Study of new high-precision polishing system type for inner walls of microtubes having complex shapes by magnetic field control

本研究的目的是利用磁流体与磁流变液混合的新型高功能流体（MCF），通过磁场控制，研究具有复杂形状的微管和毛细管内壁的抛光技术。在该方法中，允许含有可研磨磨料颗粒的MCF通过管，并且垂直于管轴施加旋转磁场。主要研究结果如下：（1）抛光特性：研究了含磨粒流体的组成和磁场分布对无流体效应的内管壁抛光的影响。抛光特性受磨粒浓度、磨粒直径和铁粉浓度的影响。(2)抛光机理：通过观察磨粒的行为和测量内管壁的压力分布，阐明了MCF抛光内管壁的机理。在电节点之间的中点处和离中心轴最远的区域处形成的磁簇的径向力作用于磨粒以产生用于这种抛光的力。(3)阶梯式抛光和流动抛光的基础实验在抛光过程中，我们将含MCF的磨粒填充到不同粗糙度的丙烯酸树脂内管中。阐明了划痕的位置和磨粒的运动方向对本抛光方法抛光内管的重要性，并证实了本抛光方法可以达到纳米级的抛光。（4）抛光系统的试验通过隔膜泵使MCF流动，实验性地制成了微管内壁的抛光系统。

The purpose of this study is to research the polishing technology for inner walls of microtubes and capillaries having complex shapes by magnetic field control utilizing new high functional fluid (MCF) which is mixed magnetic fluid with MR fluid. In this method, an MCF containing nonmagnetic abrasive grains is allowed to pass through a tube, and a rotating magnetic field is applied perpendicular to the tube axis. The results of this study can be summarized as follows;(1) Characteristics of polishing:We investigated the effects of the composition of fluids containing abrasive grains and the magnetic field distribution on the polishing of the inner tube wall without the fluid effect. The polishing characteristics are affected by the concentration and the diameter of the abrasive grains, and the concentration of the iron powder.(2) Mechanism of polishing:The mechanism of inner tube wall polished by an MCF was clarified by observing the behavior of the abrasive grains and measuring the pressure distribution on the inner tube wall. The radial force of magnetic clusters formed at the midpoint between the elect : nodes and at the region furthest from the central axis acts on the abrasive grains to produce the force for this polishing.(3) Basic experiment for polishing inner wall with a step and polishing by flowingIn the polishing, we filled the MCF involved abrasive particles in the inner acrylic resin tubes with different roughness. We clarified that the position of the scratch and the motion direction of the abrasive particles are important on the finishing the inner tube by the present polishing method Moreover, it was confirmed this polishing method is able to polish up to nanometer order(4) Trial of polishing systemPolishing system for the inner walls of microtubes was made experimentally by flowing the MCF by a diaphragm pump.