二元Ti-Al合金高温氧化机理

OXIDATION MECHANISM OF BINARY Ti-Al ALLOYS AT ELEVATED TEMPERATURE

研究了Ti－33．3％Al，Ti－48％Al和Ti－52％Al（原子分数）合金在1073和1173K空气中的恒温氢化行为，用X射线衍射仪（XRD）和配有能谱仪（EDS）的扫描电子显微镜（SEM）对氧化层表面的相组成、形貌以及氧化层剖面的显微结构和氧化机理进行了分析结果表明：二元Ti-Al合金的氧化层由一系列薄层组成，其氢化过程可以分为三个阶段，不同阶段氧化层的生长方向及氧化反应的控制步骤略有差别。

The isothermal oxidation behavior of Ti-33.3% Al, Ti-48% Al and Ti-52%Al(atomic fraction) intermetallic compounds oxidated at 1073 and 1173K in air was investigated. The reaction products of the oxidation scale were examined by XRD, and the surface morphology and cross-section microstructure of the oxidation scale were analyzed by SEM equipped with EDS. The results indicated that the oxidation scale of binary Ti-Al alloys was consisted of a series of thin layers, and the oxidation process could be classified into three steps, the growing direction of the oxidation scale and the rate-controlling factor of various steps is somewhat different; the isothermal oxidation kinetic curves mainly follow parabolic rate law.