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而成的新型高功能流体(MCF)，对形状复杂的微细管和毛细管内壁进行磁场控制抛光技术研究。在这种方法中，允许含有非磁性磨粒的MCF通过管子，并垂直于管子轴线施加旋转磁场。研究结果概括如下：(1)抛光特性：在无流体影响的情况下，研究了含有磨料颗粒的流体组成和磁场分布对管壁抛光的影响。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管壁上的压力分布，阐明了MCF抛光管壁的机理。(3)分步抛光和流动抛光的基本实验在抛光过程中，我们在不同粗糙度的内壁丙烯酸树脂管内填充了含有磨粒的MCF。阐明了划痕的位置和磨粒的运动方向是目前抛光方法抛光内管的重要因素，并证实了该抛光方法可以达到纳米量级的抛光效果。(4)利用隔膜泵流动微细管抛光系统进行了微管内壁抛光系统的试验。

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.