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使用元素Hf和Y对Ti-45Al-8Nb合金进行了微合金化,研究了微合金化前后高铌TiAl基合金在900℃静止空气中的断续氧化行为。结果表明,与Ti-45Al-8Nb合金相比,0.5Hf(mol%)微合金化后合金的抗氧化性无明显变化,0.1Y(mol%)微合金化后合金抗氧化性增强,0.5Hf与0.1Y联合微合金化后合金氧化膜与基体粘附性明显增强,但合金氧化增重明显。对氧化膜进行的扫描电镜(SEM)、能谱分析(EDS)及X射线衍射(XRD)分析表明,单独添加Y及Hf、Y联合添加促进了合金中形成以Al2O3为主的连续致密的氧化层,Hf、Y联合微合金化的合金中存在局部内氧化现象降低了该合金的抗氧化性。
Ti-45Al-8Nb alloys were microalloyed using the elements of Hf and Y. The intermittent oxidation behavior of high-niobium-TiAl-based alloys in still air at 900 ℃ before and after microalloying was studied. The results show that compared with Ti-45Al-8Nb alloy, the oxidation resistance of the alloy after 0.5Hf (mol%) microalloying has no significant change, the oxidation resistance of the alloy increases with 0.1Y (mol%) microalloying, With 0.1Y joint microalloyed alloy oxide film and substrate adhesion was significantly enhanced, but the oxidation of the alloy weight gain significantly. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis showed that the addition of Y, Hf and Y alone promoted the formation of continuous and compact oxidation Layer, Hf, Y joint micro-alloying alloy in the local internal oxidation phenomenon reduces the oxidation resistance of the alloy.