初始表面粗糙度对沟槽织构摩擦性能的影响

目的探究初始表面粗糙度大小对激光沟槽织构化表面摩擦性能的影响规律。方法采用脉冲光纤激光器在不同粗糙度的45#钢试样表面制备具有不同深度、规则排列的沟槽织构,利用摩擦磨损试验机进行销-盘式往复摩擦试验,研究初始表面粗糙度对沟槽织构化表面摩擦系数的影响规律,以及不同初始表面粗糙度条件下,激光沟槽织构化表面的摩擦学行为。结果沟槽织构能够有效降低表面的摩擦系数,初始表面粗糙度、载荷和速度的大小对沟槽织构的润滑减摩性能有较大影响。在较低的载荷下,沟槽织构能有效提高表面的流体动压润滑效应;在较高的载荷下,沟槽织构能够有效改善表面的边界润滑性能。存在最优初始表面粗糙度,使得摩擦系数达到最小,初始表面粗糙度最优值的大小应根据载荷和速度大小来确定。结论根据摩擦副表面的载荷和速度工况条件,合理优化初始表面粗糙度能使沟槽织构获得较为理想的润滑减摩效果。

Effect of Initial Roughness on the Tribological Properties of Textured Surfaces with Micro-grooves

The work aims to investigate the influence laws of initial roughness on the tribological properties of laser mi-cro-groove textured surfaces. The regularly arranged micro-grooves were fabricated on the surface of 45# steel specimens with different roughness by pulse fiber laser. The pin-to-disc reciprocating test was carried out by friction and wear tester to study the influence of initial roughness on the friction coefficient of micro-groove textured surface and the tribological behavior of laser micro-groove textured surface under different initial roughness. The friction coefficient could be significantly reduced by groove texture. The initial roughness, load and sliding velocity had significant effect on the tribological properties of groove texture. Hydrodynamic lubrication could be significantly improved by groove texture under the lower load, and boundary lubrication could be effectively improved by groove texture at higher load. There was the optimal initial roughness to minimize the friction coefficient. The optimal value of initial surface roughness could be determined according to load and sliding speed. The ideal performance of friction reduction of the textured surfaces can be obtained by optimizing the initial surface roughness according to the load and speed.