Abstract The very high cycle fatigue properties of the Ni-based single-crystal superalloy CMSX-4 coated with an MCrAlY type coating and grit-blasted were studied at 1000 °C, 20 kHz and R = -1. A recrystallized layer thicker than the size of the larger casting pores (>50 μm) drastically reduces the fatigue life without environmental influence. The recrystallized layer and roughness introduced by grit-blasting degrades the environmental resistance of the alloy and the resultant fatigue life. The fatigue life of the coated specimens is also greatly reduced from damage accumulation in the interdiffusion zone by grain boundary cracking, oxidation and internal nitridation.

中文翻译：

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涂层和喷砂处理的镍基单晶高温合金的高周疲劳损伤机制

摘要 在 1000 °C、20 kHz 和 R = -1 条件下，研究了覆有 MCrAlY 型涂层并经过喷砂处理的 Ni 基单晶高温合金 CMSX-4 的超高周疲劳性能。比较大铸件孔隙 (>50 μm) 更厚的再结晶层会在不受环境影响的情况下显着降低疲劳寿命。喷砂引起的再结晶层和粗糙度降低了合金的环境耐受性和由此产生的疲劳寿命。涂层试样的疲劳寿命也因晶界开裂、氧化和内部氮化在相互扩散区​​的损伤积累而大大降低。