超声波探头位置对Al-5.7%Cu铸锭凝固组织的影响

Effect of Ultrasonic Probe Location on Solidification Structure of Al-5.7%Cu Alloy Ingot

研究了超声波探头位置变化对Al-5.7%Cu合金铸锭凝固组织的影响,考察了探头水平位置变化对等轴晶占有率的影响,探讨了超声波作用下晶粒细化机理。结果表明:当探头浸入深度相同且位于铸型中心线时,得到的细等轴晶区最大,且呈对称分布;当探头的位置贴近铸型壁时,细等轴晶区向探头端面附近集中并缩减,柱状晶区进一步扩大。超声波的细化效果来自于声空化造成微区瞬时过冷,以及动态形核;而声流造成凝固的枝晶破碎,提供结晶核心。

A series of experiments were conducted with Al-5.7%Cu alloy to investigate the effect of probe horizontal location on solidification structure and grain-refining efficiency of ultrasonic ingots.The mechanism of grain refinement in ultrasonic field was discussed.The equiaxed grain zone is the biggest when the probe position was at the centerline of the mould.The equiaxed grain zone is reduced to the probe end when the probe position was nearby the mould wall.Application of ultrasonic vibration resulted in fo...