(西北有色金屬研究院， 西安 710016)
摘 要: 用SEM及EDS研究了5種TiAl基合金經(jīng)800～1 000 ℃，100 ｈ斷續(xù)氧化及循環(huán)氧化后氧化剖面的結(jié)構(gòu)、組成。結(jié)果顯示，TiAl氧化表面存在分層現(xiàn)象。首先形成（TiO2+Al2O3）混合層，其次是新相過(guò)渡層；較少觀察到連續(xù)的Al2O3層。因應(yīng)力作用，氧化層開(kāi)裂乃至剝離后，化學(xué)分層轉(zhuǎn)入物理分層階段，氧化層保護(hù)性惡化。
關(guān)鍵字: TiAl; 氧化; 分層; 生長(zhǎng)應(yīng)力; 熱應(yīng)力
（Northwest Institute for Nonferrous Metal Research, Xi′an 710016, P.R.China）
Abstract:Interrupted or cyclic oxidation of five TiAlbased alloys at 800～1 000 ℃,100 h were carried out, crosssection microstructure and oxides constitution were investigated by SEM, EDS equipments. The results show that stratification is one of the characteristics of oxidation of TiAl. Mixture layer of TiO2+Al2O3 is formed firstly, after that there is the formation of diffusion zone inside and pure TiO2 scale outside. Continuous Al2O3 film is observed scarcel. Chemical stratification is transformed into physical stratification once delamination occurs due to the effect of growth stress and thermal stress, and the protection of oxide layers is destroyed consequently.
Key words: TiAl; oxidation; stratification; growth stress; thermal stress
