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

本研究的目的是研究利用磁流体与MR流体混合的新型高功能流体(MCF)通过磁场控制对具有复杂形状的微管和毛细管内壁进行抛光的技术。在该方法中，使含有非磁性磨粒的MCF穿过管，并垂直于管轴施加旋转磁场。本研究的结果可概括如下：(1)抛光特性：研究了含磨粒流体的成分和磁场分布对无流体作用下内管壁抛光的影响。抛光特性受磨粒浓度和直径以及铁粉浓度的影响。(2)抛光机理：通过观察磨粒的行为和测量内管壁上的压力分布，阐明了MCF抛光内管壁的机理。电极节点中点和距中心轴最远区域形成的磁团的径向力作用在磨粒上，产生抛光的力。(3)台阶抛光内壁和流动抛光的基础实验在抛光中，我们将含有MCF的磨粒填充在不同粗糙度的丙烯酸树脂内管中。我们阐明了划痕的位置和磨料颗粒的运动方向对于采用现有的抛光方法精加工内管非常重要。此外，还证实了这种抛光方法能够抛光到纳米级。(4)抛光系统的试验通过隔膜泵流动MCF，实验性地制作了用于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.