叶片用316L不锈钢表面激光合金化铬涂层性能及参数优化

Synthesis and Characterization of Laser-Ablated Cr-Alloy Coatings on 316L Stainless Steel

采用激光合金化方法在叶片用316L不锈钢表面制备铬涂层性能,并进行组织性能测定以及参数优化。研究结果表明:铬涂层合金化层为月牙状的结构,是一种网状的柱状晶形态。在中形成了具有较大宽度的枝状晶组织形态。在X射线衍射谱图上形成了Fe-Cr与Cr_xFe_y对应的各个衍射峰。硬度表现为由合金化层往基体方向具有明显梯度分布的特征。当激光功率增大后,将会引起铬合金层硬度与厚度的上升;当增大激光扫描速率后,铬合金层发生了硬度先增大后减小的现象,而厚度表现为持续减小的情况;当涂层的厚度增大后,将会引起铬合金层的硬度发生减小的现象,厚度开始增大。确定316L不锈钢表面激光合金化铬涂层最优工艺:激光功率5.5 kW,扫描速率8.5 mm/s,涂层厚度0.15 mm。

316 L stainless steel was surface modified with Cr-alloy thin film,synthesized by laser ablation of Cr-alloy paste layer.The influence of the power and scanning-speed of laser on the microstructures and tribological behavior of the Cr-alloy films was investigated with X-ray diffraction,scanning electron microscopy and mechanical probes.The results show that the scanning-speed/power of laser and paste-layer thickness had a major impact.For instance,as the laser power increased,the hardness and thickness increased of the Cr-alloy films,comprising columnar grains;as the scanning speed increased,the thickness decreased and the hardness changed in an increase-decrease manner.However,as the paste-layer thickness increased,the thickness of Cr-alloy film increased,accompanied by a decrease of the hardness.The optimized laser ablation conditions included:a laser power of 5.5 kW,a scanning speed of 8.5 mm/s and a Cr-alloy paste thickness of 0.15 mm.