An Examination of Mechanism and Influencing Factors of a Composite Material Layer Formed in the Abrasive Wear
磨粒磨损中基体表面形成复合材料层的作用机理及其影响因素的考察

A phenomenon is present in the industrial applications that the surface with lowerhardness shows a better wear-resistance than the surface with higher hardness. In order to clarify itsmechanism,the surface strengthening effect of a substrate with lower hardness in wear process wasinvestigated by using the fixed and free abrasives separately. Under the given test condition,boththe fixed and free abrasives can form an abrasive/iron composite mate rial layer on the surface ofspecimens,in consequence,their hardness and wear-resistance can be increased and their servicelife can be lengthened. The bigger the fixed a brasives,the casier the formation of this compositematerial layer. The effect of in creasing weight is m ore obvious for the free abrasives,and thethickness of the composite lay er is al so larger.The formation mechanism of composite layer ismainly due to the embedmen t and crack of abrasives and mixing with the iron substrate in thedeformation process induced by other big a brasives.The analvsis by EDX found that the ratios ofabrasives to iron in the composite layers are 2:1 regardless the abrasives are fixed or free,becausethe composite layer will peel off due to the damage of continuity of iron substrate when this ratiowas surpassed.Therefore,this surface strengthening measure by forming a composite material layercan be employed in practice very e conomically for lengthening the service life of machinecomponents in the condition of not too severe abrasive wear.