激光深熔焊接过程中小孔径向尺寸及其动特性

通过对小孔同轴视觉图像的处理提取出小孔径向尺寸，研究了小孔径向尺寸随焊接规范参量变化的动特性。研究结果表明，小孔径向尺寸在工件未焊透时随激光功率的增大而增大，在焊透时小孔径向尺寸随激光功率的变化较小；随着焊接速度的增加，小孔的径向宽度逐渐减小，而其长度有一个先减小后增大再减小的波动过程；离焦量在一定的范围内，在足够高的激光能量密度下，激光辐照范围的增大使得小孔径向尺寸与激光光斑同步变化。

Radial Dimension of Keyhole and its Dynamic Characteristics in Laser Deep Penetration Welding

The radial keyhole size is acquired by processing the coaxial image of keyhole captured in Nd∶YAG continuous wave (CW) laser deep penetration welding, and its dynamic characteristics are studied in this paper. The studied results show that the radial dimension of keyhole increases with laser power for partial penetration, while it is nearly unvaried when the workpiece is fully penetrated. With welding speed increasing, the radial width of keyhole monotonously decreases, but radial length of keyhole will be fluctuated. In certain range of defocusing distance, if laser intensity is high enough, the expansion of irradiated area by laser beam can make the radial keyhole size synchronously increase with laser spot.