A multi-physics CFD study to investigate the impact of laser beam shaping on metal mixing and molten pool dynamics during laser welding of copper to steel for battery terminal-to-casing connections
A multi-physics CFD study to investigate the impact of laser beam shaping on metal mixing and molten pool dynamics during laser welding of copper to steel for battery terminal-to-casing connections
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DOI：
10.1016/j.jmatprotec.2023.118202
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发表时间：
2023-10
影响因子：
6.3
通讯作者：
Giovanni Chianese;Qamar Hayat;S. Jabar;P. Franciosa;Dariusz Ceglarek;S. Patalano
中科院分区：
文献类型：
--
作者：
Giovanni Chianese;Qamar Hayat;S. Jabar;P. Franciosa;Dariusz Ceglarek;S. Patalano
本研究的目的是调查激光束成形的金属混合和熔池动力学的影响，在激光束焊接铜到钢的电池端子到外壳的连接。在300 µm Cu到300 µm镀镍钢的LBW期间测试了四种梁形状。实验和模拟都被用来研究潜在的物理学。首先根据实验校准CFD模型，然后部署以探索增加环到芯直径以及串联激光光斑配置的效果。该研究表明，金属混合受到锁孔动力学和坍塌事件的影响，但锁孔几何形状，通过Marangoni力和浮力的流体动力学之间也存在复杂的相互作用。值得注意的是，由于钢和Cu的不同密度而产生的反作用力，沿着反冲压力，有助于钢朝向Cu的向上流动，并因此有意义地影响材料混合。该研究指出，选择定制的环到芯直径和环到芯功率是在稳定锁孔动力学的需要和减少混合的需要之间进行权衡的决定。研究结果表明，350 µm环和90 µm芯，环功率为30%（焊接配置C3），导致锁孔的动力学更稳定，塌陷事件显著减少，最终控制钢向铜的迁移。此外，使用串列束的预热方法仅导致Cu的局部熔合，并且没有观察到小孔稳定性的显著改善。
This study aims to investigate the impact of laser beam shaping on metal mixing and molten pool dynamics during laser beam welding of Cu-to-steel for battery terminal-to-casing connections. Four beam shapes were tested during LBW of 300 µm Cu to 300 µm nickel-plated steel. Both experiments and simulations were used to study the underlying physics. A CFD model was firstly calibrated against experiments and then deployed to explore the effect of the increasing ring-to-core diameter, as well as a tandem laser spot configuration. The study showed that metal mixing is influenced by the keyhole dynamics and collapse events, but also there is an intricate interplay between keyhole geometry, fluid dynamics via Marangoni forces and buoyancy forces. Notably, the buoyance forces due to the different densities of steel and Cu, along with the recoil pressure contribute to the upward flow of steel towards Cu, and hence impact meaningfully the material mixing. The study pointed-out that the selection of a custom ring-to-core diameter and ring-to-core power is a decision with a trade-off between the need of stabilising the keyhole dynamics and the need to reduce the mixing. Findings indicated that 350 µm ring and 90 µm core with 30% of ring power (weld configuration C3) resulted in more stable dynamics of the keyhole, with significant reduction of collapse events, and ultimately controlled migration of steel towards Cu. Additionally, the pre-heating approach with the tandem beam only led to local fusion of Cu and no significant improvement in keyhole stability was observed.