铝基非晶纳米晶复合涂层研究

采用自动化高速电弧喷涂系统,用自行研制的粉芯丝材,在AZ91镁合金基体表面上制备出Al-Ni-Y-Co非晶纳米晶复合涂层.采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、透射电子显微镜(TEM)分析了Al-Ni-Y-Co非晶纳米晶复合涂层的微观形貌和组织结构,结果表明Al-Ni-Y-Co非晶纳米晶复合涂层是由非晶相和纳米晶化相共同组成的,涂层结构致密,孔隙率约为1.8%.Al-Ni-Y-Co非晶纳米晶复合涂层的平均显微Vickers硬度值为311.7 HV0 1,结合强度为26.8 MPa.涂层的抗磨损耐腐蚀性能优于Al涂层和AZ91镁合金基体;其相对耐磨性约为Al涂层的10倍,为AZ91镁合金的6倍;其自腐蚀电位值正于Al涂层及AZ91镁合金,自腐蚀电流密度值约为Al涂层的1/2,AZ91镁合金的1/5;其腐蚀后的表面形貌比Al涂层和AZ91镁合金平整,点蚀较少.Al-Ni-Y-Co非晶纳米晶复合涂层的耐磨防腐综合性能优异.

STUDY ON Al-BASED AMORPHOUS AND NANOCRYSTALLINE COMPOSITE COATING

An Al-Ni-Y-Co amorphous and nanocrystalline composite coating was prepared on the surface of the AZ91 Mg alloy by using an automatic high velocity arc spraying system.Its microstructures were analyzed by scanning electron microscope(SEM),X-ray diffraction(XRD) and transmission electron microscope(TEM).The results show that the coatings compose of amorphous,nanocrystalline and microcrystalline phases,which has a compact structure with low porosity about 1.8%.The average Vickers microhardness and bond strength of this coating are 311.7 HVo.i and 26.8 MPa.Its relative wear resistance is about 10 times than that of Al coating and 6 times than that of AZ91 magnesium alloy.The corrosion potential of this coating is more positive than that of Al coating and AZ91 magnesium alloy,and the corresponding corrosion current density value is about 1/2 the same as that of Al coating and 1/5 as that of AZ91 Mg alloy.Especially,compared with the surface on corroded Al coating and AZ91 Mg alloy,the corroded Al-Ni-Y-Co coating has a more flattered surface with less corrosive piting than Al coating.It is confirmed that the Al-Ni-Y-Co coating is an excellent coatinig with higher wear-resistance and corrosion resistance.