(1. 福州大学 机械工程及自动化学院,福州 350108;
2. 福州大学 材料科学与工程学院,福州350108;
3. 福建工程学院 材料科学与工程系,福州 350108)
摘 要: 采用SEM、EDS和DSC等方法研究稀土氧化物对采用氟盐法制备Al-Ti-C-RE的热力学影响。结果表明:Al与K2TiF6发生铝热放热反应生成TiA13及部分游离态[Ti],在铝热反应的作用下,稀土氧化物Ce2O3与C发生碳热反应,生成大量的CeC2,该相与游离态[Ti]易反应生成TiC和原子态[Ce],反应生成的[Ce]为表面活性元素,吸附在TiA13相上形成Al2Ti20Ce。DSC分析结果表明,添加稀土氧化物Ce2O3可在1 120 ℃左右自发产生碳热反应。因此,在铝热反应的基础上,利用稀土氧化物与石墨粉之间的碳热反应,不仅可以降低制备Al-Ti-C-RE细化剂的反应温度,同时还可提高C与铝熔体的润湿性,促进TiC粒子的生成。
关键字: Al-Ti-C-RE;稀土氧化物Ce2O3;热力学分析
(1. College of Mechanical Engineering and Automation, Fuzhou University, Fuzhou 350108, China;
2. College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, China;
3. Department of Materials Science and Engineering, Fujian University of Technology, Fuzhou 350108, China)
Abstract:The effects of the rare earth oxide on the thermodynamics of Al-Ti-C-RE master alloy prepared by mixing the potassium titanium fluoride and carbon into aluminum melt were studied by means of SEM, EDS and DSC. The results show that the aluminothermy reaction of the Al melt and K2TiF6 occurs to produce the TiA13 and [Ti] atoms. Then, based on the aluminothermy reaction, the rare earth oxide Ce2O3 reacts with carbon to produce the carbothermy reaction and abundant CeC2 phases form, which react with [Ti] atoms easily to produce the TiC particles and [Ce] atoms. The reacted [Ce] atom is a kind of surface active elements, and easily adsorbs on the TiA13 phases to form the new rare earth compounds Al2Ti20Ce. The DSC analysis results show that the rare earth oxide Ce2O3 has spontaneous carbo-thermal reaction at 1 120 ℃, which decreases the reacting temperature to manufacture Al-Ti-C-RE master alloys, improves the wettability between carbon and aluminum melts and promotes the formation of TiC particles.
Key words: Al-Ti-C-RE; rare earth oxide Ce2O3; thermodynamic analysis