多维超声ELID复合高效镜面磨削纳米复相陶瓷表面层演化规律

Based on the efficient-mirror processing of hard-brittle materials such as ceramics, this project adopts a new multi-dimensional ultrasonic-aided ELID grinding technology which combines multidimensional ultrasonic vibration and ELID grinding to machine nanocomposite ceramics, and researches the machining mechanism and evolution law for the machined surface layer. Research on general design method of complex acoustic system for symmetric and asymmetric structure and establish system stability model and stability criterion under multi-dimensional ultrasonic-aided ELID grinding. The surface morphology and surface properties of different parameters was also investigated. The influences of various surface microstructure parameters on the surface friction, wear properties and lubrication properties were explored on the ground of surface texture effect on the tribological characteristics. The quantitative association laws and the corresponding prediction model between surface characterization parameters and processing parameters were established to satisfy the demands of preset surface morphology and surface properties, consequently achieved the controlled manufacture by selecting the appropriate processing parameters for oriented processing surface layer properties. Finally, the scientific essence of multi-dimensional ultrasonic-aided ELID grinding is revealed, which significantly prompts perfecting theory and application for efficient-mirror machining hard-brittle materials such as nanocomposite ceramics.

针对陶瓷等硬脆材料的高效镜面加工，基于多维超声振动与ELID超精密磨削相结合，提出一种新型的适用于纳米复相陶瓷材料多维超声ELID复合磨削技术，并对该方法下的表面层演化规律进行研究。研究非均匀介质和非对称结构复杂声学系统的通用设计方法，建立多维超声ELID复合磨削声学系统的稳定性模型及稳定性判据；研究不同参数下的表面形貌和表面性能，基于表面纹理对摩擦学特性参数的影响，探索不同表面微结构参数对表面摩擦磨损性能、润滑性能的影响规律，建立表面层表征参数与加工参数之间的定量关联规律和对应的预测模型，满足给定的表面形貌和表面层性能要求，实现选取合适的加工参数以获得面向加工表面层特性要求的可控制造。最终揭示多维超声ELID复合磨削技术的科学本质，对纳米复相陶瓷等硬脆材料的超精密加工理论的完善和实际应用起到促进作用。

针对陶瓷等硬脆材料的高效镜面加工，开展了多维超声ELID复合磨削表面层演化规律的研究。提出了适用于多维超声ELID复合磨削振动系统的设计方法，完成一维至三维试验装置的研制；基于单颗磨粒的运动特性，对三维超声ELID复合磨削的磨削力和表面质量进行分析和试验验证；对多维超声作用下混频效应对ELID磨削过程的电解作用机理进行分析，并定量评价了加工过程中砂轮的修整效果；针对超声ELID复合磨削过程中的空化效应，建立超声振动作用下扰动压力与扰动速度之间关系，获得空化效应对砂轮表面氧化膜及材料表面的影响规律；基于多维超声作用下ELID磨削表面创成机理，获得工艺参数对材料去除率、表面微观形貌、表面残余应力及组织演化的影响规律，并对加工后表面的摩擦特性进行分析；基于材料断裂力学提出了多维超声ELID磨削氧化膜损伤内应力模型，建立了机械力、热应力和内应力的理论模型，获得了力热耦合对氧化膜特性的影响规律；构建多维超声作用下工艺参数与材料去除率和表面粗糙度的预测模型，完成对加工过程材料的去除及表面质量的预测，实现对加工质量的定量评价，并对加工后亚表面的损伤进行分析。本项目的研究成果为多维超声ELID复合加工理论的完善及工程应用提供了参考，为硬脆材料高效镜面加工提供了一种新的工艺方法。