Study On Suitable Characteristic Parameters Of Metal Worn Surface Under Dry Condition

Tribology is an edge of the discipline on the study of interacting surfaces in relative motion between the friction, lubrication and wear, and the theory and practice of the relationship among the three aspects (including the design and calculation method of lubricating materials and lubrication, friction materials and surface conditions and friction fault diagnosis, monitoring and forecasting, etc.). State of the friction surface interaction can be a direct response to the situation of friction and wear. Therefore, numerous friction researchers paid more and more attention to the morphology of the friction surface in order to better reflect friction and wear properties.The suitable parameters of the surface morphology of metal materials on dry condition were investigated in this dissertation, these were used for reference on the workpiece machined surface morphology characterization of this field method, and could be better characterized based on the friction surface characterization after the two-dimensional and three-dimensional characterization of parametric analysis in order to propose three-dimensional metal surface characterization parameters of dry friction.In this dissertation, friction and wear tested in the HST-100 pin-disc wear testing machine, pin for the 45# steel, size ofΦ10mm×25mm; disk for GCr15, size ofΦ180mm. 45# steel pins on the friction and wear surface morphology were detected by German nanofocus three-dimensional surface profile measuring instrument. Tests were carried out under two conditions, one must load 20N, speed 20,30,40,50,60m/s; the other is the speed 20m/s fixed, loads 20,40,60,80,100N. Statistical regular pattern was found out after 10-times tests. Sliding distance for the test maintains 36000m. Before the test, respectively 180#, 500#, 1000# sand paper on pre-friction grinding, and then pin-disk to run, so that the contact friction was in good condition in order to reduce the initial state of the surface roughness that affects the experimental results.Finally, the friction and were morphology was collected by German nanofocus three-dimensional profiler by means of filter analysis. The conclusion is as follows: surface height deviation Sa, surface root mean square height deviation Sq and surface steepness Sku can be used as three-dimensional metal friction surface morphology of the basic parameters. They varies with the change of sliding speed and load ; with the change of friction coefficient and wear rate, there is a certain correlation; among three parameters, the correlation of surface steepness Sku and friction coefficient & wear rate is more evident. Namely, the larger the value of surface steepness Sku is, the narrower the width of steepness is, the more the relative number of steepness is, the larger the value of friction coefficient is, the least the value of wear rate is; however, the least the value of surface steepness Sku is, the wider the width of steepness is, the least the relative number of steepness is, the least the value of friction coefficient is, the larger the value of wear rate is.To sum up, the surface steepness Sku to characterize the surface morphology of friction and wear of metal materials under dry condition is more reasonable.