Developing of abrasive flow machining with rotation motion
| Autor: | Hsuan-Liang Lin, 林宣良 |
|---|---|
| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 Abrasive flow machining (AFM) is a efficient method of surface polishing, In AFM process, two cylinders are used to control the up and down motions of the abrasive medium to polish workpiece surface. Moreover, it can quickly remove recasting layers which made by wire electrical discharge machining. However, conventional AFM method has difficulty achieving uniform roughness of an axial distribution in circular holes polishing since one-way motion of abrasive media. Therefore, a study with a novel helical passageway is one of the solutions to reduce the surface roughness. The helical motion of abrasive medium in the polishing area exerts an additional tangential force along the tangential direction of the workpiece excepting the original axial force and the radial force. The tangential component can affect the performance of radial and axial surface roughness and uniformity. However, this method may exist a disadvantage in increasing working time due to additional resistance on flowing velocity. In the present work, a rotational mechanism to drive cutting forces on the workpiece surface is developed by modifying AFM set-up. To perform multiple flowing paths of an abrasive medium, whose flowing character can enhance polishing precision by increasing the abrasive area and axial sheared forces. In this investigation, two main schemes both simulation and experiment method are developed. Above all, numerical results simulated by CFD-ACE+ software indicate that the motion of rotational passageway significantly affected multiple directions when the abrasive medium in the channels would produce multiple flowing paths of velocity. It predicted to obtain the goal for the even surface of an axial distribution in circular holes polishing. In addition, the one factorial experiment and Taguchi reaction characteristics method were adopted to verify the optimal combination of design parameters and factors of a rotational mechanism. The experiment results demonstrate the critical parameters, which include the rotation speed, the colloid concentration ratios, abrasive number. Finally, after conducted a series of experiments, the results indicate that the rotational passageway is superior to circular passageway, in reducing roughness improvement rate (RIR) by roughly 88% compared with RIR 61% for the circular passageway. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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