Reaction of boron to transition metal impurities and its effect on conductivity of aluminum

来源期刊：中国有色金属学报(英文版)2002年第6期

论文作者：王桂芹 刘顺华 李长茂 高钦

文章页码：1112 - 1116

Key words：boron; electrical conductivity; commercial aluminum

Abstract: The effects of boron on electrical conductivity of aluminum and the action mechanism have been investigated. The results indicate that, by combining with the trace amounts of transition elements Ti, V and Zr to form two kinds of insoluble borides, boron can significantly improve the electrical conductivity of commercial aluminum. One of the borides contains 54.42% B, 13.70% Al and 23.39%(mole fraction) transition elements (including Ti, V, Zr and Fe) and is in the form of fine particles. The other one, in hexagonal shape, contains 78.59% B, 14.97% Al and 2.56%(mole fraction) transition elements (including Ti, V and Fe). Neither Cr nor Mn is found in these borides. The conversion of some transition metal impurities from solid solution state to the boride precipitates form leads to a decrease in electrical resistivity, and this decrease constitutes 86.2% of that can be achieved by complete removal of transition element impurities from aluminum melts.