摘要
在2024铝合金上采用了二次浸锌的预处理方法,以化学镀镍,电镀铜作为过渡层的特殊工艺,再利用磁过滤脉冲偏压电弧离子镀技术制备了Zn/Ni/Cu/Cr/CrN多层梯度膜。利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、显微硬度仪和腐蚀测量仪等测试手段分析薄膜的成分、结构、表面形貌、显微硬度、耐腐蚀性等特性。结果表明:多层膜性能梯度分布,结构交替变化,从而减少膜基的内应力,提高了铝合金上CrNx涂层的结合力,能够有效的解决铝合金上镀硬质陶瓷膜的热适配和晶格错配度大的难题。表面氮化物多层膜均匀致密,未出现龟裂,颗粒的数量和尺寸大大减少。氮化物以CrN(220)为主要相,氮化物膜层的显微硬度达到2600 HV,是镍磷层的3倍,与铝基体相比,其表面显微硬度提高了22倍多,耐腐蚀性提高了400 mV。这样的CrNx薄膜能使铝合金表面具有高硬度和良好的耐腐蚀性,对轻合金表面涂覆超厚硬质膜具有一定的研究意义。
Zn/Ni/Cu/Cr/CrN muhiayer gradient films were deposited on 2024 Al alloy surface in a technological order of secondary zinc dipping as pretreatment, chemical Ni plating, Cu electroplating for transition layer and magnetically filtered PBAIP （pulse bias multi-arc ion plating）. Then, the films＇ composition, structure, surface morphology, microhardness and corrosion resistance were characterized with SEM,XRD, microdurometer and corrosion potentiometer. The results showed that the gradient distribution of film performance and alternating change of structure can decrease the internal stress of substrate and increase the bonding force between film and alloy surface, thus solving efficiently the problem of thermal adaptation to hard ceramic film due to coating on Al alloy and high lattice mismatching. The surface multilayer film containing nitrides is even and compact without fissures, and the number and size of grains decrease greatly. The CrN （220） is dominent in nitrides, and the surface microhardness of nitride layer is up to 2600HV, ie., 3 times that of Ni-P layer and over 22 times higher than the alloy substrate, with corrosion resistance improved by 400mV. The investigation we made is therefore of significance to a certain extent for depositing ultrathick hard films on light alloy surface.
出处
《真空》
CAS
北大核心
2008年第2期38-42,共5页
Vacuum
基金
教育部高等学校科技创新工程重大项目"活性基材表面改性工艺基础研究"支持
