Research On Tribological Properties Of The Laser-Textured Surface With Micro-pores

Surface topography has great influence on the friction and wear behavior of tribopairs. Micro surface texturing as the means for improving tribological properties of mechanical components is increasingly concerned by researchers worldwide in recent years.Based on the analysis of several technologies of surface texturing, Laser Surface Texturing is selected in this thesis, Laser process has many outstanding characteristics such as non-contacting manufacturing, high working efficiency and no special material needed, and has become a preferred method in the field of surface texturing. The paper reviews the research of current state at home and abroad, and finds that most of work about micro-pores' application were conducted at the face contact sliding interface. So, this research emphasis on the effect of the regular micro-pores on the tribological behavior at the line contact sliding interface.The Nd:YAG laser is used to generate micro-pores on surface, and surface topography is measured. Tribological experiments are conducted on a MHK-500 ring-block tribometer. The differences in the tribological behaviors of the smooth and cancave surfaces are investigated respectively. The influence of micro-pores with different parameters, such as area density and diameters and depths on the tribological behavior is analyzed. The experimental results indicate that compared with the non-textured surfaces, the surface with appropriately designed regular micro-pores exhibits lower friction coefficient and temperature rise, otherwise, the tribological behavior would be worsened if the concaves were too large or small. The area ratio is related to the different real contact area and average oil film pressure. The regular concave with a diameter larger than the contact line width calculated on the Hertizan stress theory is recommended. When the ratio of the dimple depth over diameter is 20%, the dimples can lead to dramatic reductions in friction at line contact sliding friction. Since the contact area is limited at the line contact interfaces, diameter and area density of micro-pores have influence on quantity and average lubricant pressure in the contact region, thus the three parameters diameter ,depth, and area density that characterize the dimples should be selected systematically, in order to reduce the friction effectively.The results of this dissertation offer test data and design reference for the laser surface texturing applied to line contact industrial field.