(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；
2. 遵義鈦業(yè)股份有限責(zé)任公司，遵義 563004；
3. 中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083；
4. 中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 采用原子力顯微鏡(AFM)、掃描電鏡(SEM)和X射線衍射儀(XRD)研究工業(yè)純鈦經(jīng)600、700和800 ℃熱氧化后硬化層的形貌、粗糙度和相結(jié)構(gòu)，分析熱氧化過程中氧原子的擴(kuò)散機(jī)制、滲氧層的形成和氧化膜的分層現(xiàn)象。結(jié)果表明：隨著氧化時(shí)間的延長和溫度的升高，硬化層表面粗糙度增大，氧化物顆粒迅速長大，主要物相為TiO2、Ti2O、Ti3O、Ti6O；鈦的氧化過程是氧原子通過氣相/氧化膜及氧化膜/金屬基體的滲透過程；氧化膜隨著氧化反應(yīng)的加劇和自身的分解，其結(jié)構(gòu)和性質(zhì)發(fā)生變化而導(dǎo)致分層現(xiàn)象。
關(guān)鍵字: 工業(yè)純鈦；氧化膜；高溫氧化；擴(kuò)散機(jī)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
