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为提高汽车零件冲压模具用导柱表面的耐磨性能,在导柱基材20Cr钢表面电沉积Ni-SiO_2纳米复合镀层。利用扫描电镜、能谱仪和透射电镜观察分析复合镀层的表面形貌、元素组成和显微组织,并利用显微硬度计和摩擦磨损试验机检测纳米复合镀层的硬度和耐磨性能。结果表明:纳米复合镀层的形貌质量较好,组织致密,平均晶粒尺寸为(50~100)nm;主要含Ni、Si、O等元素,其中SiO_2的质量分数约为7.8%;平均硬度约为660HV,是20Cr钢的1.1倍;耐磨性能优于20Cr钢,平均摩擦因数约为0.4,是20Cr钢平均摩擦因数的3/4。纳米复合镀层能够为20Cr钢提供有效的表面磨损防护,将纳米复合镀层用在汽车零件冲压模具用导柱上可提高导柱表面的耐磨性能。
In order to improve the wear resistance of guide posts on stamping dies of automotive parts, Ni-SiO 2 nanocomposite coatings were electrodeposited on 20Cr steel substrate. The surface morphology, elemental composition and microstructure of the composite coatings were observed by SEM, EDS and TEM. The hardness and wear resistance of the nano-composite coatings were measured by microhardness tester and friction and wear tester. The results show that the nanocomposite coating has better morphology, dense microstructure and average grain size of (50 ~ 100) nm. It mainly contains elements such as Ni, Si and O, with the mass fraction of SiO_2 being about 7.8% About 660HV, is 1.1 times 20Cr steel; wear resistance is better than 20Cr steel, the average friction factor of about 0.4, 20Cr steel is the average friction factor of 3/4. The nano-composite coating can provide effective surface wear protection for 20Cr steel, and the nanocomposite coating can be used to improve the wear resistance of the surface of the guide post by using the nano-composite coating on the guide post of the stamping die for automotive parts.