Abstract: Currently,more and more engine blocks are produced by cast aluminum alloys in automotive industry.For the poor wear resistance,cylinder liners made of gray cast iron are embedded to improve the tribological properties.A promising alternative to the use of cylinder liners is the application of wear-risistent coatings deposited by thermal spraying onto the cylinder bore walls.The two kinds of iron-based coatings were prepared by arc spraying.The microstructure and wear risistance of the coatings were analysed by OM,SEM,XRD and MMW-1 Vertical universal wear tester and chosed gray cast iron as a standard material for comparison.The wear tset was carried out under lubricated sliding conditions,sliding speed of 0.5m/s,sliding distance of 4500 m,and normal load of 200 N.The results show that,08A coating has satisfactory values of wear and friction and that it can be a substitution for gray cast iron liners.

Key words: Iron-based coating,    , Arc spraying,     , Microstructure,    , Wear scar,    , Porosity,    , Oxide,    , Wear risistant,    , Friction

摘要： 为节能减排,目前多采用铝合金制造汽车发动机体。由于铝合金耐磨性差,一般需要在气缸内嵌入灰铸铁缸套以改善摩擦性。采用热喷涂技术在气缸壁上喷涂一层耐磨涂层可以解决这一问题。采用电弧喷涂技术制备了两种铁基涂层。通过光学显微镜、扫描电子显微镜、X射线衍射分析仪分析了涂层的组织;利用MMW-1立式万能磨损试验机测试了油润滑条件下涂层的耐磨性,并与作为标准件的灰铸铁材料进行了对比。磨损试验参数为转速0.5m/s,滑行距离4500m,轴向力200N。结果表明:08A涂层的耐磨性和摩擦系数比灰铸铁好,可以替代灰铸铁缸套。

关键词: 铁基涂层,    , 电弧喷涂,    , 微观组织,    , 磨痕,    , 孔隙,    , 氧化物,    , 耐磨性,     , 摩擦系数