摘要
采用置换原子的热力学模型,计算了Ni-Al-Ta/Mo合金的层错能。分析了Ni-Al-Ta/Mo合金中各元素浓度及温度对层错能的影响。结果表明:Ni-Al-Ta/Mo合金的层错能随Al含量的增加而明显降低,其中,随Al浓度提高,合金中原子偏聚自由能(ΔGsγ→ε)降低,可促进γ′有序相的形成是使合金层错能降低的主要原因。随Mo/Ta含量的提高,可引起置换原子自由能(ΔGγb→ε)降低,原子偏聚自由能(ΔGbγ→ε)升高;随温度提高,Ni-Al-Ta/Mo合金中的置换原子自由能(ΔGbγ→ε)增加,表明合金中发生原子置换需要外部供给能量,而引起原子偏聚自由能(ΔGγs→ε)升高,表明高温不利于溶质原子的偏聚。
Using the thermodynamic model of the substituting atoms, the stacking fault energy （SFE） of Ni-Al-Ta/Mo alloys has been calculated, and the influences of the elements and temperatures on SFE of Ni-Al-Ta （Mo） alloys have been analyzed. Results show that the SFE of Ni-Al-Ta/Mo alloys decreases obviously with the increase of Al concentration, thereinto, the fact that the accumulated Gibbs free energy （△Gs^γ→ε） decreases with the increase of the Al concentration promotes the accumulation of the Al atoms to form the γ＇-Ni3Al order phase with LI2 structure, which is a main reason for reducing SFE of Ni-Al-Ta/Mo alloys. The fact that enhances the concentration of the elements Ta/Mo decreases the replacing Gibbs free energy （△Gb^γ→ε） of atoms, and increases the accumulated Gibbs free energy （△Gs^γ→ε） of atoms. With the elevated temperature, the increment of △Gb^γ→ε shows that the atoms replacing occurred in the alloy needs supplying energy by environment, and the increment of △Gs^γ→ε shows that the atomic accumulation is not easily occurred in high temperature.
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2009年第1期11-15,共5页
Journal of Aeronautical Materials
基金
国家自然科学资金(50571070)
辽宁省教育厅基金(2004C004)
