Laser Powder Bed Fusion (LPBF) enables complex structures to be manufactured, which is attractive to industries where augmented service performance can be achieved. However, the build time of LPBF can be slower than traditional manufacturing processes, especially for higher volumes of parts. Multi-laser machines have the potential to significantly reduce process time, but there is little understanding of how interlaced scan strategies impact upon mechanical properties. The results of this work show that multi-laser scan strategies have no adverse effects on the creep properties of LPBF alloy 718 at different build orientations, demonstrating the potential of using multi-laser strategies for faster build rates without compromising the mechanical properties. Indeed, it is shown that for samples built vertically (i.e. where the build direction is parallel to the loading direction), multi-laser samples outperformed their single-laser counterparts and had a similar creep life and secondary creep rate to wrought alloy (1% difference). The single and multi-laser samples built horizontally (i.e. with the build direction perpendicular to the loading direction) and at 45° from the loading direction performed similarly and all failed soon after the onset of tertiary creep. It was also found that the failure of components could not be attributed to the interlacing scan strategies used with multi-laser processing, but rather to the build orientation and its effect on the grain orientation with respect to the loading direction and the stress state of the sample. However, the scan strategy, number of lasers, fraction area of solidified layer, powder underneath the layer and the interlayer rotation meant that the layers themselves as well as the samples were heterogenous. Despite this, the creep life for any given sample was within 73 h (i.e.17%) of its repeats, giving confidence in the results. It is therefore possible, as a result of this work, to understand the effects of multi-laser scan strategies, particularly the laser-to-laser interfaces on LPBF microstructure. Multi-laser scan strategies are shown to have no detrimental effects on the creep performance, while cutting the build time by more than half.

激光粉末床融合（LPBF）可以制造复杂的结构，这对于可以提高服务性能的行业具有吸引力。但是，LPBF的制造时间可能比传统制造工艺慢，尤其是对于大量零件而言。多激光机具有显着减少处理时间的潜力，但对于隔行扫描策略如何影响机械性能知之甚少。这项工作的结果表明，多激光扫描策略在不同的构建方向上对LPBF合金718的蠕变性能没有不利影响，这表明了使用多激光策略以更快的构建速率而不损害机械性能的潜力。实际上，它表明对于垂直构建的样本（即 （制造方向平行于加载方向），多激光样品的性能优于单激光样品，并且蠕变寿命和二次蠕变速率与锻造合金相似（相差1％）。水平（即，构建方向垂直于加载方向）并与加载方向成45°方向构建的单激光和多激光样品执行类似的操作，并且在三次蠕变发生后不久都失败了。还发现，组件的故障不能归因于多激光加工所使用的隔行扫描策略，而是归因于构造方向及其相对于加载方向和应力状态对晶粒方向的影响。样本。但是，扫描策略，激光器数量，凝固层的分数面积，层下面的粉末和层间旋转意味着层本身以及样品都是异质的。尽管如此，任何给定样品的蠕变寿命都在其重复试验的73小时（即17％）之内，从而使结果充满信心。因此，作为这项工作的结果，有可能了解多激光扫描策略的影响，尤其是激光到激光的界面对LPBF微结构的影响。事实证明，多激光扫描策略对蠕变性能没有不利影响，同时将构建时间减少了一半以上。了解多激光扫描策略的影响，尤其是激光到激光界面对LPBF微结构的影响。事实证明，多激光扫描策略对蠕变性能没有不利影响，同时将构建时间减少了一半以上。了解多激光扫描策略的影响，尤其是激光到激光界面对LPBF微结构的影响。事实证明，多激光扫描策略对蠕变性能没有不利影响，同时将构建时间减少了一半以上。