PCD端铣刀高效精密铣削工程陶瓷工艺基础研究

Advanced engineering ceramics with high hardness, low density, and excellent performance of wear, high temperature and corrosion resistance, etc., have received critical applications in the aerospace, electronics, energy, automotive, biomedical and other fields. To meet the demand of precision machining of typical small parts with three-dimensional structure that made of engineering ceramics, it is proposed that to use micro milling technique with ultra-hard end mills. In this project, some important scientific questions, such as the effects of tool characteristic parameters and un-cut chip thickness controlling on the machining process, and mechanism of tool wear under the condition of brittle-ductile transition removal process of engineering ceramic will be studied. Based on this, physical simulation experiments, precision milling tests, and microscopic inspection and analysis of machined surface and cutting edge of the wore tool, will be carried out. The critical un-cut chip thickness of material has been detected by tests, the relationship of tool parameters, cutting thickness and critical un-cut chip thickness will have been understood, and used to as a basis for guiding the setting of machining parameters . The mechanism of machined surface formation in Precision milling of engineering ceramics has been revealed. The tool wear characteristics and mechanism also have been analyzed. Finally, cutting parameters selection principle based on a balance of the machined surface quality and machining efficiency and Evaluation Index of the wore tools will be established. The goal is to achieve stable precision milling process with machined surface roughness Ra of 0.1μm or less, to provide technical support for the precision machining of engineering ceramics.

先进工程陶瓷材料具有高硬度、低密度、耐磨损、耐高温、耐腐蚀等优良性能，在航空航天、电子、能源、汽车、生物医疗等领域得到重要应用。项目针对工程陶瓷典型微小零件三维结构精密加工的需求，提出应用超硬刀具进行工程陶瓷的精密铣削加工工艺研究。项目重点研究超硬刀具特征因素以及切削厚度控制对加工过程的影响规律，以及工程陶瓷的脆塑转变去除过程对刀具磨损的作用机制等影响工艺应用的科学问题；在此基础上，运用物理仿真试验、精密铣削试验、加工表面与刀具刃口微观分析等手段，通过测定材料临界切厚，探明刀具参数、切削厚度与材料临界切厚的应用关系，作为指导加工参数制定的依据；揭示工程陶瓷精密铣削表面形成机制以及脆塑转变环境下超硬刀具的磨损特征与机理；建立基于平衡加工质量与效率的加工参数选取原则以及刀具磨钝失效评价指标；实现稳定的精密铣削加工工艺（表面粗糙度Ra稳定在0.1μm以下），为工程陶瓷的精密加工提供技术支撑。

项目以氧化锆等工程陶瓷结构件的高效精密加工为背景，按计划针对PCD超硬刀具高效精密铣削氧化锆陶瓷过程中的铣削参数制定策略、已加工表面形成机制以及PCD超硬微铣刀的刀具磨损机理等问题进行了研究，项目完成情况与主要成果如下：（1）以硬脆材料延性域去除理论为基础，结合精密铣削尺度特征分析了精密铣削与常规铣削的区别，提出了以限制最大切削厚度为目标的精密铣削参数选取准则，为工程陶瓷高效精密铣削参数设置提供了依据，稳定实现了氧化锆陶瓷精密铣削，表面粗糙度低于Ra0.1μm。（2）通过对延性铣削表面材料的塑性侧流、周期性刀痕纹理等微观形貌特征、已加工表面的凹坑、裂纹以及崩边等表面质量缺陷的观察与分析，揭示了氧化锆陶瓷精密铣削已加工表面形成机制。（3）通过对PCD刀具延性域精密铣削工程陶瓷刀具磨损特征进行了观察与分析，提出了精密铣削时PCD刀具磨损的评价指标，揭示了的PCD刀具以金刚石颗粒脱落以及氧化锆粘结磨损为主的磨损机理。项目组发表学术期刊论文6篇，其中被SCI收录2篇、EI收录1篇。授权发明专利1项，实用新型专利1项，申请发明专利2项，培养硕士研究生3人；获地方科技创新创业领军人才项目1项。本项目的研究结果将为半导体、医疗、新能源等行业装备中陶瓷结构件的制备提供技术支撑。