缸套-活塞环摩擦状态转化形貌特征演变规律分析

Analysis of Cylinder Liner-Piston Ring Surface Morphology Variation During Friction Condition Transition

针对柴油机缸径为110,mm珩磨铸铁缸套在润滑不良时的拉缸问题,通过设计贫油试验,获得往复运动行程止点附近在不同摩擦阶段的表面形貌,以自相关函数表征取向特征,以分形维数表征表面形貌在各个方向的分形特征,量化描述表面形貌在摩擦状态转化过程中的演变规律.结果表明:从停止供油到发生黏着磨损,自相关函数幅值逐渐增大,摩擦表面的取向特征逐渐增强;分形维数在摩擦表面各方向上逐渐减小,精细复杂程度降低.在黏着磨损发生前,缸套表面形貌经历了"抛光"阶段,各向分布的分形维数趋近于1.5.

To study the scuffing problems of honed cast iron cylinder liners with 110,mm bore in diesel engine,the surface morphology at different friction conditions were obtained at top dead center through the starved lubrication experiments. Three dimensional characterization techniques were used to form the comprehensive characterization of cylinder liner wear process. Autocorrelation function and profile dimensional distribution of surface morphology were used to indicate the changes in the topographic features during the friction condition transition. Results show that from lubricant starvation to the adhesive wear condition,surface orientation is gradually strengthened and the amplitude of autocorrelation function is increased. Moreover,the decreased profile fractal dimensions in all directions are decreased. Prior to the occurrence of adhesive wear,the surface topography of cylinder liner experiences a 'polishing' stage with its distribution of fractal dimensions close to 1.5.