陶瓷零件深小孔高效加工技术基础研究

Ceramic parts are more and more widely used in the fields of national defense and high technology. Micro-grinding technology offers the possibility to machine small ceramic parts of complex structure with significant technical advantage. Due to the fact that it was difficult to machine lots of high precision deep-holes efficiently in ceramic materials, the author in this paper firstly proposed how to solve the problems existing in micro-grinding process of deep-hole such as low processing efficiency, quick-wearing grinding wheel, and unstable precision and so on with rotary ultrasound-assisted micro-grinding technology, while systematically investigating the evolution mechanism and migration condition in relation to removal mode of brittle plastic and ceramic materials under the action of composite mechanical -ultrasound energy field; secondly explored the generating mechanism of rotary ultrasonic micro-grinding surface in ceramic materials, established the models of material removal and of grinding force, and analyzed the impact of ultrasonic vibration on grinding force and surface damage and other processing quality problems; and finally investigated the optimization of rotary ultrasonic micro-grinding process of micro-holes in ceramic materials, suggested the effective way to reduce and prevent the occurrence of edge chipping, and revealed the mapping relationship between ultrasonic vibration micro-grinding process conditions and processing efficiency and quality so as to provide theoretical basis and technical support for high efficient and low damage processing of such parts. The findings of this paper are valuable for expanding the application of hard and brittle materials with rotary ultrasonic micro-grinding processing technology in high-tech cutting-edge technology field.

陶瓷零件在国防和高技术领域的应用越来越广泛。采用微磨削技术可加工复杂结构的小型陶瓷零件，具有明显的技术优势。本课题针对陶瓷材料难以高效、高精度加工出所需众多深小孔问题，提出基于旋转超声辅助微磨削技术，解决微磨削制深小孔中存在的加工效率低、砂轮易磨损和精度难以保证等难题，系统地研究机械-超声复合能场作用下陶瓷材料脆塑性去除模式演变机制及迁移条件；研究陶瓷材料旋转超声微磨削表面创成机理，建立材料去除模型和磨削力模型，分析超声振动对磨削力和工件表面损伤等加工质量的影响；最后进行陶瓷材料旋转超声微磨削制深小孔优化工艺研究，提出减小和抑制深小孔出口崩边的有效方法，揭示超声振动微磨削工艺条件与加工效率和质量的映射关系，为实现此类零件的高效低损伤加工提供理论基础与工艺技术支撑，此研究结果对拓展旋转超声微磨削加工技术对硬脆材料在高新尖端技术领域的应用具有重要价值。

陶瓷零件在国防和高技术领域的应用越来越广泛。微晶云母陶瓷材料具有优良的物理性能，广泛应用于航空航天等领域。但由于在加工深小孔时，其深径比大，传统的处理方式所能实现的精度和质量都偏低。采用超声振动加工微晶云母陶瓷深小孔，解决深小孔加工中存在的效率低、砂轮易磨损和精度难以保证等难题。本项目研究了陶瓷材料去除机制，建立了磨削力的数学模型，分析了工艺参数对磨削力和加工表面质量的影响规律和影响程度。对磨粒的运动状态进行了分析，建立了理论去除率的模型并求出磨削力的数学模型，进行了深小孔的磨削实验;利用数字化图像处理技术和最小区域法对深小孔入孔表面圆度误差进行评定，对加工表面粗糙度信息进行了提取，分析了磨削参数对加工表面质量的影响;对超声振动加工中出口崩边的形成进行了分析，建立了出口崩边预测模型和铣磨加工出口崩边评价指标，总结了工艺参数对出口崩边指标的影响规律；研究发现超声振动刻划仿真计算得出普通刻划和超声振幅7μm时刻划的脆塑转变临界深度分别为1.529μm和2.848μm，切削力的最优工艺参数组合为(10000rpm，18mm/min，300w)。铣磨实验得出的出口崩边指标值和预测崩边指标值进行了对比，二者之间的平均误差为11.9%。本研究为实现此类零件的高效加工提供理论基础与工艺技术支撑，结果对拓展旋转超声辅助磨削加工技术对硬脆材料在高新尖端技术领域的应用具有重要价值。