在自行设计的微动疲劳试验装置上进行了各向异性镍基合金DD3和DZ125与粉末高温镍基合金FGH95配对接触的微动疲劳试验,对接触区域萌生裂纹的断口形貌进行了观察,分析了轴向和法向应力对微动疲劳寿命以及微动接触区最大等效应力(Von-Mises等效应力)、滑移幅值、法向应变幅值等微动疲劳参数的影响。结果表明:保持法向应力不变,增大轴向应力将会降低DD3和DZ125合金的微动疲劳寿命;保持轴向应力不变,法向应力对微动疲劳寿命的影响不如轴向应力的显著;微动接触区域的最大等效应力和法向应变幅值受法向应力和轴向应力的共同影响,而滑移幅值仅受轴向应力的影响。

A fretting fatigue test apparatus was self-designed and manufactured to carry out the fretting fatigue test for specimens of anisotropic nickel-based alloys DD3 and DZ125 contacted with pad of powder metallurgy superalloy FGH95. The fractures initiating cracks on contact zone were observed, and the effects of axial and normal stress on fretting fatigue life and fretting fatigue parameters, such as maximum equivalent stress(Von-Mises equivalent stress), slip amplitude and normal strain amplitude, were analyzed. The results show that the fretting fatigue life reduce with an increase in axial stress while keeping normal stress at a constant value. Also, the influence of normal stress is not obvious on fretting fatigue life as the effects of axial stress. The maximum equivalent stress and normal strain amplitude are affected by normal stress and axial stress, while the slip amplitude is only affected by axial stress.