(1. 哈爾濱工業(yè)大學(xué) 金屬精密熱加工國防科技重點(diǎn)實(shí)驗(yàn)室， 哈爾濱 150001；
2. 哈爾濱工業(yè)大學(xué) 現(xiàn)代焊接生產(chǎn)技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，哈爾濱 150001；
3. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150001)
摘 要: 采用NH4F溶液對γ-TiAl合金進(jìn)行表面氟化處理，以提高TiAl合金的抗高溫氧化性能。分別研究經(jīng)過氟化處理和未處理試樣在850和900 ℃時(shí)的高溫氧化行為及NH4F溶液濃度對合金氧化層組織結(jié)構(gòu)的影響。結(jié)果表明，經(jīng)過NH4F溶液處理TiAl合金高溫氧化層的組織比未處理合金更加致密，高溫氧化抗力高于未處理合金的。850 ℃氧化時(shí)，TiAl合金氧化抗力隨NH4F溶液濃度的增高而增加；900 ℃氧化時(shí)，TiAl合金氧化后的質(zhì)量增量不隨NH4F溶液濃度增加而改變。
關(guān)鍵字: γ-TiAl合金；高溫氧化；氟化處理；組織結(jié)構(gòu)
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
