Abstract: MREAT, a new flexibility-controlled material used for grinding and polishing was developed to solve the problems of low machining efficiency, causing surface damages and difficulty in polishing complex curved surfaces in the ultra-precision machining processes. The influences of external magnetic fields on the microstructure and properties of MREAT were studied. A heat-magnet-force coupled device was designed to prepare anisotropic and isotropic MREATs with and without magnetic fields. Then the influences of external magnetic fields on the microstructure, compression mechanics properties and material removal properties of the new abrasive tool were analyzed. The results show that the magnetic field applied during the preparation processes causes the interior of the MREAT to appear as microscopic chains composed of carbonyl iron particles. After the preparation is complete, the compressive elastic modulus and polishing performance of the MREAT continue to increase with the increase of the magnetic fields. By analyzing the influences of the magnetic fields on the microstructure and performance of the MREAT, it is proved that the MREAT may realize the magnetically controlled flexible polishing processes.

Key words: magnetorheological elastomer abrasive tool(MREAT), magnetic abrasive tool, magnetic field-assisted compression molding, magnetorheological effect, ultra-precision machining

摘要： 针对现有超精密加工技术存在的加工效率低、易造成工件表面损伤和难以加工复杂曲面等问题，研制出一种柔性可控的新型研抛介质磁流变弹性体磨具，并研究了外加磁场对其微观结构和性能的影响规律。设计了一套热磁力耦合模压成形装置，在零磁场和外加磁场下制备出各向同性和各向异性磁流变弹性体磨具；分析了外加磁场对新型磨具微观结构、力学性能及材料去除性能的影响情况。结果表明：制备过程中施加的磁场会使磁流变弹性体磨具基体内部的羰基铁颗粒形成链状排列结构，制备完成后磁流变弹性体磨具的压缩弹性模量和研抛性能随着磁场的增强而不断提高，通过分析磁场对磁流变弹性体磨具的微观结构与性能的影响规律，证明了该磨具可实现磁控柔性研抛加工。

关键词: 磁流变弹性体磨具, 磁性磨具, 磁场辅助成形, 磁流变效应, 超精密加工