高斯光束传播对激光熔覆覆层的影响

Influence of Gauss Beam Propagation on Laser Cladding Coating

高斯激光束传播对激光熔覆质量有显著影响。为探索高斯光束传播对覆层几何形貌、结合质量及稀释率的影响,以Fe901+5%Cr3C2熔覆材料为研究对象,对高斯光束不同离焦区域进行了激光熔覆工艺实验,对比了正、负离焦工艺。利用金相显微镜对熔覆层几何形貌、微观结构进行分析,并对显微硬度分布进行测试与对比。结果显示,采用负离焦工艺进行激光熔覆,可获得稀释率较低,边缘良好冶金结合,无未熔颗粒、缺陷的覆层,覆层显微硬度在900～1000 HV0.2。

The effect of Gauss beam propagation on the quality of laser cladding coating is dramatic, which includes sectional geometric pattern, bonding quality and rate of dilution of laser cladding layer. For exploring all above influences, the experiments of laser cladding in different defocused zone of Gauss beam were made, especially, the positive defocused zone and negative defocused zone were investigated, and Fe901 ＋5 % Cr3C2 was used as cladding material. By using metallographic microscope, the sectional geometric pattern and microstructure of coating were analysed in detail. Then, the microhardness distribution of each coating were tested and compared. The research showed that laser cladding layer in negative defocussing of Gauss beam had better properties such as low rate of dilution, good metallurgical bonding with base metal, and there is no unmelted metal particle and defect at the edge of coating. The microhardness Of cladding zone was 900-1000 HV0.2.