Research Of Ultrasonic Field On Movement Behavior Of Impurity In Liquid

As the second largest metal material after the steel metal, the quality of aluminium productions is required higher, with the demand of metal products increase rapidly amongst variety of industries. In the industrial production of aluminum alloy, the defects such as gas porosity, oxide inclusion, coarse microstructures and segregation hinder the improvement of industrial production. Currently, ultrasonic field has been applied and studied on the metallurgy and materials processing, it is an opportunity to produce higher quality aluminum alloy.In order to degassing, remove the impurities and refine microstructure, this paper studies the movement behavior of heterogeneous particles and the solidification of aluminium alloy under ultrasonic field. The effect of ultrasonic degassing under different time of A356 Aluminum alloy is studied by using vacuum decompress test, and the effect of ultrasonic field on the solidification microstructure. Research on movement behavior of impurities in aluminum melting under ultrasonic field, by means of polyethylene particles simulation. And based on the results, composition and property graded distribution of Al-Si alloy is fabricated.The following conclusions can be drawn through the test:1. Ultrasonic field is efficient for purification of gas in aluminum melting. The gas content decreases during the ultrasonic action time obviously increasing, and the density has a substantial increases. Degassing results are evident within 120s while the ultrasonic vibrations have little effect on the degassing after 120s.2. Also ultrasonic field is efficient for purification of impurity, clearance decreases with the decrease of particle size, while the clearance can be up to 80% after 60s.3. Using different radiator bars during the experiment, it can be found that graphite sleeve radiator bar will increase the impurity in liquid, while X alloy radiator bar have the similar clearance with stainless steel radiator and have no corrosion, so it can be done further study. After high temperature, the impedance of the radiator bar made of Ta increases 7.2 times, which obstruct the transmission of ultrasonic field. Energy accumulated at the part of the radiator bar made of Ta, which make cracks inside the radiator bar, and the ultrasonic device cannot transfer ultrasonnic field.4. Cavitation and acoustic streaming are the main reasons for ultrasonic degassing, purification of impurity and refinement of solidification microstructure.