为解决激光熔覆成形不等宽构件多道搭接产生的冷却不均匀、产生开裂等缺陷问题, 提高激光熔覆成形不等宽熔道的成形效率及成形质量。基于光内送粉方式在单道工艺中采用实时变激光光斑方法, 一次扫描而非多道搭接直接熔覆出不等宽熔道。实验结果表明: 在保证送粉量足够条件下, 变光斑过程中通过实时变扫描速度, 能够直接熔覆出高度增长一致, 宽度逐渐变化熔覆层; 随熔道宽度逐渐变宽过程中, 熔覆层显微组织树枝晶大小逐渐变细。为光内送粉激光熔覆成形薄壁变壁厚类零件的工艺提供指导。

To solve the cladding layers’ defects of uneven cooling, cracking during laser cladding forming process, we propose a variable laser spot method to fabricate single-track cladding layers with unequal width by the inside-laser powder feeding. The experimental results show that the cladding layers can be fabricated with uniform height and variation width gradually by adjusting shielding gas pressure, laser power and scanning speed in real time during variable laser spot process under enough powder feed rate condition. And the dendrite size of the cladding layers’ microstructure is becoming thin gradually with the increasing width of lading layers. The research results will expect to provide a process guidance for thin-wall unequal width parts fabricated using laser cladding forming technology by laser-inside powder feeding.