冶金硅中杂质相存在形式研究

Morphology of Impurity Phase in Metallurgical Silicon

详细研究了工业硅中杂质存在形式及分布。工业硅中多数杂质偏析在硅晶界,组成深浅不同的杂质相,组分能谱分析证明颜色差异由铁、钛、铝、硅含量不同造成。白色区域是富Fe-Al-Si合金相,其中铁、硅含量分别大于35%和45%;黑色区是富Fe-Ti-Si合金相,钛和铁分别大于20%和30%;其余区域为富Fe-Si合金相,Al、Ti含量较少,Ti含量高颜色深,Al含量多颜色浅,其它金属杂质元素则无规律地分布于杂质相中。杂质分布规律与其含量和分配系数相一致。

Since the existing way of impurity inside metallurgical silicon （MG-Si） was important for MG-Si purifying by metallurgical process, the form and distribution of impurities were carefully studied. Most of the impurities in MG-Si segregated into grain boundary and composed impurity phases with various shades. Results of EDS analysis show that color difference was caused by content difference of Fe, Al, Ti and Si. White area among impurity phases was Fe-A1-Si alloying phase with the contents of Fe and Si more than 35% and 45%, respectively. Black area was Fe- Ti-Si phase with Ti and Fe more than 20% and 30%, respectively. Other areas were Fe-Si phase with less of A1 and Ti. The color of impurity phase darkened with the increase of Ti and lightened with the increase of A1. The other ele- ments distributed disorderly among impurity phases. The distribution rule of most impurity elements was nearly con- sistent with their content and segregation coefficient.