The oxidation behaviour of ternary Co–Al–W alloys with W contents between 7 and 10 at. $$\%$$ was investigated in detail. Continuous thermogravimetry was conducted between 800 and $$900\,^{\circ }{\hbox {C}}$$ to compare the impact of $$\gamma ^{\prime }$$ volume fraction on the overall mass gain during the comparably long transient stages of oxide-scale growth. Resulting cross-sections were assessed using electron microscope-based analysis methods. To understand prevailing oxidation mechanisms, the development and composition of multilayered oxide scales were the main focus of the present study. Elemental distribution of three individual scale sections was investigated with electron probe microanalysis. No striking impact of the W level in the alloy was found. However, the development of diffusion-limiting barrier layers was demonstrated to change with varying W contents. Continuous alumina layers were only observed after 100-h exposure at $$800\,^{\circ }{\hbox {C}}$$ . For samples with 9 at. $$\%$$ W, the grain structure within the outer Co-oxide layer was characterized with electron backscattered diffraction after the maximum duration of exposure. Individual growth kinetics for three distinguished layers within the oxide scales were used to compare elemental transport depending on the W content in the alloy and the exposure temperature.

中文翻译：

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W含量对三元$$\gamma ^{\prime }$$ γ ′ -800~$$900\,^{\circ }{\hbox {C}}$ - 强化钴基模型合金氧化行为的影响$ 900 ∘ C

W 含量在 7 到 10 at 之间的三元 Co-Al-W 合金的氧化行为。$$\%$$ 进行了详细调查。在 800 美元和 900 美元之间进行连续热重分析，^{\circ }{\hbox {C}}$$ 以比较 $$\gamma ^{\prime }$$ 体积分数对整个过程中总质量增加的影响氧化皮生长的相对较长的瞬态阶段。使用基于电子显微镜的分析方法评估所得横截面。为了了解普遍的氧化机制，多层氧化皮的发展和组成是本研究的主要重点。用电子探针微量分析研究了三个单独尺度部分的元素分布。没有发现合金中 W 水平的显着影响。然而，证明扩散限制阻挡层的发展随着 W 含量的变化而变化。仅在 $800\,^{\circ }{\hbox {C}}$$ 暴露 100 小时后才观察到连续的氧化铝层。对于 9 at 的样品。$$\%$$ W，外Co-氧化物层内的晶粒结构在最长暴露时间后用电子背散射衍射表征。氧化层内三个不同层的单独生长动力学用于比较元素传输，这取决于合金中的 W 含量和暴露温度。在最长暴露时间后，外钴氧化物层内的晶粒结构用电子背散射衍射表征。氧化层内三个不同层的单独生长动力学用于比较元素传输，这取决于合金中的 W 含量和暴露温度。在最长暴露时间后，外钴氧化物层内的晶粒结构用电子背散射衍射表征。氧化层内三个不同层的单独生长动力学用于比较元素传输，这取决于合金中的 W 含量和暴露温度。