基于热裂法微波切割加工工程陶瓷技术的研究

With advanced manufacturing technology development, ceramics has been widely applied on the aerospace, aircraft, automobile, light industry and chemical industry, etc. However, the ceramics machining technology obviously prevent its application. In this project, a novel ceramics cut method is proposed, which uses the microwave beam to cut the ceramic material based on microwave inducing thermal cracks. Combining into both theoretical and experimental study, the microwave beam focusing technology is deeply studied, which ensures the microwave beam energy concentrating on the machining region; the action mechanics between microwave and ceramic material will be researched, and then the energy transformation and translation laws are analyzed; for the ceramic bulk volume heated, the effects on micro-cracks generating and expending by the temperature of thermal action zone and stress distribution are deeply studied; the effects on the cutting edge quality by the cutting technique method and corresponding parameters are investigated using of microwave beam cutting experiments. Through the investigation on microwave beam cutting technology concerning with the corresponding basic theories and key technologies, the key technology problems will be solved, which provides the theoretical and technology in support of application of microwave beam on ceramics cut technique...This project developed has an important theoretical significance and engineering application values, which expresses in the development of high efficiency, low energy cost and environment-friendly advanced manufacturing and enhancement of engineering ceramics machining level.

针对陶瓷零件加工技术是制约其在航空航天、机械、汽车、轻工、化工等工业领域中应用的瓶颈问题，本项目提出基于热裂法的微波切割加工陶瓷材料新技术的研究。利用理论研究和实验研究相结合的方法，重点研究：微波束能量"聚焦"技术；微波与陶瓷材料相互作用机理和能量转化与传递的规律；体加热条件下，热影响区温度场、应力场对微裂纹生成和扩展的影响规律；工艺参数和工艺方法对切口质量影响规律。通过对微波切割加工技术中相关基础理论和关键技术的研究，解决微波切割陶瓷工艺中的关键技术问题，为微波切割加工陶瓷技术的工程应用提供理论和技术支持。.该项目的研究与开发对发展高效、低耗和环保的先进加工技术，提高工程陶瓷零件的加工制造水平具有重要理论意义和工程应用价值。

陶瓷材料具有优越的物理机械性能，在各个领域均有大量的应用需求。然而传统陶瓷加工方法存在成本高、效率低、切割质量差、能耗高和切屑污染等问题，这制约了陶瓷材料在航空航天、机械、汽车、轻工、化工等工业领域中更为广泛的应用。本课题开发出基于热裂法的微波切割加工陶瓷材料新技术，并对其中的关键科学问题进行了研究。首先建立了微波能量聚焦增强的理论模型，基于此理论模型，建立两种微波聚焦物理模型，实现了椭圆形分布的聚焦微波热源和圆柱形分布聚焦微波热源。研究发现两种热源在对称轴方向均具有高斯分布的特点，均可对玻璃和SiC陶瓷板在一定厚度内进行整体加热。其次建立了微波加热陶瓷材料的理论模型，通过仿真分析和实验分析发现，微波可对介电系数较高的SiC陶瓷进行快速加热，对Na-Ca玻璃可以进行正常加热，而对介电系数较低的Al2O3、ZrO2陶瓷则很难进行加热。然后建立了微波热裂切割陶瓷板材的理论模型，该理论模型充分考虑了微波热裂法切割不同于激光热裂法的微观机理，揭示了位错移动在裂纹扩展应力阈值判断的作用。基于该理论模型建立的微波切割陶瓷板材过程的温度场仿真模型和应力场仿真模型。研究发现，微波热裂法切割陶瓷板材的过程中，板材上下表面和内部同时被加热，在裂纹扩展前方有较长内部压应力区，裂纹尖端处为拉应力区，拉应力驱动裂纹发生扩展，较长内部压应力区保证了裂纹扩展较激光热裂法更稳定,从而获得更好的切割质量。最后对微波热裂切割加工SiC陶瓷板进行了工艺实验研究，研究发现，微波切割SiC过程中，表面没有热损伤，切割表面质量较好，具有较大的应用前景。