研究了镍基单晶高温合金DD10在760℃和980℃条件下低周疲劳过程中的拉-压不对称性行为,并对其机制进行了深入探讨。结果表明,在疲劳试验初期,当应变幅较低时,在两种温度条件下拉-压不对称性都不明显,且拉力略大于压力;随着循环周次或应变幅的增加合金的拉-压不对称性逐渐明显,在760℃时拉力明显大于压力,而在980℃时拉力却明显小于压力。循环初期的拉-压不对称性行为与基体应力状态有关,而在大应变幅下和循环应力稳定阶段拉-压不对称性的正负属性和程度与位错在不同温度拉伸和压缩过程中克服γ′粒子的运动方式不同有关。 The tensile-pressure asymmetry behavior of nickel-based single crystal superalloy DD10 during low cycle fatigue at 760 ℃ and 980 ℃ was studied and its mechanism was discussed in depth. The results show that at the initial fatigue test, when the strain amplitude is low, the pull-pressure asymmetry is not obvious under the two temperature conditions, and the pulling force is slightly greater than the pressure. With the increase of the cycle or strain amplitude, Asymmetric pressure becomes more and more obvious, the tensile force is obviously greater than the pressure at 760 ℃, while the tensile force at 980 ℃ is obviously less than the pressure. The asymmetric behavior of tension-pressure at the initial stage of cyclic loading is related to the stress state of the matrix, while the positive and negative properties and extent of the tension-pressure asymmetry at large strain amplitude and cyclic stress are related to the tensile and compression processes at different temperatures Overcoming γ ’particles in different ways of movement.