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采用真空非自耗电弧熔炼法制备了5种成分为Nb-22Ti-15Si-5Cr-3Al-3Hf-x Y(x=0,0.03,0.06,0.12,0.30 at%)的合金,并在1250℃下分别进行了1、10、20和50 h的高温氧化实验,研究Y含量对合金电弧熔炼态组织及其高温抗氧化性能的影响。结果表明:添加Y不改变电弧熔炼态合金相组成,组织仍由Nbss及γ-(Nb,X)5Si3相组成,但细化了共晶组织。高温氧化实验结果表明,不同Y含量合金在氧化不同时间后,氧化膜均由Nb2O5,Ti O2,Ti2Nb10O29和Ti Nb2O7组成;随着Y含量的增加,氧化膜中的孔洞和裂纹减少,合金单位面积氧化增重也逐渐减小,表明Y的添加能够显著提高合金的高温抗氧化性能。
Five kinds of alloys with Nb-22Ti-15Si-5Cr-3Al-3Hf-xY (x = 0,0.03,0.06,0.12,0.30at%) were prepared by vacuum non-consumable arc melting method, ℃ for 1, 10, 20 and 50 h respectively. The effect of Y content on the microstructure and high temperature oxidation resistance of the alloy was studied. The results show that the addition of Y does not change the composition of the alloy during the arc melting. The microstructure of the alloy is still composed of Nbss and γ- (Nb, X) 5Si3 phases, but the eutectic structure is refined. The experimental results of high temperature oxidation show that the oxide films consist of Nb2O5, Ti O2, Ti2Nb10O29 and TiNb2O7 after different oxidation times. With the increase of Y content, the pores and cracks in the oxide film decrease, the alloy unit area Oxidation weight gain also gradually reduced, indicating that the addition of Y can significantly improve the high temperature oxidation resistance of the alloy.