超声波探针水平位置变化对Al-1.0%Cu铸锭凝固组织的影响

本文通过使用Al-1.0%Cu合金进行了一系列试验,研究了超声波探针水平位置变化对铸锭凝固组织的影响,并且使用铝粉-水的混合物进行了模拟试验,观察了探针水平位置变化对透明容器内物质流动的影响,最后,探讨了超声波的晶粒细化机理。结果表明:(1)在探针固定于水平方向不同位置的条件下,当探针位于铸型中心线浸入熔体时,得到的细等轴晶区最大,且呈对称分布。(2)当探针的固定位置贴近铸型壁时,细等轴晶区向探针端面附近集中并缩减,柱状晶区进一步扩大。(3)根据克劳修斯-克拉柏龙方程,细等轴晶是由于超声波引起压力脉冲而导致金属的熔点上升,生成稳定的固相而形成的。(4)强声流起着分散金属熔体内刚形成的固相的作用。

EFFECT OF PROBE HORIZONTAL LOCATION ON CRYSTAL STRUCTURE OF INGOT DURING SOLIDIFICATION OF Al-1.0% Cu ALLOY UNDER ULTRASONIC VIBRATION

A series of experiments are conducted by Al-1.0%Cu alloy to investigate the effect of probe horizontal location on solidification structure of ingots.In addition,using mixture of aluminum powder and water carried out the simulation test.Finally,the mechanism of grain refinement under ultrasonic field is investigated.The results show that:(1) The equiaxed grain zone is the biggest when the probe position is at the centerline of the mould in the conditions of probe set at difference horizontal positions.(2) The equiaxed grain zone is reduced to the probe end when the probe position is nearby the mould wall.(3) The finer equiaxed crystal produced is because that the Clausious-Clapyron Equation indicates that the effect of the pressure waves induced by ultrasonics of this intensity are totally inadequate to cause a phase change of liquid to solid due to the increase of melting point.(4) The acoustic streaming distributes the new solid phase.