The influences of different preheating temperature of mold and treatment temperature on solidified structure of LC9 alloy were studied by low-power ultrasonic vibration melt-treatment. The results show that grain of LC9 alloy can be refined greatly by low-power ultrasonic vibration melt-treatment. The dendrite growth is restrained and the microstructure is changed from larger dendrite grains to dominant fine none-dendritic and globular grains. With the decrease of preheating temperature of mold, grain size decreases. The efficiency of grain refinement is better at low preheating temperature. With the increase of ultrasonic vibration temperature, grain size decreases firstly, then increases, and the turning point is 660 °C. At 640 °C, grain size of the alloy with US vibration treatment changes slightly compared with non US-treated alloy.
Design of Low-power Ultrasonic Anemometer Based on STM32L476