采用电荷耦合器件(CCD)高温检测技术,检测了送粉同步式和预置式两种不同工艺下Ni基合金激光熔覆熔池,得到了其在不同功率下的熔池形貌、尺寸和温度场分布。结果表明,当激光功率低于1100 W时,合金粉末熔化不均匀,熔池形貌不规则; 当激光功率达到1300 W时,熔池形貌近似椭圆形分布,比较规则平滑,x,y方向尺寸分别为2.8 mm,2.7 mm,平均温度为1800 K,其形貌和尺寸趋于稳定; 当激光功率继续增加时,熔池形貌基本不变,但平均温度增加,由于高温热传导熔化,熔池尺寸会有少量增加。

Based on charge-coupled device (CCD) technique for high temperature measurement, laser molten pool in laser cladding for Ni-base alloy powder was measured. Laser cladding experiments of powder feeding method and pre-fabricated powder method were carried out. Shape, size and temperature field distribution of laser molten pool were measured. It is shown that metal powder melt in part with rough molten pool shape when laser power was low than 1100 W. At 1300 W, the x,y dimensions of laser molten pool were 2.8 mm, 2.7 mm respectively with approximately ellipse shape, the average temperature was 1800 K. Its average temperature increased with small increase of shape dimension when laser power increased. Laser cladding parameters were optimized by the measurement results.