研究了DD499单晶高温合金<111>取向700和900℃温度条件下光滑和缺口试样的高温旋转弯曲高周疲劳性能。结果表明:<111>取向DD499合金光滑试样的疲劳强度在700℃为355MPa,在900℃时为400MPa,其疲劳强度和缺口敏感性均随温度的升高而增大。<111>取向DD499合金两种温度光滑试样的疲劳断裂均为多源断裂,断裂机制均表现为沿最密排面{111}面的解理断裂特征;而缺口试样在700℃表现为沿缺口向中心扩展断裂,900℃表现为类似于光滑试样的断裂特征。 The high cycle fatigue behavior of smooth and notched samples at <111> orientation of DD499 single crystal superalloy at 700 and 900 ℃ was investigated. The results show that the fatigue strength of the <111> oriented DD499 alloy is 355 MPa at 700 ℃ and 400 MPa at 900 ℃. The fatigue strength and notch sensitivity increase with increasing temperature. The fatigue fracture of the two samples with <111> orientation DD499 are multi-source faults, and the fracture mechanisms are all characterized by cleavage and fracture along the {111} plane of the most dense surface. However, Broken along the gap to the center, 900 ℃ showed similar to the smooth specimen fracture characteristics.