In this paper we outline the development of a scalable PBF thermal history simulation built on CAPL and based on melt pool physics and dynamics. The new approach inherits linear scalability from CAPL and has three novel ingredients. Firstly, to simulate the laser scanning on a solid surface, we discretize the entire simulation domain instead of only the manufacturing toolpath by appending fictitious paths to the manufacturing toolpath. Secondly, to simulate the scanning on overlapping toolpaths, the path-scale simulations are initialized by a Voronoi diagram for line segments discretized from the manufacturing toolpath. Lastly, we propose a modified conduction model that considers the high thermal gradient around the melt pool. We validate the simulation against melt pool images captured with the co-axial melt pool monitoring (MPM) system on the NIST Additive Manufacturing Metrology Testbed (AMMT). Excellent agreements in the length and width of melt pools are found between simulations and experiments conducted on a custom-controlled laser powder bed fusion (LPBF) testbed on a nickel-alloy (IN625) solid surface. To the authors' best knowledge, this paper is the first to validate a full path-scale thermal history with experimentally acquired melt pool images. Comparing the simulation results and the experimental data, we discuss the influence of laser power on the melt pool length on the path-scale level. We also identify the possible ways to further improve the accuracy of the CAPL simulation without sacrificing efficiency.

翻译：本文概述了一种基于CAPL且依托熔池物理与动力学构建的可扩展粉末床熔融热历史模拟方法。该新方法继承了CAPL的线性可扩展性，并包含三项新颖要素：第一，为模拟实体表面上的激光扫描，我们通过向制造轨迹附加虚拟路径，对整个模拟域进行离散化，而非仅对制造工具路径进行离散；第二，为模拟重叠路径上的扫描，路径尺度模拟通过从制造工具路径离散化得到的线段构建Voronoi图来初始化；第三，我们提出一种考虑熔池周围高热梯度的修正热传导模型。我们利用美国国家标准与技术研究院增材制造计量测试平台上同轴熔池监测系统捕获的熔池图像对模拟结果进行验证。在定制控制的激光粉末床熔融测试平台中，以镍基合金（IN625）实体表面为对象开展的实验与模拟结果在熔池长度和宽度上高度吻合。据作者所知，本文首次利用实验获取的熔池图像完成全路径尺度热历史验证。通过对比模拟结果与实验数据，我们讨论了激光功率对路径尺度熔池长度的影响，并指出了在不牺牲效率的前提下进一步提升CAPL模拟精度的潜在途径。