铌基合金包埋渗法制备抗氧化硅化物涂层及其组织-中国有色金属学报.PDF

第 17 卷第 4 期 中国有色金属学报 2007 年 4 月 Vol.17 No.4 The Chinese Journal of Nonferrous Metals Apr. 2007 文章编号：1004-0609(2007)04-0596-06 铌基合金包埋渗法制备抗氧化硅化物涂层及其组织形成 赵陆翔，郭喜平，姜嫄嫄 (西北工业大学 凝固技术国家重点实验室，西安 710072) 摘 要：利用包埋渗法在铌基合金上制备抗氧化硅化物涂层，渗硅温度分别为 1 050、1 150 和 1 250 ℃，渗硅时 间分别为 2 、5、10、15 和 20 h 。利用 SEM、EDS 和 XRD 等检测手段分析涂层的结构、元素分布及相组成等， 并对涂层形成的反应机理及反应动力学进行讨论。结果表明：涂层的相组成为(Nb, X)Si (X 表示 Ti, Cr, Hf 和 Al 2 等元素) ；涂层具有双层结构，且上层较为致密；涂层与基体之间达到了冶金结合，通过扩散形成过渡层及互扩散 区；在包埋渗温度分别为 1 050、1 150 和 1 250 ℃时，涂层生长的动力学曲线均符合抛物线规律。 关键词：铌基合金；包埋渗；涂层；过渡层；互扩散区；反应动力学 中图分类号：TG 146.4 文献标识码：A Preparation and structural formation of oxidation-resistant silicide coatings on Nb-based alloy by pack cementation technique ZHAO Lu-xiang, GUO Xi-ping, JIANG Yuan-yuan (State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China) Abstract: Oxidation-resistant silicide coatings on an Nb-based alloy were prepared by pack cementation technique. The holding temperatures were 1 050, 1 150 and 1 250 ℃ and the holding time were 2, 5, 10, 15 and 20 h, respectively. The structure, phase constituents and compositional distribution in the coatings were analyzed by SEM, EDS and XRD techniques. The formation mechanism and growth kinetics of the coatings were discussed and measured. The results show that the phase constituent of the coatings is (Nb, X)Si2 (X represents Ti, Cr, Hf and Al elements). Double layers exist in the coatings, and the upper layer is denser. A transitional layer and a diffusion zone f