Abstract As a combination of the annular laser beam and gaussian laser beam, adjustable ring mode (ARM) laser is a promising technology for stabilizing laser-based welding process. Process status and fusion efficiency of laser-materials processing was investigated experimentally under different shape of laser modes, including ring laser mode, center laser spot alone, and ring/center dual spots, with welding speeds ranging from 5 to 100 mm/s. The process characteristics of the keyhole entrance, including the area, length, and width were monitored and quantified by a high-speed CCD camera with the selected image processing method. The process intensity of metallic vapor and plasma was further monitored by a spectrometer, and the relationship between plasma intensity and the keyhole entrance geometry was analyzed correspondingly. Additionally, individual effects of shaped laser beam on the geometric characteristics of the fusion zone across the weld cross-sections such as effective depth of penetration, and the area and width of the fusion zone were analyzed accordingly. Experimental results showed that the process variation of the keyhole entrance differ with different welding energy modes, and the main difference came from the variation of keyhole length. The plasma intensity had a positive relationship with the keyhole entrance in different shape of laser beam welding. The fusion efficiency of cross-section was quite different with different laser beams. This work provided a new investigation for researchers and engineers to have a better understanding of shaped laser beam on materials welding.

中文翻译：

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不锈钢的可调环形模式 (ARM) 激光焊接

摘要 作为环形激光束和高斯激光束的组合，可调环模（ARM）激光器是稳定激光焊接过程的一种很有前途的技术。实验研究了激光材料加工在不同形状的激光模式下的工艺状态和融合效率，包括环形激光模式、中心激光光斑和环形/中心双光斑，焊接速度范围为 5 至 100 mm/s。锁孔入口的工艺特性，包括面积、长度和宽度，由高速 CCD 相机和选定的图像处理方法进行监测和量化。通过光谱仪进一步监测金属蒸气和等离子体的工艺强度，并相应地分析等离子体强度与小孔入口几何形状之间的关系。此外，相应地分析了成形激光束对整个焊缝横截面熔合区几何特征的影响，例如有效熔深，以及熔合区的面积和宽度。实验结果表明，不同焊接能量模式下小孔入口的工艺变化不同，主要差异来自小孔长度的变化。在不同形状的激光束焊接中，等离子体强度与小孔入口呈正相关。不同激光束的截面融合效率差异较大。这项工作为研究人员和工程师提供了一项新的研究，以更好地了解材料焊接中的成形激光束。