Al对Cu-20Ni-19Fe合金微观组织和 高温抗氧化性能的影响

刘英 梁志敏 王立伟 彭珍珍 汪殿龙

摘 要：為了解决Cu-Ni-Fe惰性阳极在铝电解过程中高温抗氧化性能差的问题，采用真空熔炼法制备不同Al含量的Cu-20Ni-19Fe-xAl（x=0%，6%，8%，10%，质量分数，下同）合金，于850 ℃和1.013×105 Pa氧分压下进行高温氧化实验，氧化时间为100 h，研究Al添加量对合金微观组织结构及高温氧化性能的影响。结果表明：铸造Cu-20Ni-19Fe合金由富Ni/Fe的枝晶相（γ1）和富Cu，Ni的基体相（γ2）组成;添加6% Al的Cu-20Ni-19Fe合金，Al固溶在合金基体中;添加8%和10%Al的Cu-20Ni-19Fe合金，微观组织中形成了针状或块状NiAl相，且NiAl相随Al含量的增加而增多;Cu-20Ni-19Fe合金在850 ℃和1.013×105 Pa氧分压下氧化动力学呈直线规律;添加Al元素后，合金的高温氧化动力学曲线由直线转变为指数规律，Al含量越高，合金氧化速率指数越小。Al元素的加入提高了Cu-20Ni-19Fe合金的高温抗氧化性能，使其有望成为惰性阳极铝电解中的备选阳极材料。

关键词：有色金属及其合金;Cu-Ni-Fe合金;微观组织;高温氧化;铝电解

中图分类号：TG171 文献标识码：A

doi：10.7535/hbkd.2021yx03012

Effect of Al on the microstructure and high temperature oxidation performance of Cu-20Ni-19Fe alloy

LIU Ying1，2， LIANG Zhimin1，2， WANG Liwei1，2， PENG Zhenzhen1，2， WANG Dianlong1，2

（1.School of Materials Science and Engineering，Hebei University of Science and Technology，Shijiazhuang，Hebei 050018，China;

2.Hebei Key Laboratory of Material Near-net Forming Technology，Shijiazhuang，Hebei 050018，China）

Abstract：In order to solve the problem of poor oxidation resistance of Cu-Ni-Fe inert anode at high temperature during aluminum electrolysis，Cu-20Ni-19Fe-xAl alloys （x=0%，6%，8%，10%） with different Al contents were prepared by vacuum melting method，and the alloys were used for the high temperature oxidation experiments which were carried out at 850 ℃ with oxygen partial pressure of 1.013×105 Pa and oxidation time of 100 h，and the effects of Al addition on the microstructure and high temperature oxidation properties of the alloy were investigated.The results show that the as-cast Cu-20Ni-19Fe alloy is composed of Ni/Fe-rich dendritic phase （γ1） and Cu/Ni-rich matrix phase （γ2）;Al was dissolved in the Cu-20Ni-19Fe alloy matrix with 6% content of Al added;The needle-like or blocky NiAl phase was formed in the microstructure of Cu-20Ni-19Fe alloy with 8% and 10% Al added;The content of NiAl phase increases with the increasing addition of Al;The oxidation kinetics of Cu-20Ni-19Fe alloy follow the straight line under 850 ℃ and oxygen partial pressure of 1.013×105 Pa;After the addition of Al，the oxidation kinetic curve of Cu-20Ni-19Fe-xAl alloy follow an exponential law，and the oxidation rate index of the Cu-20Ni-19Fe-xAl alloy was much smaller with more content of Al.The high-temperature oxidation resistance of Cu-20Ni-19Fe alloy was greatly improved by the addition of Al，which proves the Cu-20Ni-19Fe alloy may be used as an alternative anode material for aluminum electrolysis.

Keywords：

nonferrous metals and their alloys;Cu-Ni-Fe alloy;microstructure;high temperature oxidation;aluminium electrolysis

Cu-Ni合金由于具有优良的力学性能和耐腐蚀性而得到了广泛应用[1-2]。在Cu-Ni合金中加入Fe元素，可以提高合金的高温力学性能;加入Al元素，可以形成NiAl相，提高合金的强度和耐腐蚀性能[3]，用作新型无碳铝冶炼中的阳极材料[4-7]。然而，在无碳铝冶炼用阳极材料的工程应用中，电解析氧高温熔盐环境会使Cu-Ni合金因铜的快速扩散氧化而表现出较差的抗氧化性能。电解原铝中Cu杂质含量过高[8-9]，会限制Cu-Ni基阳极材料的工程化应用。

在合金中添加活性元素，是一种常见的提高合金力学性能和抗氧化性能的方法。……