高精度不锈钢微织构的椭圆振动金刚石切削加工机理研究

Surface texturing is a promising approach for controlling the friction between rubbing surfaces in mechanical components. For the ultra-precision machine tool industry, textures have the advanced application in improving the positioning accuracy of the hydrodynamic guideways. In particular, ultra-precision diamond cutting has be considered as a promising manufacturing method to fabricate surface textures with high accuracy and reproducibility. However, the ordinary diamond cutting can not be directly applied to stainless steel machining due to the severe thermochemical tool wear. In this work, the elliptical vibration cutting with a single crystal diamond tool is applied to the fabrication of micro textures on stainless steel. The mechanism of textures generation was investigated in detail by the FEM simulation with considering the mechanism of elastoplastic, material and tribology. The machined surface quality and the fabricated surface profile of textures were clarified. Moreover, the influence of vibration locus on the textures’ profile accuracy was quantitatively investigated. Hence, an amplitude control compensation method was proposed to decrease the machining error in texturing process. With the above-mentioned achievements, the experimental verifications of texture fabrications and friction tests were finally carried out. This work sheds much light on an interesting and promising manufacturing technique to fabricate surface textures for friction reduction between rubbing surfaces in mechanical elements.

表面功能微织构可以有效的控制机械部件滑动表面间的摩擦力，对于提高超精密机床不锈钢液压导轨关键部件的定位精度具有广阔的应用前景。虽然近些年来金刚石超精密切削技术已发展成为高精度微织构制造的一种有效方法，然而不锈钢是一种易与金刚石发生热化学反应导致刀具急剧磨损的难加工黑色金属材料，普通的金刚石切削方法难以直接用于不锈钢的超精密微细切削。本项目将椭圆振动金刚石切削加工技术应用于制备不锈钢表面高精度微织构，开展有限元仿真和实验研究，基于弹塑性力学、材料力学和摩擦学详细阐明微织构创成机制；随后系统研究刀具振动轨迹对微织构形状精度的影响机制，揭示不同振动轨迹对微织构加工精度的定量映射影响关系，提出可控振幅误差补偿方法并开展实验验证。本项目的研究为超精密机床滑动部件间降摩擦微织构的高精度制造提供了一种重要的技术手段。

本项目主要以降低机械部件滑动表面间的摩擦力为目标，研究椭圆振动金刚石切削加工技术在制备不锈钢表面高精度功能微织构表面的加工机理和工艺技术。具体开展了不锈钢微织构椭圆振动金刚石切削加工有限元仿真研究并进行实验验证，揭示微织构表面创成机制；基于椭圆振动切削过程中刀具运动学方程，构建刀具振动运动轨迹模型，数值解析微织构的成形轮廓，揭示不同振动轨迹对微织构加工精度的定量映射影响关系；随后开展不锈钢表面高精度微织构的制备工作并进行摩擦特性实验验证，自主研制高频高精椭圆振动切削装备，将自研装置装备于超精密加工机床，验证振幅补偿后的高精度微织构成形机制。最后开展摩擦特性实验，评价不同面形精度微织构功能表面的摩擦特性。理论与实验验证微正弦波凹坑具有最优降摩擦性能，摩擦系数约降低至平面接触的25%。本项目为不锈钢表面高精度微织构加工机理及方法为超精密机床滑动零部件间摩擦力的精确控制提供技术保障。