Ta–W alloys have unique properties but their applications at high temperatures are restricted due to their poor oxidation resistances. The addition of Al and Ti decreases the oxidation rate of the alloy, as Al-contained protective oxide layer could be formed. In this study, ternary and quaternary Ta–W alloys containing Al and Ti were prepared by hot press sintering. The microstructures and oxidation behaviors of the alloys were studied at 1173 K. The results show that the oxidation kinetics of all alloys follows a parabolic law at short oxidation periods. After cyclic oxidation, the kinetics of quaternary alloys still obeys the parabolic law but that of ternary alloy has been changed into linear law kinetics after 8-h oxidation. For ternary alloy, an outer layer with dense and continuous alumina was formed during the initial stage, and phase transformation caused the oxides to peel off. By comparison, the quaternary alloys depicted continuously solid solution of the oxides layer. Overall, Al and Ti played key roles in oxidation degree and affected the oxidation kinetics of ternary and quaternary alloys.

中文翻译：

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多组分 Ta-W-Al-Ti 合金在 1173 K 的氧化行为

Ta-W合金具有独特的性能，但由于其抗氧化性差，限制了它们在高温下的应用。Al和Ti的添加降低了合金的氧化速率，因为可以形成含Al的保护性氧化层。在本研究中，通过热压烧结制备了含有 Al 和 Ti 的三元和四元 Ta-W 合金。在1173 K下研究了合金的微观结构和氧化行为。结果表明，所有合金的氧化动力学在短氧化期都遵循抛物线规律。循环氧化后，四元合金的动力学仍服从抛物线规律，但三元合金在氧化8h后已变为线性规律。对于三元合金，在初始阶段形成了致密且连续的氧化铝外层，相变导致氧化物剥离。相比之下，四元合金描绘了氧化物层的连续固溶体。总体而言，Al 和 Ti 在氧化程度中起关键作用，并影响三元和四元合金的氧化动力学。