SiC自由曲面电解砂带抛光界面作用机理研究

To the problems of high difficulty of material removal, local easy deformation, fracture and low processing efficiency during the process of free-form surface forming for the light SiC mirror, the electrolytic dressing can achieve the characteristics of keeping the tool abrasive particle uniform and sharp, avoiding the blocking and forming the oxide film and reducing the tool wear, which combine the abrasive belt to remove the uniform distribution of local force. Two methods are integrated application to conduct the research the interaction of machining tool and material interface in the condition of multi-field coupling, such as force, thermal and chemical, during the free-form surface forming of SiC mirror. The research can reveal the failure process of abrasive belt and grinding fluid, the evolution rule of processing property, and influence rule of processing property on machining precision and surface quality, and then the optimization design and develop of machining tool and grinding fluid can be conducted. By researching the deformational behavior of inhomogeneous and variable flow direction material removal, fracture mechanism, stress and strain on processing area, surface quality prediction and rule of chip flow direction, the evolution mechanism of material surface and near-surface layer structure during the forming process can be revealed, and the scale effect of material transfer can be analyzed, and then the analytic model of material transfer theory can be established which suits for the free-form surface of SiC mirror. The physical and chemical behavior laws of belt electrolyte can be researched under the action of DC pulse. Finally, the corresponding technological parameters can be obtained by comprehensive experiment, which can improve the processing efficiency and surface quality.

针对轻薄SiC反射镜自由曲面成形过程存在的材料去除难度大、局部易变形和断裂破坏、加工效率低等问题，结合砂带去除局部区域作用力分布均匀，电解修锐可保持工具磨粒均匀锐利、防止堵塞且生成氧化保护膜、降低工具磨损的特点。综合应用两种方法来研究：SiC反射镜自由曲面成形过程中力、热和化学等多场耦合环境下加工工具与工件材料界面相互作用，揭示砂带和磨削液的失效形式、加工性能演变规律及其对加工精度和表面质量的影响规律，进行加工工具和磨削液的优化设计与研制；研究非均匀变流向去除材料的变形行为、断裂机制、加工区域应力应变、表面质量预测、磨屑流向规则等，揭示成形过程中材料表层及近表层材料结构演变机理，分析材料迁移的跨尺度效应，建立适用于SiC反射镜自由曲面的材料迁移理论分析模型；研究砂带与电解液在直流电脉冲作用下的物理化学行为规律。最终通过综合实验研究获得提高加工效率、改善表面质量的相应工艺参数。

针对轻薄SiC反射镜自由曲面成形过程存在的材料去除难度大、局部易变形和断裂破坏、加工效率低等问题，结合砂带去除局部区域作用力分布均匀，电解修锐可保持工具磨粒均匀锐利、防止堵塞且生成氧化保护膜、降低工具磨损的特点。综合应用两种手段来解决加工问题。首先，搭建了SiC自由曲面抛光机床的机械载体，研制了新型SiC自由曲面电解砂带成形的工具系统，确定了工具系统的结构、形状、尺寸，结构形式和实现机制。研究了机床精度的误差检测和补偿技术。研究了工具系统的调形控制方案和并进行了实验。研究了电解砂带制作过程和制作工艺，并进行了电解砂带的制作实验。通过SiC砂带磨粒磨抛过程的ABAQUS仿真和纳米压痕划痕实验，研究了去除材料的变形行为、断裂机制、加工区域应力应变、表面质量预测、磨屑流向规则等。通过综合实验，获得了提高加工效率、改善表面质量的相应工艺参数。本项目共发表论文6篇，其中SCI检索5篇，EI检索1篇。申报中国发明专利2项，其中已授权发明专利2项。获得软件著作权6项。该研究为解决SiC自由曲面加工工艺上的难题，提供了电解砂带修形抛光方面的新思路和新方法。