碳纤维陶瓷基复合材料超声振动磨削表面创成及亚表面损伤抑制机理研究

The high efficiency and low damage machining of carbon fiber reinforced ceramic matrix composites has become an important and difficult issue in aerospace field. With respect to overcome the technology issue in high efficiency and low damage ultrasonic vibration grinding of carbon fiber reinforced ceramic matrix composites, brittle-ductile removal mode evolution mechanism and migration condition of carbon fiber reinforced ceramic matrix composites under mechanical-ultrasonic compound energy field were studied; By establishing the surface damage characterization method for surface integrity, the surface and subsurface damage formation mechanism of carbon fiber reinforced ceramic matrix composites in ultrasonic vibration grinding process were studied, damage-free technical measures of surface damage and critical conditions in ultrasonic vibration grinding were carried out; the influence of material performances, ultrasonic vibration parameters, grinding parameters, grinding wheel parameters on surface integrity and material removal rate were also studied, and then the mapping relationship between ultrasonic vibration grinding process parameters and the machining efficiency, surface integrity was established, at last, optimized processing parameters for ultrasonic vibration precision grinding of carbon fiber reinforced ceramic matrix composites were proposed in order to overcome high efficient and low damage processing issue. The results of the project have important theoretical significance and application value for improving machining accuracy and surface integrity of carbon fiber reinforced ceramic matrix composites.

碳纤维陶瓷基复合材料的高效低损伤加工已成为我国航天领域发展的重点和难点问题。本项目针对碳纤维陶瓷基复合材料高效低损伤超声振动磨削技术问题，研究机械-超声复合能场作用下碳纤维陶瓷基复合材料脆塑性去除模式演变机理及迁移条件；通过建立面向表面完整性的表面损伤量化表征方法，研究碳纤维陶瓷基复合材料超声振动磨削表面创成与亚表面损伤形成机理，探寻减免亚表面损伤的技术措施，提出低损伤超声振动磨削加工的临界加工条件；研究材料性能、超声振动参数、磨削加工参数、砂轮参数等对加工表面完整性、材料去除率的影响规律，建立超声振动磨削工艺条件与加工效率、表面完整性的映射关系，提出碳纤维陶瓷基复合材料超声振动精密磨削加工优化工艺条件，解决碳纤维陶瓷基复合材料高效低损伤加工难题。项目成果对提高碳纤维陶瓷基复合材料零部件的加工精度和表面完整性具有重要理论意义和应用价值。

针对碳纤维陶瓷基复合材料高效低损伤精密加工难题，本项目系统研究了碳纤维陶瓷基复合材料超声振动磨削表面创成及亚表面损伤抑制机理。进行纵-扭复合超声辅助磨削的砂轮运动学分析，揭示了纵向振动和扭转振动对有效切削时间的影响规律；建立了纵-扭复合超声辅助磨削力模型；获得了陶瓷基复合材料在不同工况下，脆-塑性变形的力学响应，结合超声辅助刻划试验，揭示了陶瓷基复合材料脆-塑性材料去除机理；建立了纵-扭超声辅助磨削陶瓷基碳纤维增强复合材料的表面形貌重构模型；确定了超声辅助磨削复合材料的基体和纤维的损伤失效模式；揭示了超声辅助磨削复合材料的脆塑转变去除机理，确定了脆塑转变的临界切削力在5N左右；获得了不同加工目标的优化工艺参数。本项目的研究为碳纤维陶瓷基复合材料高效低损伤精密加工提供了新的工艺原理和理论基础。