.15 Khz Ultrasonic Casting Vibration System Design And Testing

Power ultrasonic has special acoustic characteristics which can greatly change the properties of physics,chemistry,biology of substances, or expedite such changes. Treating aluminum melt with power ultrasonic can improve solidification structure and mechanical properties of metals obviously. It is the international research hotspot nowadays and a new developing direction of technology of aluminum alloy casting. Taking the 7050 aluminum alloy ultrasonic casting as research object, the main study of the paper was done as follows:1.Combined with the characteristic of the casting, the longitudinal oscillation equation of ultrasonic horn with random variable cross-section was discussed. The physical and mathematical models were established. Based on the above, by choosing appropriate material and size, the main structures of ultrasonic vibration system of 15 kHz were designed.2.The computer simulation of the new designed ultrasonic vibration system was performed by employing the FEM software ANSYS, through which the resonance frequency, vibration displacement modes and distribution of amplitude were acquired. The new designed ultrasonic vibration system was tested through the laser Doppler vibrometer, which proves the resemblance with the theory and FEM.3.The output power of ultrasonic vibration system was obtained by experiment. The rule of the effect of ultrasonic vibration in liquid was studied by water simulation experiments.7050 aluminum was treated with ultrasonic vibrations of 15 kHz and 20 kHz respectively by dipping the acoustic radiator into melt. Experimental results show that the microstructure with fine uniform non-dendrite grain was achieved with ultrasonic vibration of both systems. By compared with the experiment result, the effect of 15 kHz is better than that of 20 kHz under the same condition.