Cvijović I, Jovanović M T, Vasiljević-Radović D, Perusko D
Institute of Nuclear Sciences 'Vinca', PO Box 522, 11001 Belgrade, Serbia and Montenegro.
J Microsc. 2006 Oct;224(Pt 1):68-71. doi: 10.1111/j.1365-2818.2006.01667.x.
The effect of an 80Ni-20Cr (at.%) metallic coating on the cyclic oxidation behaviour of a Ti(3)Al-based alloy with the composition Ti-25Al-11Nb (at.%) was investigated in this study. Cyclic oxidation tests were carried out in air at 600 degrees C and 900 degrees C for 120 h. For one cycle test, the specimens were held for 24 h at test temperature and then furnace-cooled to room temperature. The oxidation rate was determined by plotting the mass gain per unit surface area of the specimen vs. exposure time. The morphology and composition of the oxidation products were characterized on the cross-section of the specimens by scanning electron microscopy, energy-dispersive X-ray spectroscopy and atomic force microscopy. The oxidation scale forms during exposure at both 600 degrees C and 900 degrees C. TiO(2) is the main oxide component, whereas the Al(2)O(3) layer appears only discontinuously. The remarkable improvement in oxidation resistance at 900 degrees C was attributed to the chemical composition and structure of the scale formed on the 80Ni-20Cr coating.
本研究考察了80Ni-20Cr（原子百分比）金属涂层对Ti-25Al-11Nb（原子百分比）成分的Ti(3)Al基合金循环氧化行为的影响。在600℃和900℃的空气中进行了120小时的循环氧化试验。对于单循环试验，将试样在试验温度下保持24小时，然后炉冷至室温。通过绘制试样单位表面积的质量增益与暴露时间的关系曲线来确定氧化速率。通过扫描电子显微镜、能量色散X射线光谱和原子力显微镜对试样横截面的氧化产物的形态和成分进行了表征。在600℃和900℃暴露期间均形成氧化层。TiO(2)是主要的氧化物成分，而Al(2)O(3)层仅间断出现。900℃时抗氧化性的显著提高归因于80Ni-20Cr涂层上形成的氧化层的化学成分和结构。
