Ni_3Al基高温合金不同温度下变形组织的透射电镜观察

TEM Observation of Deformation Microstructure of Ni_3Al Base Superalloy at Different Temperatures

本文利用透射电镜对Ni_3Al基高温合金的初始状态、室温和870℃下瞬时拉伸和1100℃持久蠕变试样的微观组织及位错组态进行了观察。结果表明:合金在γ/γ′界面上存在大量网络化的错配位错,这些位错在变形时对基体γ′中的位错运动起强烈的阻碍作用;在1100℃持久蠕变过程中合金组织发生显著变化,γ相聚集回溶成高位错密度的胞状组织,对合金仍起强化作用。γ相是合金的强化相。

The microstructure and dislocation configurations of Ni3Al base superalloy specimens of primary condit-tion , short time tension at room temperature and 8 7 0℃ > protracted creep at 110 0℃ were observed by means of TEM. It was showed that there was a mount of mismatching dislocation network at the Y/Y' interface , and these dislocations played a great hindrance role in dislocation movement in deformed Y' matrix. In the process of protracted creep at 1100℃ microstructure of the alloy changed distinctively into circular structure of high dislocation density because of the Y phase coalescence and resolution, it still had a strengthening effect to the alloy. Y phase was the strengthening phase of the alloy.