samples without UST, those of under UST are much finer. The grain size approaches to about 80 μm at 750 °C and 600 W and the grain size decreases continuously with falling of test temperature. The grain refinement is significantly affected by temperature than the output power of ultrasonic sound. After UST, the intermetallic phases volume fraction is about 6%, which is much smaller than that (about 11%) of without UST, and no dendrites exsist in the samples after UST. The fracture surface is more uniform without UST, and the reduction of cleavage plane and showing of a typical tearing characteristic demonstrates great improvement of this alloy's mechanical properties.