【摘要】：采用光學顯微鏡、場發(fā)射掃描電子顯微鏡和透射電子顯微鏡,系統研究了低錯配度的第三代高性能粉末高溫合金(FGH98I)在熱處理條件下由合金晶界上γ′相不同析出行為造成的鋸齒晶界。結果表明:在晶界上析出γ′相形態(tài)不同是鋸齒晶界形成的主導因素。熱處理時固溶冷卻速率不同,晶界上析出的γ′相數量、尺寸和形態(tài)不同,對晶界鋸齒形狀有強烈影響。當冷卻速率由0.1℃/s增大至10.8℃/s時,晶界鋸齒振幅由4.02μm變?yōu)?.63μm,鋸齒的波長則隨冷卻速率增大而變大。γ′相形態(tài)失穩(wěn)的不同形狀和尺寸是造成晶界鋸齒振幅大小的主要因素。晶界兩側分布著不同密度的γ′相顆粒,也可使晶界發(fā)生位移形成波浪式小振幅鋸齒晶界。根據實驗結果,提出了有關鋸齒晶界的形成模式。
[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 緯 'phase at grain boundaries. The results show that the different morphology of 緯 'phase at grain boundaries is the dominant factor in the formation of zigzag grain boundaries. The number, size and shape of 緯 '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，

本文編號：2403991