微凹坑织构表面摩擦学性能的实验研究*

摘要

采用调Q半导体泵浦YAG激光器，利用“单脉冲同点间隔多次”激光微加工特殊工艺，在45＃钢试样表面加工出具有不同几何参数的表面织构。在UMT-2型多功能摩擦磨损实验机上，考察富油润滑条件下微凹坑的面积占有率和深度对摩擦因数的影响规律，并研究不同工况条件下织构试样表面摩擦因数的变化规律。实验结果表明：在高速轻载工况下，与未织构试样相比，微凹坑表面织构具有显著的减摩润滑作用；微凹坑的面积占有率为15％，深度为5μm时，摩擦副的摩擦因数最低，最大降幅约为50％；但在中速中载和低速重载的条件下，织构试样的摩擦因数反而大幅增加。对试样表面的磨损形貌的考察结果表明，微凹坑织构表面具有显著的抗磨耐磨效果。%By using a Qswitched diode-pumped NdYAG laser,micro-dimples with different geometrical parameters were textured on 45# steel surface by using a process named “single pulse at a time,repeated at intervals”. The effects of area density and depth of the micro-dimples on friction coefficient were studied on the condition of oil-rich lubrication,and the wear scar of surface was analyzed by using electronic scanning microscope. The experimental results show that,under the high speed and light load condition,the textured surface with appropriate micro-dimple parameters can obviously re-duce the friction coefficient compared with the untextured surface. The textured specimen with area destiny 15% and depth 5 μm of micro-dimples has the lowest friction coefficient,and the friction coefficient is reduced by 50% compared with the untextured specimen. However,under the medium speed and load and the low speed and heavy load conditions,the tex-tured specimens have higher friction coefficient compared with the untextured surface. By observing the wear scar,it is found that micro-dimple can obviously reduce the wear.