灰铁基Cr-n-Al_2O_3复合电刷镀层的性能

Properties of Cr-n-Al_2O_3 Composite Coatings Grown on Grey Cast Iron Substrates

采用电刷镀在灰口铸铁表面制备了n-Al2O3掺杂的Cr基复合镀层。通过X射线衍射仪(XRD)、扫描电镜(SEM)、扫描电子显微镜附带能谱仪(EDS)等技术对镀层的晶粒尺寸、截面与表面形貌及n-Al2O3在镀层中的分布进行了表征。此外,利用显微硬度计、磨损试验机、电化学工作站等仪器对镀层的硬度、耐磨性、抗腐蚀性等进行了测试。结果表明:Cr-n-Al2O3复合镀层组织致密无明显缺陷,n-Al2O3均匀地弥散分布于镀层表面;在纳米粒子的弥散强化及细晶强化作用下,复合镀层的硬度相对于纯Cr镀层提高了42.8%,耐磨性也有所提高;此外,n-Al2O3的加入也改善了镀层的耐腐蚀性能。

Cr-n-Al2O3 composite coating was grown on grey cast iron substrates by brush plating. X- ray diffraction （XRD） and scanning electron microscope （SEM） were employed to investigate the grain size and morphology of the coatings. Energy dispersive spectrometer （EDS） was used to analyze the distribution of n-Al2O3 in the surface of the coatings. In addition, hardness, wear resistance and cor- rosion resistance of the coating were also tested on microhardness tester, wear tester and electrochem- ical workstation. Results indicate that the composite coating presents compact structure, and there are no obvious defects. The addition of n-A1203 leads smaller grain size. With the dispersion-strengthe- ning and fine-grain strengthening effect,the Cr-n-Al2O3 composite coating exhibits enhanced hardness and improved wear resistance. The content of n-Al2 O3 also affects the corrosion resistance of the com- posite coating.