(1. 中南大学 冶金与环境学院，长沙 410083；
2. 中南大学 资源循环研究院，长沙 410083)
摘 要: 传统的克劳尔方法制备锆铌合金存在工艺流程长、易被杂质元素污染等问题。本文提出一种利用氢气辅助镁还原-压制烧结直接制备锆铌合金的新工艺。以Zr-2.5Nb为目标合金，在氢气气氛下利用镁粉还原金属氧化物ZrO2和Nb2O5的混合物，成功制备出氧质量分数低至0.038%的Zr-2.5Nb氢化合金粉末，之后对制备出的合金粉末进行冷等静压-烧结，制备Zr-2.5Nb合金。对制备出的合金粉末的元素含量、形貌及粒度进行了分析，探究了烧结温度对合金性能的影响。结果表明：合金粉末中Nb质量分数为2.29%，平均粒度为61.88 μm。当烧结温度为1400 ℃时，合金产品致密度和硬度分别达到最大，分别为95.36%和250.3 HV，合金的压缩强度在1300 ℃时达到最高值1059 MPa。制备出的合金硬度和压缩性能均满足美国工业核级锆合金标准。
关键字: 还原；Zr-Nb合金；粉末；烧结
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Research Institute of Resource Recycling, Central South University, Changsha 410083, China）
Abstract:The traditional Kroll method for preparing zirconium alloy has a long process and is easy to be polluted by impurity elements. In this paper, a new method for directly preparing alloy by sintering Zr-Nb alloy powder via hydrogen assisted magnesium thermal reduction of metal oxide was proposed. Taking Zr-2.5Nb as the target alloy, Zr-2.5Nb hydrogenated alloy powder with 0.038% oxygen content was successfully prepared by reducing the mixture of ZrO2 and Nb2O5 with magnesium powder in hydrogen atmosphere first. After that, Zr-2.5Nb alloy was prepared by cold isostatic and sintering. The results show that the oxygen content in the alloy powder is only 0.038% and the Nb content is 2.29%. At a sintering temperature of 1400 ℃, the maximum densification degree of alloy products is 95.36% and the maximum hardness is 250.3 HV. However, the compressive strength of the alloy decreased from 1059 MPa sintered at 1300 ℃ to 978 MPa sintered at 1400 ℃. The hardness and compressibility of the prepared alloy meet the American Standard of nuclear grade industrial zirconium alloy.
Key words: reduction; Zr-Nb alloy; powder; sintering
