Laser additive manufacturing emerged as an advanced manufacturing process to fabricate components in a layered fashion by fusing the powder particles. This process is multifaceted and pivotal to understand the underlying physics of the coalescence of powder particles during the process, which impacts the structural and mechanical properties of the build component. In this study, a classical molecular dynamics (MD) model is developed for the coalescence of pre-alloyed aluminum alloy (AlSi10Mg) particles during the laser additive manufacturing process. The model is employed to investigate the neck growth and coalescence kinetics of different pairs of particle size with changing the laser energy density from 7 to 17 J/mm². The simulation results reveal that the unevenly sized particles undergo complete coalescence as compared with even-sized particles, and the neck growth rate of AlSi10Mg particles increases with an increase in laser energy density. Based on the present investigation, it is established that the coalescence kinetics of the AlSi10Mg nanoparticles are governed by the surface and volume diffusion and the surface energy reduction during the joining of particles. This analysis will act as a guideline to design process parameters and quality control for the printing of new components.

中文翻译：

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铝合金纳米粒子激光增材制造中聚结动力学和颈部生长的分子动力学模拟。

激光增材制造作为一种先进的制造工艺出现了，该工艺通过融合粉末颗粒以分层方式制造组件。该过程是多方面的且至关重要的，以了解过程中粉末颗粒聚结的基本物理原理，这会影响构建部件的结构和机械性能。在这项研究中，开发了一种经典的分子动力学（MD）模型，用于在激光增材制造过程中预合金铝合金（AlSi10Mg）颗粒的聚结。该模型用于研究不同对粒径的颈部生长和聚结动力学，并将激光能量密度从7 J / mm ²更改为17 J / mm ²。仿真结果表明，不均匀尺寸的颗粒与均匀尺寸的颗粒相比完全融合，并且随着激光能量密度的增加，AlSi10Mg颗粒的颈长率增加。基于目前的研究，确定了AlSi10Mg纳米颗粒的聚结动力学受颗粒连接过程中表面和体积的扩散以及表面能的降低控制。该分析将作为设计过程参数和印刷新组件的质量控制的指南。