论文部分内容阅读
利用交变磁场与温度场耦合作用,通过控制Al-Si合金熔析结晶时硅晶体生长过程中固液界面的稳定性,解决硅熔析精炼过程中硅晶体与合金熔剂分离难的问题,分析了耦合物理场在结晶过程中的作用机理.结果表明,硅铝合金熔体中硅含量越高,越难发生成分过冷现象,固液界面越稳定,有助于生成致密的块状硅晶体;坩埚内径由3 cm降至1 cm,熔体内温度场分布发生变化,固液界面曲率由16.7变为125,形成的硅晶体更致密,硅晶体与合金熔剂的分离效果增强,硅晶体区域所占比例由0.57减小至0.42;下拉速度越慢,固液界面越稳定,硅晶体与合金熔剂的原位分离效果越好,当其为0.05 mm/min时,样品底部硅晶体比例为99.9%,而样品顶部基本没有硅晶体.电磁场的电磁搅拌作用可增大熔体流动,强化熔体传质,增大固液界面前沿硅含量,提高固液界面稳定性.
By using the coupling effect of alternating magnetic field and temperature field, the stability of the solid-liquid interface during the growth of silicon crystal during Al-Si alloy melt-crystallization is controlled, and the problem of difficult separation between Si-Si alloy and alloy flux during the process of Si- The mechanism of coupling physics in the crystallization process was studied.The results show that the higher the silicon content in the melt, the harder the component is to be cooled, and the more stable the solid-liquid interface is, which is conducive to the formation of dense bulk silicon crystals ; The inner diameter of the crucible is reduced from 3 cm to 1 cm, the temperature field distribution in the melt changes, the curvature of the solid-liquid interface changes from 16.7 to 125, the formed silicon crystal is denser, the separation effect between the silicon crystal and the alloy flux is enhanced, The proportion of silicon melt decreases from 0.57 to 0.42. The slower the pull-down speed, the more stable the solid-liquid interface, the better the in-situ separation effect between silicon and alloy flux. When the ratio is 0.05 mm / min, %, While there is almost no silicon crystals on the top of the sample.The electromagnetic stirring effect of electromagnetic field can increase the melt flow, strengthen the melt mass transfer, increase the silicon content at the front of the solid-liquid interface and improve the stability of the solid-liquid interface.