Following foreign object damage (FOD), a decision to repair components using novel additive manufacturing (AM) technologies has good potential to enable cost-effective and efficient solutions for aircraft gas turbine engine maintenance. To implement any new technology in the gas turbine remanufacturing world, the performance of the repair must be developed and understood through careful consideration of the impact of service life-limiting factors on the structural integrity of the component. In modern gas turbine engines, high cycle fatigue (HCF) is one of the greatest causes of component failure. However, conventional uniaxial fatigue data is inadequate in representing the predominant HCF failure mode of gas turbine components that is caused by vibration. In this study, the vibratory fatigue behavior of Ti6Al4V deposited using wire-fed electron beam additive manufacturing (EBAM) was examined with the motivation of developing an advanced repair solution for fatigue critical cold-section parts, such as blades and vanes, in gas turbine engine applications. High cycle fatigue data, generated using a combination of step-testing procedure and vibration (resonance) fatigue testing, was analyzed through Dixon–Mood statistics to calculate the endurance limits and standard deviations of the EBAM and wrought Ti6Al4V materials. Also plots of stress (S) against the number of cycles to failure (N) were obtained for both materials. The average fatigue endurance limit of the EBAM Ti6Al4V was determined to be greater than the wrought counterpart. But the lower limit (95% reliability) of 426 MPa for the EBAM Ti6Al4V was lower than the value of 497 MPa determined for wrought Ti6Al4V and was attributed to the slightly higher data scatter–as reflected by the higher standard deviation–of the former material.

中文翻译：

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送丝电子束增材制造技术制备的Ti6Al4V的高频振动疲劳行为

在异物损坏（FOD）之后，决定使用新颖的增材制造（AM）技术修复组件的潜力很大，从而有可能为飞机燃气涡轮发动机的维护提供经济高效的解决方案。为了在燃气轮机再制造领域实施任何新技术，必须通过仔细考虑使用寿命限制因素对部件结构完整性的影响来开发和理解维修性能。在现代燃气涡轮发动机中，高循环疲劳（HCF）是造成组件故障的最大原因之一。然而，常规的单轴疲劳数据不足以表示由振动引起的燃气轮机部件的主要HCF故障模式。在这个研究中，为了研究为燃气轮机应用中的疲劳关键冷段零件（例如叶片和叶片）开发先进的修复解决方案，研究了使用线馈电子束增材制造（EBAM）沉积的Ti6Al4V的振动疲劳行为。通过阶跃测试程序和振动（共振）疲劳测试相结合生成的高周疲劳数据，通过Dixon-Mood统计数据进行了分析，以计算EBAM和锻制Ti6Al4V材料的耐久性极限和标准偏差。还获得了两种材料的应力（S）与失效循环数（N）的关系图。EBAM Ti6Al4V的平均疲劳极限被确定为大于锻造的对应极限。