Enhancing B removal from Si with small amounts of Ti in electromagnetic solidification refining with Al-Si alloy
Enhancing B removal from Si with small amounts of Ti in electromagnetic solidification refining with Al-Si alloy
复制标题
铝硅合金电磁凝固精炼中添加少量Ti促进Si中B的去除
DOI：
10.1016/j.jallcom.2016.01.127
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发表时间：
2016
影响因子：
6.2
通讯作者：
Morita Kazuki
中科院分区：
文献类型：
--
作者：
Lei Yun;Sun Luen;Ma Wenhui;Wei Kuixian;Morita Kazuki
采用少量Ti（<2037 ppma）作为添加剂，以增强用Al-Si合金进行电磁凝固精炼时从Si中去除B。通过改变Ti的初始浓度、冷却速率和Al-Si合金的液相线温度，研究了B的去除过程。实验结果表明，少量的Ti是主要负责增强B去除。该B去除过程在较低的冷却速率下结合使用具有较低液相线温度的Al-Si合金溶剂更有效。加入2037 ppma的Ti，可将精炼硅中残留的B控制在1.2 ppma，满足太阳能电池的制造要求。由于Ti在固态Si和液态Al-Si合金之间的偏析系数极低，可同时去除。尽管在精炼的Si中存在痕量的Ti和Al，但预期它们在下一个加工步骤（真空中的定向凝固）中被去除。最后，对该脱B过程的机理进行了讨论。
Small amounts of Ti (<2037 ppma) were employed as an additive to enhance B removal from Si in electromagnetic solidification refining with an Al–Si alloy. The B removal process was investigated by varying the initial concentration of Ti, the cooling rate, and the liquidus temperature of the Al–Si alloy. Experimental results show that the small amounts of Ti were primarily responsible for enhancing B removal. This B removal process was more efficient at lower cooling rates combined with the use of Al–Si alloy solvents having lower liquidus temperatures. With the addition of 2037 ppma Ti, the residual B in the refined Si could be controlled to 1.2 ppma, which meets the requirements for manufacturing solar cells. The added Ti could be simultaneously removed because of its extremely low segregation coefficient between solid Si and liquid Al–Si alloy. Although trace amounts of Ti and Al were present in the refined Si, they are expected to be removed in the next processing step, which is directional solidification in vacuum. Finally, the mechanism of this B removal process is discussed.