Abstract The Mechanisms of fatigue failure in Ti-6Al-2Sn-4Zr-6Mo forged discs are investigated: the effects of forging and machining operations on fatigue are decoupled. A four-point bend fatigue testing approach enabled the crack initiation and propagation characteristics to be studied at multiple locations around the disc periphery. Fatigue performance variation (of ~60%) at different positions, and crack initiation and propagation behaviour were linked to the heterogeneous crystallographic texture - developed during upstream forging. Downstream machining processes were found to increase fatigue life, regardless of the cutting speed. However, circumferential fatigue heterogeneity, inherent from the forging stage was still evident even after machining.

中文翻译：

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锻造织构和加工参数对钛合金圆盘部件疲劳性能的影响

摘要 研究了 Ti-6Al-2Sn-4Zr-6Mo 锻造盘疲劳失效的机理：锻造和机加工操作对疲劳的影响是分离的。四点弯曲疲劳测试方法能够在圆盘周边的多个位置研究裂纹萌生和扩展特性。不同位置的疲劳性能变化（约 60%）以及裂纹萌生和扩展行为与非均质晶体结构有关 - 在上游锻造过程中形成。研究发现，无论切削速度如何，下游加工工艺都会增加疲劳寿命。然而，即使在加工后，锻造阶段固有的周向疲劳不均匀性仍然很明显。