(1. 哈尔滨工业大学 金属精密热加工国防科技重点实验室， 哈尔滨 150001；
2. 哈尔滨工业大学 现代焊接生产技术国家重点实验室，哈尔滨 150001；
3. 哈尔滨工业大学 材料科学与工程学院，哈尔滨 150001)
摘 要: 采用NH4F溶液对γ-TiAl合金进行表面氟化处理，以提高TiAl合金的抗高温氧化性能。分别研究经过氟化处理和未处理试样在850和900 ℃时的高温氧化行为及NH4F溶液浓度对合金氧化层组织结构的影响。结果表明，经过NH4F溶液处理TiAl合金高温氧化层的组织比未处理合金更加致密，高温氧化抗力高于未处理合金的。850 ℃氧化时，TiAl合金氧化抗力随NH4F溶液浓度的增高而增加；900 ℃氧化时，TiAl合金氧化后的质量增量不随NH4F溶液浓度增加而改变。
关键字: γ-TiAl合金；高温氧化；氟化处理；组织结构
high temperature oxidation behaviors of γ-TiAl alloy
（1. National Key Laboratory for Precision Hot Processing of Metals,
Harbin Institute of Technology, Harbin 150001, China;
2. School of Material Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
3. State Key Laboratory of Advanced Welding and Joining,
Harbin Institute of Technology, Harbin 150001, China）
Abstract:The surface of γ-TiAl alloy was treated by dipping into NH4F solution to improve the high temperature oxidation resistance of this alloy. The high-temperature oxidation behaviors and the effect of solution concentration on the microstructure of oxide layer were investigated at 850 and 900 ℃, respectively. The results show that the high-temperature oxidation layer of the treated alloy is more compact than that of the untreated alloy, and a higher oxidation resistance of the treated alloy is obtained. The oxidation resistance of the treated alloy increases with the increase of NH4F solution concentration at 850 ℃, while the mass gain of the alloy after oxidation is independent of the NH4F solution concentration at 900 ℃.
Key words: γ-TiAl alloy; high-temperature oxidation; fluorinated treatment; microstructure
