离散化工程陶瓷高效低损伤超声辅助铣削基础理论与关键技术研究

Ultrasonic assisted machining is one of the effective methods of machining of the hard and brittle materials, and the multi-axis machining has the ability for high-performance machining of complex surface. Currently, the scientific mechanism and processing laws for ultrasonic assisted multi-axis milling of engineering ceramic remains to be further investigated. This project proposed the new ideas of discretizing the engineering ceramics by the laser precasting micro texture. Based on the multidisciplinary modeling and simulation, theoretical analysis, and combining with experimental study, the high efficiency and low damage ultrasonic assisted milling operation could be achieved by optimizing the key process factors group. This project intends to ascertain the influence law of laser parameters on the prefabricated micro texture features for several kinds of engineering ceramics materials. The crack initiation and propagation mechanism and control strategy for ultrasonic assisted milling of discrete engineering ceramics will be revealed, and detection and characterization of chip morphology will be carried out. The high frequency and dynamic physical field coupling model for ultrasonic assisted milling of discrete engineering ceramics will be established, and material removal characteristics and generation mechanism of machined surface will be clarified. In addition, simulation forecast and measure of the time varying rule of the material removal rate, cutting force and cutting temperature for ultrasonic assisted milling of engineering ceramics after discretization of machining region will be carried out. Moreover, this project will find out the influence law of the key process factors on the machined surface integrity, and analyze the high frequency and dynamic relationship between the cutter axis vector and tool-workpiece interaction characteristics. Finally, the machining mechanism driven multi-objective coupling process optimization will be conducted, and the processing application will be carried out, which could provide theoretical guidance and technical support for ultrasonic assisted milling of engineering ceramics with high efficiency and low damage.

超声加工是硬脆材料加工的有效方法之一，多轴加工可高性能加工复杂型面。目前，关于工程陶瓷高效低损伤超声辅助多轴铣削的科学机理与工艺规律亟待进一步研究。本项目提出经激光预制微织构将工程陶瓷离散化的思路，基于理论分析与多学科建模仿真，结合试验研究，优化匹配关键工艺要素，实现高效低损伤超声辅助铣削。本项目拟探明激光参数对几类工程陶瓷材料预制微织构特征的影响规律；揭示离散化工程陶瓷超声辅助铣削裂纹萌生、扩展机理与控制策略，检测表征切屑形貌，建立离散化工程陶瓷超声辅助铣削的高频动态多物理场耦合模型，明确材料去除特性与表面创成机理；仿真预测与测量分析加工区域离散化后的材料去除率、切削力及切削温度的时变规律；探明关键工艺要素对加工表面完整性的影响规律，分析刀轴矢量与高频动态刀-工交互作用特性间的关系，进行机理驱动的多目标耦合工艺寻优，并进行加工应用，为工程陶瓷高效低损伤超声辅助铣削提供理论指导与技术支持。

本项目研究了氧化铝陶瓷激光制备微坑型微织构、氧化铝陶瓷和氮化硅陶瓷激光制备凹槽型微织构、氧化铝陶瓷和氮化硅陶瓷激光制备凹槽型微织构性能对比等内容，采用优选的工艺参数制备了井字形凹槽微织构阵列，并进行了检测表征；进行了超声工艺参数与磨粒运动特性和加工效果间的关系研究，研究了工程陶瓷微织构优化制备加工，进行了微尺度微纳米压痕建模仿真与试验研究，并分析了划痕材料行为研究，在试验研究基础上对离散化工程陶瓷材料旋转超声铣削进行了微尺度建模仿真机理研究，阐明了陶瓷材料在高频超高频载荷作用下物理层面的的行为模式和去除机理；针对硬脆材料离散化旋转超声加工，进行了宏观整体刀具复合运动有限元建模仿真，分析了不同类型微织构离散化工件后加工排屑特点和等效应力场变化规律；进行了微观磨粒单一/复合运动有限元建模仿真，对比分析了方形、球形、五边形磨粒与材料之间交互作用特性；进行了微织构优化激光加工，分析了激光复合超声加工机理与工艺规律，探讨了氧化铝陶瓷平面/离散化铣磨加工表面质量与刀具磨损，分析了裂纹萌生、扩展机理和工艺策略；分析了工艺因素交互作用，优选试验参数，进行了样件加工试验。