Modelling Creep and Creep Crack Growth of LPBF alloy 718

激光粉床制造(LPBF)制造的组件在关键应用中的性能受到根本限制。对于通过LPBF制备的高温材料，微观结构缺陷(如不利的沉淀形成、次优的晶粒度和分布)和宏观异常(如未融合、层内/层间缺陷)往往导致LPBF组件的性能远远低于其锻造对应件。在本工作中，使用四激光雷尼绍机器制造的718合金零件在650℃的蠕变试验中进行了600兆帕载荷下的蠕变试验。对于给定的策略，观察到与变形合金718相比，蠕变寿命增加了24%。蠕变取向也是蠕变失效机制中的一个决定性因素。蠕变和蠕变裂纹扩展的建模工作正在进行中。因此，作为这项工作的结果，有可能为高温蠕变应用提出构建策略，并能够准确地预测LPBF合金的蠕变性能。

Components manufactured by laser powder bed fabrication (LPBF) are fundamentally limited by their performance for use in critical applications. With respect to high temperature materials produced via LPBF, microstructural defects - such as unfavourable precipitate formation, suboptimal grain size and distribution - and macroscale anomalies - like lack of fusion, intra/inter layer defects - often result in LPBF components performing well below their wrought counterparts.In this work, alloy 718 parts, fabricated using a quad-laser Renishaw machine with different scanning strategies, build orientations and number of lasers, were creep tested at 650 under a 600 MPa load. For a given strategy, a 24% increase in creep life compared to wrought alloy 718 was observed. The build 0rientation was also shown to be a determining factor in the creep failure mechanism.Modelling of creep and Creep crack growth work is underway. It is therefore possible, as a result of this work, to propose build strategies for high temperature creep applications and be able to accurately predict LPBF alloys creeep performance.