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

在工程应用中，存在着较低硬度表面比较高硬度表面耐磨性更好的现象，为了弄清其原因，用固定磨粒和活动磨粒分别研究了磨损过程中较低硬度基体表面的强化效应，在给定的试验条件下，固定磨粒和活动磨粒都能够在试件表面形成磨粒－铁复合材料层，从而使表层材料的硬度提高、耐磨性改善，使用寿命延长，其中固定磨粒的粒度越大，越有惠于复合材料层的形成；活动磨粒造成的增重效果更加明显，而且复合材料层也比较厚。复合材料层的开成

An Examination of Mechanism and Influencing Factors of a Composite Material Layer Formed in the Abrasive Wear

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.