Sales Andrew, Khanna Aditya, Hughes James, Yin Ling, Kotousov Andrei
School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia.
AML3D Limited, 35 Woomera Avenue, Edinburgh, SA 5111, Australia.
Materials (Basel). 2024 Apr 17;17(8):1842. doi: 10.3390/ma17081842.
Additive manufacturing offers greater flexibility in the design and fabrication of structural components with complex shapes. However, the use of additively manufactured parts for load-bearing structural applications, specifically involving cyclic loading, requires a thorough investigation of material fatigue properties. These properties can be affected by many factors, including residual stresses and crack tip shielding mechanisms, which can be very different from those of conventionally manufactured materials. This research focuses on super duplex stainless steels (SDSSs) fabricated with wire arc additive manufacturing (WAAM) and investigates their fatigue crack growth rates and the net effect of crack tip shielding mechanisms. Using the compliance-based method, we measured crack tip opening loads in compact tension (CT) specimens with cracks propagating longitudinally and transversely to the WAAM deposition direction. It was found that fatigue crack growth rates were very similar in both directions when correlated by the effective stress intensity factor range. However, the differences in crack tip opening loads explain a quite significant influence of the deposition direction on the fatigue life.
增材制造在设计和制造具有复杂形状的结构部件方面具有更大的灵活性。然而，将增材制造的零件用于承受载荷的结构应用，特别是涉及循环载荷的应用时，需要对材料的疲劳性能进行全面研究。这些性能会受到许多因素的影响，包括残余应力和裂纹尖端屏蔽机制，而这些因素与传统制造材料的情况可能有很大不同。本研究聚焦于采用电弧增材制造（WAAM）工艺制造的超级双相不锈钢（SDSS），并研究其疲劳裂纹扩展速率以及裂纹尖端屏蔽机制的净效应。使用基于柔度的方法，我们测量了紧凑拉伸（CT）试样中裂纹沿纵向和横向于WAAM沉积方向扩展时的裂纹尖端张开载荷。结果发现，当通过有效应力强度因子范围进行关联时，两个方向上的疲劳裂纹扩展速率非常相似。然而，裂纹尖端张开载荷的差异解释了沉积方向对疲劳寿命有相当显著的影响。
