高性能镍基粉末高温合金中γ′相形态致锯齿晶界形成机理研究
发布时间：2019-01-07 18:33
【摘要】：采用光学显微镜、场发射扫描电子显微镜和透射电子显微镜,系统研究了低错配度的第三代高性能粉末高温合金(FGH98I)在热处理条件下由合金晶界上γ′相不同析出行为造成的锯齿晶界。结果表明:在晶界上析出γ′相形态不同是锯齿晶界形成的主导因素。热处理时固溶冷却速率不同,晶界上析出的γ′相数量、尺寸和形态不同,对晶界锯齿形状有强烈影响。当冷却速率由0.1℃/s增大至10.8℃/s时,晶界锯齿振幅由4.02μm变为0.63μm,锯齿的波长则随冷却速率增大而变大。γ′相形态失稳的不同形状和尺寸是造成晶界锯齿振幅大小的主要因素。晶界两侧分布着不同密度的γ′相颗粒,也可使晶界发生位移形成波浪式小振幅锯齿晶界。根据实验结果,提出了有关锯齿晶界的形成模式。
[Abstract]:Using optical microscope, field emission scanning electron microscope and transmission electron microscope, The sawtooth grain boundaries of the third generation high performance powder superalloys (FGH98I) with low mismatch under heat treatment were investigated by different precipitation behavior of 纬 'phase at grain boundaries. The results show that the different morphology of 纬 'phase at grain boundaries is the dominant factor in the formation of zigzag grain boundaries. The number, size and shape of 纬 'phase precipitated on grain boundary are different with different cooling rate of solid solution during heat treatment, which have a strong influence on the shape of sawtooth of grain boundary. When the cooling rate was increased from 0.1 鈩，
本文编号：2403991
[Abstract]:Using optical microscope, field emission scanning electron microscope and transmission electron microscope, The sawtooth grain boundaries of the third generation high performance powder superalloys (FGH98I) with low mismatch under heat treatment were investigated by different precipitation behavior of 纬 'phase at grain boundaries. The results show that the different morphology of 纬 'phase at grain boundaries is the dominant factor in the formation of zigzag grain boundaries. The number, size and shape of 纬 'phase precipitated on grain boundary are different with different cooling rate of solid solution during heat treatment, which have a strong influence on the shape of sawtooth of grain boundary. When the cooling rate was increased from 0.1 鈩，
本文编号：2403991
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