Insights into the role of W/B alloying on high-temperature oxidation behavior of Ti42Al5Mn alloy
Insights into the role of W/B alloying on high-temperature oxidation behavior of Ti42Al5Mn alloy
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DOI：
10.1016/j.jmst.2023.09.011
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发表时间：
2023-10
期刊：
影响因子：
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通讯作者：
Peng-xiang Zhao;Hui Ma;Xiao-bing Li;Ming Gao;Yingche Ma;Kui Liu
中科院分区：
文献类型：
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作者：
Peng-xiang Zhao;Hui Ma;Xiao-bing Li;Ming Gao;Yingche Ma;Kui Liu
在本研究中，研究了 Ti42Al5Mn、Ti42Al5Mn0.5 W、Ti42Al5Mn0.5W0.1B 和 Ti42Al5Mn0.8 W 在 800 °C 下的氧化行为。由于无法形成致密的Al2O3保护层，Ti42Al5Mn在800℃氧化过程中遭受严重剥落，并且质量增加显着。氧化皮和基体之间的中间层最初由Laves/Z相组成，但随着氧化时间的延长，转变为α2/Z相。高Ti/Al比的中间层有利于在氧化皮中形成较厚的Al2O3+TiO2混合层，该混合层容易引发裂纹并导致氧化物剥落。 W在TiO2中的掺杂有效抑制了其生成，促进了致密Al2O3层的形成，从而使合金的抗氧化性能显着提高。与Ti42Al5Mn合金相比，Ti42Al5Mn0.8 W在循环氧化300 h后没有出现剥落，动力学曲线由线性规律变为抛物线规律。 Ti42Al5Mn0.8 W合金的中间层由单一的Laves相组成，即使在800 ℃氧化1000 h后也没有变化，为合金中稳定的保护性氧化层的生成提供了有利的基础。在 Ti42Al5Mn0.5 W 合金中添加 0.1 at.% B 细化了其显微组织，并进一步将其抗剥落性能提高到接近 Ti42Al5Mn0.8 W 合金的水平。
In this study, the oxidation behavior of Ti42Al5Mn, Ti42Al5Mn0.5 W, Ti42Al5Mn0.5W0.1B, and Ti42Al5Mn0.8 W was investigated at 800 °C. Due to the inability to form a dense protective Al2O3layer, Ti42Al5Mn suffered severe spallation during oxidation at 800 °C and the mass gain was significant. The intermediate layer between the scale and the substrate was first composed of Laves/Z phase but changed to α2/Z phase with prolonged oxidation. The intermediate layer with high Ti/Al ratio favors the formation of a thick Al2O3+ TiO2mixed layer in the oxide scale which is prone to initiate cracks and cause the spalling of oxides. The doping of W in TiO2effectively inhibited its generation and promoted the formation of a dense Al2O3layer, resulting in a significant improvement in the oxidation resistance of the alloy. Compared to Ti42Al5Mn alloy, Ti42Al5Mn0.8 W showed no spallation after 300 h cyclic oxidation and the kinetic curve changed from liner law to parabolic law. The intermediate layer of Ti42Al5Mn0.8 W alloy was composed of a single Laves phase and remained unchanged even after 1000 h oxidation at 800 ℃, offering a favorable basis for the generation of a stable protective oxide layer in the alloy. The addition of 0.1 at.% B to Ti42Al5Mn0.5 W alloy refined its microstructure and further improved its spallation resistance to a level close to that of Ti42Al5Mn0.8 W alloy.