Effects of ultrasonic field on the Pb‐Sn alloys during heating process

In this work, the effects of ultrasonic field on the Pb‐Sn alloys during heating process have been discussed using electrical resistivity and thermal curves. The semi‐solid and liquid alloy have different resistivity responses to ultrasonic irradiation, due to ultrasound irradiation only available to liquid phase. Sensitive structural change by ultrasound can be only found in the liquid state, according to the resistivity drop and thermal curves. It might be due to the low volume fraction of liquid phase at initial stage and the fast solid‐to‐liquid transitions at the final stage. Ultrasound can also trigger the nucleation and growth of liquid phase, through driving the melting of solid phase at solid/liquid interface and transferring into the liquid phase. The concerned mechanisms have been discussed in detail.