本文選題：鎳基單晶高溫合金 + 晶體學(xué)取向��； 參考：《金屬學(xué)報(bào)》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(shí)驗(yàn),研究了冷熱循環(huán)過(guò)程中不同晶體學(xué)平面的板式試樣上圓孔周?chē)鸭y萌生及擴(kuò)展行為.結(jié)果表明,位于不同晶體學(xué)平面的板式試樣中,電火花方法加工圓孔周?chē)a(chǎn)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(xué)平面對(duì)圓孔周?chē)鸭y萌生及擴(kuò)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(zhǎng)方向垂直的孔邊產(chǎn)生,之后迅速沿與枝晶生長(zhǎng)方向呈45°角擴(kuò)展.而對(duì)于(100)面試樣,即使經(jīng)過(guò)200 cyc冷熱循環(huán)后孔邊也未觀(guān)察到裂紋,造成此差異的本質(zhì)原因是單晶高溫合金晶體結(jié)構(gòu)的各向異性導(dǎo)致的熱應(yīng)力差別與微觀(guān)組織特征共同作用的結(jié)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(hào)：1781015