State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, People's Republic of China.
Ultrason Sonochem. 2013 Jan;20(1):144-54. doi: 10.1016/j.ultsonch.2012.06.011. Epub 2012 Jul 3.
Power ultrasonic vibration (20 kHz, 6 μm) was applied to assist the interaction between a liquid Al-Si alloy and solid Ti-6Al-4V substrate in air. The interaction behaviors, including breakage of the oxide film on the Ti-6Al-4V surface, chemical dissolution of solid Ti-6Al-4V, and interfacial chemical reactions, were investigated. Experimental results showed that numerous 2-20 μm diameter-sized pits formed on the Ti-6Al-4V surface. Propagation of ultrasonic waves in the liquid Al-Si alloy resulted in ultrasonic cavitation. When this cavitation occurred at or near the liquid/solid interface, many complex effects were generated at the small zones during the bubble implosion, including micro-jets, hot spots, and acoustic streaming. The breakage behavior of oxide films on the solid Ti-6Al-4V substrate, excessive chemical dissolution of solid Ti-6Al-4V into liquid Al-Si, abnormal interfacial chemical reactions at the interface, and phase transformation between the intermetallic compounds could be wholly ascribed to these ultrasonic effects. An effective bond between Al-Si and Ti-6Al-4V can be produced by ultrasonic-assisted brazing in air.
将功率超声振动（20 kHz，6 μm）应用于液体 Al-Si 合金与空气中的固体 Ti-6Al-4V 基体之间的相互作用。研究了相互作用行为，包括 Ti-6Al-4V 表面氧化膜的破裂、固体 Ti-6Al-4V 的化学溶解以及界面化学反应。实验结果表明，Ti-6Al-4V 表面形成了许多 2-20 μm 直径的凹坑。在液体 Al-Si 合金中传播的超声波会产生超声空化。当这种空化发生在液体/固体界面或附近时，在气泡内爆过程中小区域会产生许多复杂的效应，包括微射流、热点和声流。固体 Ti-6Al-4V 基底上氧化膜的破裂行为、固体 Ti-6Al-4V 大量化学溶解于液体 Al-Si 中、界面处异常的界面化学反应以及金属间化合物之间的相变都可以完全归因于这些超声效应。通过空气中的超声辅助钎焊可以在 Al-Si 和 Ti-6Al-4V 之间形成有效的连接。
