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7050铝合金半连续铸造过程中施加一定功率的超声,晶粒细化较为明显。从结晶热力学和动力学两方面,运用理论计算结合试验分析了超声振动在熔体中引起的空化泡共振机理,发现超声的空化效应能显著增大晶核的振动能量,从而显著增大晶核振动频率,引起晶粒的细化。定量研究了空化效应对7050铝合金铸造凝固过程中能量的传递及晶核振动频率的变化。探讨了超声在铝合金熔体中传播时空化泡的频率及其初始平衡半径对晶核振动频率及其形核规律的影响。
7050 aluminum alloy semi-continuous casting process to impose a certain amount of power ultrasound, grain refinement is more obvious. From the aspects of crystallization thermodynamics and kinetics, the mechanism of cavitation bubble resonance caused by ultrasonic vibration in melt is analyzed by theoretical calculation and combination experiment. It is found that the cavitation effect of ultrasonic wave can significantly increase the vibrational energy of nuclei and thus significantly increase Crystal vibration frequency, causing the grain refinement. The effect of cavitation on the energy transfer and the frequency of nucleation vibration during the solidification of 7050 aluminum alloy was quantitatively studied. The frequency of space-time bubble propagating in the aluminum alloy melt and the initial equilibrium radius of ultrasonic vibration on the nucleation frequency and its nucleation are discussed.