磁流变弹性体砂轮的制备及其柔性抛光机理研究

Milling, grinding and others mechanical processing methods are generally used to process ultra precision parts and molds, but there are some machining marks and surface defects left by them, therefore, in order to improve the surface quality of the parts, the subsequent ultra precision polishing is likely to be not only required, but essential. However, the loose abrasive polishing or manual polishing often causes unstable removing, low machining efficiency problem. According to the above problem, this project is based on a Magnetorheological Elastomers (MREs) intelligent magnetic material, put forward a new kind of MREs grinding wheel and its polishing process with flexible controlled and abrasive distributed uniformly by magnetic field. Firstly, the theory and experimental study of MREs grinding wheel are developed based on its physical properties and magnetorheological effect, the coupled effects of magnetic field, temperature field and others field are mainly explored for grinding performance in the process of structured and curing, and grits uniform configuration mechanism is clarified, so the good performance of polishing wheel is obtained. Secondly, the law of the flexibility of grinding wheel influenced by magnetic field is revealed in the polishing process, and flexible polishing mechanism is carry out, the removal quantitative mathematical model of MREs grinding wheel is established, the polishing path and process parameters are optimized. At last, this project provides the new theory and the new method for high efficiency deterministic polishing technology, which is of important significance for promoting the technological progress of ultra precision parts and molds

超精密零件及模具经过铣削、磨削等机械加工后会残留加工痕迹和表面缺陷，因此需要后续的抛光工艺来进一步提高加工质量,然而采用游离磨粒抛光或人工抛光时普遍存在加工过程不易控制，加工去除率低等问题。针对上述问题，本项目基于磁流变弹性体智能磁控材料，提出了一种新型柔性磁场可控且磨粒均匀排布的磁流变弹性体砂轮及其抛光工艺。首先根据磁流变弹性体的磁流变效应和物理性能，开展磁流变弹性体砂轮制备理论及工艺研究，主要探索砂轮预结构化和固化过程中磁场、温度场等多场工艺参数对砂轮性能的耦合影响规律，阐明磨粒均匀排布机制，进而获得抛光性能优良的砂轮。其次，揭示抛光过程中磁场对砂轮柔性的影响规律，并开展柔性抛光机理研究，建立磁流变弹性体砂轮的定量去除模型，优化抛光路径和工艺参数。最后，本项目的实施将为高效率确定性抛光技术提供新原理和新方法，对于提高我国的超精密零件及模具制造水平具有现实意义。

随着机械及光电产品向小型化、轻便化发展，高精度、形状复杂的微小尺寸零件需求日益增长，给传统的超精密加工技术带来了巨大的挑战。目前，超精密加工技术存在加工效率低、自动化程度低、难以加工复杂面型和易造成工件表面或亚表面损伤等问题。针对上述情况，该项目以智能材料—磁流变弹性体为基体，研制新型磨具——磁流变弹性体砂轮并提出与之对应的磁控柔性抛光方法，实现了微小尺寸零件的高效、高精加工。主要内容包括：分析了超精密加工技术的市场需求和加工技术存在的问题，综述了目前柔性抛光技术的抛光机理和应用现状；研究了磁流变弹性体砂轮预结构化和固化过程中磁性颗粒的排布规律；进行了磁流变弹性体砂轮工艺试验及抛光去除机理研究；研制了一套磁流变弹性体砂轮的制备流程和一台适用于磁流变弹性砂轮的抛光装置。目前，项目组共发表论文8篇，其中SCI收录6篇，EI收录2篇，申请发明专利10项，获得发明专利授权4项，硕士论文1篇，正在培养硕士5名，研究成果达到了项目申请时的预期。本项目的研究成果对于智能材料的控制及应用、精密加工领域抛光质量和抛光效率的提高具有广泛的学术研究价值和工程应用前景。