航天惯性器件用SiCp/Al结构件高效超精密加工控制与优化

As the aerospace instrument materials with high performance, high volume fraction SiCp/Al composites have begun to be applied in the field of aerospace in China. However, their machining process is much more difficult than traditional metal materials, and the machining mechanism is more complex. Especially，in the existing machining conditions, matrix tearing, edge chipping, cracks, hole defect, low machining efficiency and severe tool wear, which directly affect the machining quality, machining precision and working performance of SiCp/Al structural parts. .Therefore this project intends to apply the ultrasonic vibration machining into high-efficient ultraprecision machining for SiCp/Al(volume fraction: 40%) structural parts of aerospace inertial devices, analyze materials removal mode of SiCp/Al under ultrasonic vibration, establish the ultrasonic vibration machining cutting force model, reveal the damage formation mechanism of SiCp/Al during ultrasonic vibration machining. Aiming at the typical characteristics of aerospace inertial device components such as thin-walled cylinder, deep hole and small hole thread, the process research is carried out to develop high quality, low stress turning and boring technology and high efficiency, low damage drilling and tapping process for SiCp/Al. At the same time, machining process of SiCp/Al typical structural parts such as float and frame of three-floated gyro will be optimized and validated. The above work will provide an effective solution for the high-efficient ultraprecision machining of SiCp/Al structural parts for aerospace inertial devices.

高体积分数SiCp/Al复合材料作为高性能航天仪表材料已在国内航天领域初步开展应用，其切削加工比传统金属材料更为困难，加工机理更为复杂。在现有加工工艺条件下，易出现基体撕裂、崩角、裂纹、孔洞等缺陷，加工效率低下，刀具磨损严重，直接影响到了SiCp/Al结构件加工质量、加工精度和使役性能。. 本课题拟将超声振动加工应用于航天惯性器件用高体分SiCp/Al（体积分数40%）结构件高效超精密加工，分析超声振动作用下的SiCp/Al材料去除模式，建立切削力模型，揭示SiCp/Al加工损伤形成机制；针对航天惯性器件结构件薄壁圆筒、小孔及螺纹等典型特征开展加工工艺研究，提出SiCp/Al高质量低应力车削、镗削工艺方法和高效率低损伤钻孔、攻丝工艺方法；对高体积分数SiCp/Al三浮陀螺仪浮筒、框架等结构件进行加工工艺优化和验证，为航天惯性器件用SiCp/Al结构件的高效超精密加工提供有效解决途径。

高体积分数铝基碳化硅（SiCp/Al）复合材料作为高性能航天仪表材料已在国内航天领域初步开始应用，但是由于碳化硅硬质相的加入，其切削加工比传统金属材料更为困难，加工机理更为复杂。在现有加工条件下，易出现基体撕裂、崩边、裂纹等缺陷，加工效率低下，刀具磨损严重，直接影响到了结构件加工质量、精度和使役性能。本项目针对超声振动加工航天惯性器件用高体分SiCp/Al复合材料变形和去除机理、高效超精密加工工艺等科学及技术问题开展了全面、系统的研究并取得了显著的成果。.在机理方面，本项目开展了SiCp/Al超声振动压缩试验，获得了压缩应力应变变化规律，观测并分析了断面的形貌和组织变化，发现了SiCp/Al在超声振动作用下流动应力和抗压强度降低的“声学软化”效应；开展了单颗金刚石超声振动划擦SiCp/Al仿真及试验，模拟了SiC颗粒和铝基体在超声振动作用下的材料去除过程，获得了高速加工时超声振动参数与加工参数的匹配关系，揭示了超声振动断续切削机制对材料去除的作用；开展了SiCp/Al超声振动辅助磨削试验，获得了超声振动作用下SiCp/Al延/脆性去除模式工艺参数范围，提出了SiCp/Al超声振动磨削延脆性去除模式调控方法，建立了考虑刀具特性和材料去除特性的超声振动辅助磨削力模型，实现了SiCp/Al旋转超声振动亚微米级表面加工。.在机理研究的基础上，开展了SiCp/Al超声振动加工工艺特性研究，并研制了系列专用超声加工装备：超声振动工作台、非共振型超声椭圆振动车削装置以及纵扭超声振动加工装置，并分别针对制孔加工、薄壁件外圆加工以及螺纹加工开展了工艺试验及参数优化研究，实现了SiCp/Al结构件典型特征的高效精密加工。本项目相关研究和技术成果实现了多件高性能航天仪表结构件的加工，为SiCp/Al复合材料超声振动加工技术迈向工业应用奠定了基础。