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在H13钢表面通过纳米复合镀(NCP)的办法预置纳米Al2O3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及截面形貌,利用X射线能谱(EDS)仪、X射线衍射(XRD)仪对处理前后的镀层进行了元素分析和物相分析,测试了处理前后镀层显微硬度及磨擦系数的变化。结果表明,激光处理后,强化层表面平整光滑,与基体形成冶金结合,成分均匀,组织细密。纳米Al2O3颗粒均匀分布在强化层表面,强化层显微硬度为原镀层的1.5~1.8倍,强化层摩擦系数约为镀层的1/2,基体的1/3。强化层和基体的表面主要以磨粒磨损为主,而纳米复合镀层则是磨粒磨损和黏着磨损综合作用的结果。
The surface of H13 steel was pre-coated with Nano-Al2O3 by nano-composite plating (NCP), and then the surface was pretreated by high-power continuous CO2 laser. The surface and cross-sectional morphology of the coating were observed by scanning electron microscopy X-ray diffraction (XRD) and X-ray diffraction (XRD) were used for the elemental analysis and phase analysis of the coatings before and after the treatment. The changes of microhardness and friction coefficient of the coatings before and after the treatment were tested. The results show that after laser treatment, the surface of the strengthening layer is smooth and smooth, forming a metallurgical bond with the matrix, with uniform composition and fine structure. Nano-Al2O3 particles are uniformly distributed on the surface of the reinforcing layer, the micro-hardness of the reinforcing layer is 1.5 to 1.8 times that of the original coating, and the coefficient of friction of the reinforcing layer is about ½ of that of the coating and 1/3 of the substrate. The surface of the strengthening layer and the substrate are mainly abrasive wear, while the nano-composite coating is the result of the combination of abrasive wear and adhesive wear.