织构化纹理对于45钢摩擦学性能的数值模拟及试验分析

Numerical Simulation and Experimental Analysis of Tribological Properties of 45 Steel with Surface Texture

为探究不同形式的微织构对于柴油发动机活塞裙部表面摩擦特性的影响,在考虑惯性效应的条件下,基于CFD方法,利用Navier-Stokes方程建立了织构化试样流场的二维仿真分析模型。利用磨床在试样表面加工出规律单向条状纹理,采用激光打标机在45钢表面制备三角微织构凹坑,并在MMW-1A立式万能摩擦磨损试验机上对织构化45钢进行摩擦试验。织构化流场的数值模拟试验结果表明:在织构化流场存在流体惯性效应,使得流场获得额外的承载力;条状纹理与三角微织构凹坑之间的流场存在惯性效应的"叠加"效应,能够获得更高的承载力。摩擦试验结果表明:带有条状纹理的上试样能够有效降低摩擦过程初始阶段的摩擦系数,缩短摩擦副达到稳定磨损状态的时间。摩擦试验结果较好地证明了数值模拟试验的准确性。

In order to investigate the effect of different forms of microtexture on the friction characteristics of the piston skirt surface of diesel engines,a two-dimensional simulation analysis model for the textured sample flow field was established with using the Navier-Stokes equation based on the CFD method in the consideration of the inertia effect.A regular unidirectional strip texture was processed on the surface of the sample using a grinder,a laser marking machine was used to prepare the triangular microtexture pits on the surface of 45 steel,and the friction test of textured 45 was carried out on the MMW-1A vertical universal friction and wear testing machine.The numerical simulation results of textured flow field showed that the fluid inertia effect existed in the textured flow field,so that the flow field obtained additional bearing capacity;the flow field between the strip texture and triangular microtexture pits had the inertia effect of"superposition",producing a higher bearing force.The results of the friction experiments suggested that the upper specimen with strip texture could effectively reduce the friction coefficient in the initial wear stage and shorten the time for the friction pair to reach a stable wear state.Besides,the results of the friction experiments proved the good accuracy of the numerical simulation experiments.