Competing crack initiation behaviors of a laser additively manufactured nickel-based superalloy in high and very high cycle fatigue regimes
Competing crack initiation behaviors of a laser additively manufactured nickel-based superalloy in high and very high cycle fatigue regimes
复制标题
激光增材制造的镍基高温合金在高循环和极高循环疲劳状态下的竞争裂纹萌生行为
DOI：
10.1016/j.ijfatigue.2020.105580
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发表时间：
2020-07-01
影响因子：
6
通讯作者：
Chen, Qiang
中科院分区：
文献类型：
--
作者：
Yang, Kun;Huang, Qi;Chen, Qiang
进行超声波疲劳测试是为了研究激光增材制造的 Inconel 718 (IN718) 合金在沉积状态下的高循环和极高循环疲劳行为。结果表明，表面和内部裂纹萌生之间的竞争失效行为导致了单独的 S-N 曲线。由于对制造缺陷的有效限制，制造缺陷（如气孔、未熔合）和显微组织中观察到的柱状晶（基体）都可以作为原始疲劳微裂纹。疲劳敏感性水平随着最大微裂纹的类型、尺寸和位置而逐渐增加。
Ultrasonic fatigue tests were performed to investigate high and very high cycle fatigue behaviors of a laser additively manufactured Inconel 718 (IN718) alloy in the as-deposited condition. The results indicate that the competition failure behavior between the surface and interior crack initiation results in the separate S-N curve. Both manufacturing defects (e.g., gas pore, lack of fusion) and columnar grains (matrix) observed in the microstructure could act as the original fatigue micro-cracks due to the effective restriction on manufacturing defects. The fatigue sensitivity levels increase successively in terms of the type, size, and location of the maximal micro-crack.