(1. 中南大学 材料科学与工程学院，长沙 410083；
2. 遵义钛业股份有限责任公司，遵义 563004；
3. 中南大学 冶金科学与工程学院，长沙 410083；
4. 中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 采用原子力显微镜(AFM)、扫描电镜(SEM)和X射线衍射仪(XRD)研究工业纯钛经600、700和800 ℃热氧化后硬化层的形貌、粗糙度和相结构，分析热氧化过程中氧原子的扩散机制、渗氧层的形成和氧化膜的分层现象。结果表明：随着氧化时间的延长和温度的升高，硬化层表面粗糙度增大，氧化物颗粒迅速长大，主要物相为TiO2、Ti2O、Ti3O、Ti6O；钛的氧化过程是氧原子通过气相/氧化膜及氧化膜/金属基体的渗透过程；氧化膜随着氧化反应的加剧和自身的分解，其结构和性质发生变化而导致分层现象。
关键字: 工业纯钛；氧化膜；高温氧化；扩散机理
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Zunyi Titanium Industry Co. Ltd., Zunyi 563004, China;
3. School of Metallurgy Science and Engineering, Central South University, Changsha 410083, China;
4. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The morphologies, roughness and phase structure of hardened layer of commercial purity titanium (CP-titanium) after thermal oxidation at 600, 700 and 800 ℃ were investigated by AFM, SEM and XRD. The diffusion mechanism, formation of oxygen-diffusion zone and stratification during the thermal oxidation treatment were analyzed. The results show that the roughnesses of hardened layer increase and the oxide particles grow up continually with the increase of oxidation time and temperature, and the main phases are TiO2, Ti2O, Ti3O and Ti6O. The oxidation process of CP-titanium is that oxygen atom passes the gaseous phase/oxidation film and oxidation film/metallic matrix. The structure and property of oxidation film change and lead to stratification due to the acceleration of oxidation reaction and the decomposition of oxidation film.
Key words: commercial purity titanium; oxidation film; high temperature oxidation; diffusion mechanism
