Abstract: Considering the impact of crystal orientation of nickel based single-crystal and contact gap， the rate-dependent crystal plasticity constitutive model was employed to calculate the contact stress and fatigue damage under the temperature gradient load and centrifugal load for turbine blade tenon/mortise complex exposure situation. The results show that contact stress of tenon/mortise mutated very obviously when the gap is less than 3.7μm，but contact gap has less influence on the stress of tenon/mortise when gap is more than 5.4μm. Contact stress and fatigue life are sensitive to the first tooth gap and vary greatly. The second tooth gap also has some influence on contact stress，but the impact on the fatigue life is only obvious among the smaller gap value. Crystal orientation also plays a relatively significant role on the fatigue life，showing the anisotropy of fatigue properties obviously.

Key words: Crystal orientation；Contact gap；Tenon /mortise；Fatigue damage

摘要： 采用率相关晶体塑性滑移理论模型，考虑镍基单晶的晶体取向和涡轮盘/片配合间隙的影响，针对涡轮叶片榫头/榫槽的复杂接触状况，研究了温度梯度载荷和离心载荷作用下三种取向的接触应力和低周疲劳损伤。结果表明:当榫头/榫槽的配合间隙小于3.7μm时，榫头/榫槽的接触应力随间隙值突变比较明显；而间隙值大于5.4μm时影响较小。接触应力和低周疲劳寿命对第一齿间隙值比较敏感，随间隙值的波动变化范围较大；第二齿的间隙对接触应力影响也较大，但对疲劳寿命的影响只在较小间隙值下较为明显。晶体取向对榫头/榫槽接触低周疲劳寿命有比较显著的影响，表现出明显的疲劳性能各向异性。

关键词: 晶体取向；配合间隙；榫头/榫槽；疲劳损伤