The effect of grain boundaries on high temperature oxidation of new γ′-strengthened Co–Al–W–B superalloys
The effect of grain boundaries on high temperature oxidation of new γ′-strengthened Co–Al–W–B superalloys
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DOI：
10.1016/j.corsci.2013.10.022
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发表时间：
2014-02
影响因子：
8.3
通讯作者：
L. Klein;B. V. Bartenwerffer;M. Killian;P. Schmuki;S. Virtanen
中科院分区：
文献类型：
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作者：
L. Klein;B. V. Bartenwerffer;M. Killian;P. Schmuki;S. Virtanen
对γ‘强化的Co-Al-W-B单晶高温合金在800℃、900℃和1000℃进行了空气中的等温氧化。与相同成分的多晶合金相比，没有晶界导致在800℃和900℃下的氧化性能较差，而在1000℃下的性能有所改善。在较低温度下，晶界扩散占主导地位，并被认为是增强B在内氧化层中积累和促进形成保护性内Al_2O_3层的原因。然而，在1000℃时，单晶高温合金可以观察到良好的抗氧化性能。
Isothermal oxidation in air was carried out on a γ′-strengthened single crystalline Co–Al–W–B superalloy at 800, 900, and 1000 °C. The absence of grain boundaries leads to inferior oxidation properties at 800 and 900 °C, and improved properties at 1000 °C, compared to a polycrystalline alloy of the same composition. At lower temperatures, grain boundary diffusion is dominant and assumed to be the reason for enhanced B-accumulation in the inner oxide layer and enhanced formation of the protective inner Al2O3layer. However, at 1000 °C superior oxidation resistance of the single crystalline superalloy can be observed.