论文部分内容阅读
现有激光熔覆技术大多是基于水平基面上开展的,这种方式极大地限制了激光熔覆技术的广泛应用。基于“光束中空、光内送粉”技术,通过对激光加工机器人系统的程序控制实现了基板0°~150°的倾斜和熔覆头相应姿态的连续变化,研究了基板不同倾斜角度下对熔覆层截面尺寸及组织的影响规律,并对变基面过程中的熔池进行了受力分析。实验结果表明:随基板倾斜角度逐渐增大,粉末聚焦特性变差,进入熔池的粉末量逐渐减少,造成熔覆层高度逐渐降低。熔覆层宽度稳定在光斑左右,变化不明显;偏移量(熔覆层最高点轴线位置偏离激光束轴线位置间的距离)先增大后降低。熔覆层顶部显微组织树枝晶大小先变粗后变细,典型柱状晶生长方向随基板角度变化也发生相应的倾斜。该工艺为在非水平基面上进行激光熔覆、修复及成形提供了参考价值。
Most of the existing laser cladding technologies are based on horizontal basal plane, which greatly limits the wide application of laser cladding technology. Based on the “beam hollow, light feeding” technology, the sequential tilting of the substrate and the corresponding attitude of the cladding head were realized by the program control of the laser processing robot system. The effects of substrate tilting angle The influence of cladding layer size and structure on the cladding layer was analyzed. The experimental results show that as the tilting angle of the substrate increases, the focusing characteristics of the powder deteriorate, and the amount of powder entering the melt pool decreases gradually, resulting in a gradual decrease in the height of the cladding layer. The width of cladding layer is stable around the spot, the change is insignificant; the offset (the distance between the highest point of the cladding and the axis of the laser beam) increases and then decreases. The dendrite size of the microstructure at the top of the cladding layer first coarsens and then becomes thinner. The growth direction of the typical columnar crystals also changes correspondingly with the substrate angle. The process provides a reference value for laser cladding, repairing and forming on the non-horizontal base.