Study On The Tribological Properties And Wettability Of Plastic Deformed Interface

In the process of machining,the workpiece and tool and lubricant on the contact interface form a complex mechanism of friction and lubrication.A series of wetting and frictional experiments were carried out in order to investigate the effect of surface topography of aluminum alloy on the frictional properties and wettability of the interface,as well as establish the relationship between the wettability and friction.The aluminum alloy samples with 0°,45°,90° of textural directions were obtained by cutting,then manufactured microcavity with different area density on the surface.The wetting experiments were conducted with 32#mechanical oil on the Optical Contact Angle and Surface Tension Meter SL200KS,and a series of frictional experiments were carried out with different contact pressures under oil lubrication on a tailored friction tester.The three dimensional surface topography of samples before and after tests were measured by non-contact 3D Optical Profiler Talysurf CCI Lite,and establish a quantitative relationship between the surface topography and the wettability and the friction by choosing such parameters as S_a,S_tr,S_sk,S_dq,V_vv and V_vc,then make a further analysis of the correlation between the wettability and friction.The experimental results show that the aluminum alloy exhibits anisotropy in the process of wetting and friction due to different surface texture direction,the wettability of parallel textural sample is the best,while the friction coefficient is the largest;the wettability of vertical textural sample is the worst,while the friction coefficient is the smallest.And the microcavity with different area density on the surface can weaken the effect of texture direction on the wettability and contact interface friction,which reflects the coupling effect of surface mirocavity and texture on the interface wettability and friction.There is a regular relationship between surface morphology and wettability and friction,the surface with smaller Ssk,Str,Sdq has the better wettability;the surface with larger S_tr,V_vv,V_vc and smaller S_sk shows lower friction coefficient.Based on the experimental results and three-dimensional characterization parameters to analyze the relationship between the wettability and friction,the tribological properties of the sample surface are affected by the surface topography and wettability.The above conclusions provide a basis for the optimization of surface topography.