提出了基于控斑技术的机器人曲面激光熔覆轨迹规划方法,以光斑投影面积变化的阈值控制激光输入曲面上的能量密度。通过改变曲面轨迹插补点上激光束投影光斑的几何形态,分析了离焦量与姿态对熔覆质量的影响。实验获得了不同离焦量和姿态下的激光扫描路径,结果表明,在其他工艺参数不变的情况下,离焦量为5 mm时熔覆效果较好;当空间夹角为23.4°时,熔覆层出现裂纹;当空间夹角大于30°时,熔合线附近出现明显的夹杂、空洞;熔覆层的厚度随空间夹角的增大而减小,且总体硬度高于基材。通过光斑面积的变化,校验出轨迹插补点,进而控制姿态变化,实现在激光表面高质量的熔覆。

In this paper, a trajectory planning method for laser cladding of robot surface based on spot control technology is proposed. The energy density of laser input surface is controlled by the change threshold of spot projection area. The influence of defocus and attitude on the cladding quality is analyzed by changing the geometrical shape of laser beam projection spot on the surface trajectory interpolation point. The results show that the cladding effect is better when the defocusing amount is 5 mm, the cracks appear when the space angle is 23.4°; the inclusions and cavities appear when the space angle is more than 30°; the thickness of the cladding decreases with the increase of the space angle and the overall hardness is higher than that of the substrate. The trajectory interpolation points are verified by the change of spot area, and then the attitude change is controlled to achieve high-quality cladding on the laser surface.