Abstract Effects of build orientation (0°, 45°, 90°) and post heat treatments (hot isostatic pressing 820 °C, 950 °C or annealing 1020 °C) on the fatigue crack growth rates (FCGRs) of Ti-6Al-4V fabricated by laser powder bed fusion were examined. Coarser α′/α lath thicknesses resulted in slower FCGRs and higher fatigue thresholds while texture and build orientation had little influence. Fatigue thresholds were defined by the ability to transfer slip from one α′/α lath to another, with a minor role of roughness induced crack closure. The transition away from microstructure sensitive FCG occurred where the packet/colony size equaled the cyclic plastic zone size.

中文翻译：

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激光粉末床熔融增材制造 Ti-6Al-4V 的疲劳裂纹扩展行为：后热处理和构建取向的作用

摘要 成型取向（0°、45°、90°）和后热处理（热等静压 820°C、950°C 或退火 1020°C）对 Ti-6Al-疲劳裂纹扩展速率（FCGRs）的影响研究了通过激光粉末床熔融制造的 4V。较粗的 α'/α 板条厚度导致较慢的 FCGR 和较高的疲劳阈值，而纹理和构建方向几乎没有影响。疲劳阈值由将滑移从一个 α'/α 板条转移到另一个的能力来定义，粗糙度引起的裂纹闭合的作用很小。远离微观结构敏感 FCG 的转变发生在包/菌落大小等于循环塑性区大小的地方。