塑性成形接触界面间摩擦特性与润湿特性研究

发布时间：2018-07-08 21:35

本文选题：摩擦 + 润湿　；参考：《合肥工业大学》2017年硕士论文

【摘要】：在机械加工过程中,塑性成形接触界面间的工件、模具以及润滑剂之间形成了复杂的摩擦润滑机理。为了探讨试件表面形貌对接触界面间摩擦特性和润湿性的影响,并建立固液界面润湿性与表面摩擦特性之间的关联性,本文开展了润湿和摩擦试验研究。在纹理方向分别为0°、45°、90°的铝合金表面上加工不同面积占有率的规则圆形微凹坑,从而得到不同表面形貌的试样。选用32#机械油,采用SL200KS光学法固液接触角和界面张力仪针对试样进行润湿性测试;利用自制的摩擦试验装置,在油润滑条件下以不同接触压力对不同形貌的试样进行摩擦试验研究。利用Talysurf CCI2000白光干涉三维轮廓仪测量试验前后的试样表面,并选取S_a、S_(tr)、S_(sk)、S_(dq)、V_(vv)和V_(vc)等三维参数对试样三维表面形貌进行表征,从而建立表面形貌与摩擦和润湿之间的量化关系,并进一步分析界面润湿性与摩擦特性之间的关联。结果表明:表面纹理方向的差异导致铝合金表面在固液界面润湿和滑动接触摩擦过程中表现出各向异性,平行纹理试样润湿性最好,但摩擦系数最大;垂直纹理试样润湿性最差,但摩擦系数最小。而在其表面加工不同面积占有率的微凹坑,减弱了铝合金表面纹理方向性对界面润湿和摩擦的影响,反映出表面微凹坑和纹理对界面润湿性和摩擦特性的耦合作用。表面形貌与润湿性和摩擦特性之间有规律性的联系:S_(sk)、S_(tr)、S_(dq)越小,表面润湿性越好;S_(tr)、V_(vv)、V_(vc)较大,S_(SK)较小的表面,摩擦系数较低。基于试验结果与三维形貌表征参数分析润湿性与摩擦特性之间的关联可得,试样表面的摩擦性能受表面润湿性和表面形貌的综合影响。以上结论为表面形貌的优化设计提供一定的依据。
[Abstract]:In the process of machining, the friction lubrication mechanism is formed between the workpiece, die and lubricant in plastic forming contact interface. In order to investigate the effect of surface morphology on the friction characteristics and wettability of the contact interface, and to establish the relationship between the wettability of the solid-liquid interface and the friction characteristics of the surface, wetting and friction tests were carried out in this paper. The regular circular micropits with different area occupancy were machined on the surface of aluminum alloy with a texture direction of 0 掳~ 45 掳~ 90 掳, and the samples with different surface morphologies were obtained. The wettability of the sample was tested with SL200KS optical solid-liquid contact angle and interfacial tension instrument, and the self-made friction test device was used to test the wettability of the sample. The friction tests of samples with different morphologies were carried out under oil lubrication at different contact pressures. Using Talysurf CCI2000 white light interference three-dimensional profilometer to measure the surface of the sample before and after the test, and selecting three dimensional parameters, such as S _ S _ (tr) _ S _ (sk) _ S _ (dq) _ V _ (vv) and V _ (vc), to characterize the three-dimensional surface morphology of the sample, thus establishing the quantitative relationship between the surface morphology and friction and wettability. The relationship between the wettability of the interface and the friction characteristics is further analyzed. The results show that the surface of aluminum alloy exhibits anisotropy in the process of solid-liquid interface wetting and sliding contact friction due to the difference of surface texture direction. The wettability of parallel texture samples is the best but the friction coefficient is the largest. The wettability of vertical texture samples is the worst, but the friction coefficient is the smallest. The effect of grain orientation on interface wettability and friction of aluminum alloy surface was weakened by machining micropits with different area occupancy, which reflected the coupling effect of surface micropits and textures on interface wettability and friction characteristics. There is a regular relationship between surface morphology and wettability and friction characteristics. The smaller the surface wettability is, and the lower the friction coefficient is, the smaller the surface wettability is, the larger the V _ (vv) / V _ (vc) is, and the smaller the S _ (SK) is. The relationship between wettability and tribological properties can be obtained based on the experimental results and 3D morphology characterization parameters. The friction properties of the sample surface are affected by the wettability and the surface morphology. The above conclusions provide some basis for the optimization design of surface morphology.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG301

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