剪切流变辅助阶进式磨-抛高效精密加工方法研究

Aiming at the problem of long polishing cycle of grinding induced damage for hard and brittle materials, a shear rheology assisted progressive grinding-polishing method is proposed in this project. The shear rheological grinding-polishing fluid is developed to replace traditional grinding fluid, and the grinding wheel-workpiece contact state is controlled from contact to near-contact and to no-contact. Based on the shear rheological effects of grinding-polishing fluid, low-damage grinding, combined machining of grinding and polishing, and in-situ flexible polishing is finished orderly, and the near-lossless surface is obtained efficiently. By the combination of theoretical analysis, numerical simulation and experimental study, the shear rheological mechanism of shear rheological grinding-polishing fluid is investigated, and its characteristic detection and evaluation method is developed. The inhibition mechanism of grinding surface damage under hydrodynamic pressure is revealed, and an inhibition strategy for grinding surface damage is proposed. The action mechanism of free abrasive with the grinding wheel and the workpiece surface is explored, and the dressing and polishing mechanism resulted from shear rheological effects is revealed. The influence of process parameters and grinding-polishing liquid parameters on the machining efficiency and quality under different grinding wheel-workpiece contact states is investigated, and the main control factors of the grinding-polishing process is determined. Finally, high-efficiency precision grinding-polishing of typical hard and brittle material surface is finished. This project has important theoretical significance and engineering application value in enriching precision/ultra-precision machining technology.

针对硬脆材料磨削表面损伤大导致后续抛光时间长的难题，本项目提出一种剪切流变辅助阶进式磨-抛高效精密加工方法：用剪切流变磨抛液替代传统磨削液，并控制砂轮与工件“接触-准接触-非接触”状态阶进式变化，利用磨抛液的剪切流变效应依序实现“低损伤磨削-复合磨抛-原位柔性抛光”，进而高效获得近无损伤表面。本项目结合理论分析、数值模拟与工艺实验，研究剪切流变磨抛液的剪切流变机理，建立其特性检测评价方法；揭示砂轮-工件接触弧区剪切流变流体动压对磨削表面质量的影响机理，提出磨削表面损伤主动抑制策略；探究磨抛液柔性把持游离磨粒与砂轮、工件表面的作用机制，明确剪切流变效应下的砂轮修锐、工件抛光机理；研究不同砂轮-工件接触状态下，工艺参数及磨抛液性能参数对加工效率和质量的影响规律，确定阶进式磨-抛过程的主要控制因素；最终实现典型硬脆材料表面高效低损伤加工，丰富精密超精密加工技术，具有重要的理论意义和工程应用价值。

针对硬脆材料磨削表面损伤大导致后续抛光时间长的难题，本项目提出一种剪切流变辅助阶进式磨-抛高效精密加工方法。用剪切流变磨抛液替代传统磨削液，并控制砂轮与工件“接触-准接触-非接触”状态阶进式变化，利用磨抛液的剪切流变效应依序实现“低损伤磨削-复合磨抛-原位柔性抛光”，进而高效获得近无损伤表面。项目研制了以多羟基聚合物水溶液为基液的剪切流变磨抛液，并对其流变、防腐、抗沉降等性能进行了优化；研究了硬脆材料磨削表面损伤特征与机制，基于仿真分析方法探究了流体动压对磨削表面损伤的抑制机理；开展了脆性材料剪切流变流体动压辅助磨-抛加工工艺实验，实现了脆性材料低损伤磨削、原位柔性抛光和砂轮的在线修锐。本项目的研究为硬脆材料低损伤磨粒加工提供了新的工艺原理和理论基础。