激光工艺参数对纳米SiO2复合镀层组织性能的影响

The Effect of Laser Processing Parameters on Microstructure and Performance of Nano-SiO_2 Composite Plating Layer

在H13钢表面通过纳米复合电刷镀的办法预置均匀分布的纳米SiO2镀层,然后通过高功率连续CO2激光处理预置表面,采用扫描电子显微镜(SEM)观察了镀层处理前后表面形貌,测试了处理后镀层显微硬度的变化,结果表明:激光工艺参数能有效影响覆层表面形貌和硬度。通过激光处理,不仅可使纳米复合镀层的菜花头形状变成多变形晶粒,而且可以消除镀层间隙。在激光功率和速度比值为2的条件下,功率一定时,随扫描速度增加硬度上升;扫描速度一定时,随着激光功率增加硬度增加。试验优化后的最佳值为:功率参数为:2.0kW≤P<3.1kW,扫描速度参数为:0.8m/min≤Vs<2m/min。

Nano-SiO2 composite coating was made on the surface of H13 steel, then it wass treated by high power continuous wave （CW） CO2 laser. The surface morphology before and after treatment was observed by Scanning Electron Microscope （SEM）, the distribution of micro-hardness was measured too. It wa shown that the hardness of cladding and surface morphology were influenced by laser processing parameters. Nano-composite plating like cauliflower was changed into polygonal grains and cracks along grain boundaries were eliminated after laser treatment. Keeping the ratio of laser power and velocity as 2, and power parameter as constant, the hardness was enhanced with the increase of scanning velocity. While the scanning velocity was constant, the hardness was enhanced with the increase of power. The optimal parameters were given as follows： the power parameter was between 2.0 and 3.1 Kw, and the scanning velocity was between 0.8 and 2 m/min.