用感量为2μg的Setaram热天平研究了Ni3Al及Ni3Al-Cr基合金700℃~1100℃的初期氧化行为。Ni3Al合金在中温区(7000℃~900℃)的氧化,随温度升高初期氧化速率明显增加(氧化5min),800℃及900℃氧化0.5h后试样的氧化增重低于700℃的。在温度低于900℃时,Ni3Al-Cr基合金的氧化增重明显小于Ni3Al基合金;高于1000℃时,其氧化增重明显大于Ni3Al基合金的。EDS分析表明Ni3Al-Cr基合金表面不出现纯NiO相的氧化物区。加Cr可降低Ni3Al的晶格常数,增加原子密堆度,从而阻碍Ni原子的扩散,降低合金的氧化速率。
The initial oxidation behavior of Ni3Al and Ni3Al-Cr alloys at a temperature range of 700-1100℃ was investigated using Setaram thermal anaysis instrument with sensitivity of 2 ug. At 700-900℃, the oxidation of Ni3Al in the first 5 minutes was accelerated markedly with increasing temperature. The weight gains of Ni3Al after xoidation for 0.5h at 800℃ and 900℃ was lower than that at 700℃. Addition of chromium into Ni3Al significantly reduced the oxidation rate of the alloy below 900℃, but increased its oxidation rate above 1000℃. The oxide scale was examined by EDS. The results indicated that no plain NiO phase region was observed on the oxide scale of Ni3Al-Cr alloy. Cr addition might decrease the lattice parameters of Ni3Al, increase the packing density and reject the surface diffusion of Ni.
参考文献
[1] | |
[2] | |
[3] | |
[4] | |
[5] | LiuCT,WhiteCL.ActaMetall.,1987,35:6432LiuCT.HighTemperatureOrderedIntermetatlicAlloysII,MRS,Pitlsburgh,PA88 |
- 下载量()
- 访问量()
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%