本文選題：鎳基單晶高溫合金 + 晶體學取向�。� 參考：《金屬學報》2015年10期

【摘要】：選用第二代鎳基單晶高溫合金,制備了平行于定向凝固方向且分別沿(100)面和(110)面的2組板式試樣,采用電火花方法在試樣中心垂直于板面加工孔徑為0.5 mm的圓孔.采用室溫到1100℃的冷熱疲勞實驗,研究了冷熱循環(huán)過程中不同晶體學平面的板式試樣上圓孔周圍裂紋萌生及擴展行為.結果表明,位于不同晶體學平面的板式試樣中,電火花方法加工圓孔周圍產生了一薄層再鑄層,再鑄層最厚處約15 μm.板式試樣所在晶體學平面對圓孔周圍裂紋萌生及擴展行為影響顯著.冷熱循環(huán)80 cyc后,(110)面試樣中,裂紋在與枝晶生長方向垂直的孔邊產生,之后迅速沿與枝晶生長方向呈45°角擴展.而對于(100)面試樣,即使經過200 cyc冷熱循環(huán)后孔邊也未觀察到裂紋,造成此差異的本質原因是單晶高溫合金晶體結構的各向異性導致的熱應力差別與微觀組織特征共同作用的結果.
[Abstract]:Two groups of plate specimens, parallel to the directional solidification direction and along the plane of 100 and 110), were prepared by using the second generation nickel base single crystal superalloy. The holes with a diameter of 0.5 mm perpendicular to the plate surface were machined by EDM method in the center of the specimen. The initiation and propagation behavior of cracks around circular holes in plate specimens with different crystallographic planes during cold and thermal cycling were studied by means of cold and thermal fatigue tests from room temperature to 1100 鈩，

本文編號：1781015