- 學位論文
探討膠體磁力研磨加工法之加工機制
The Study of the Mechanism for Gel Magnetic Abrasive Finishing
摘要
磁性膠體磨料是以高分子膠體混合磁性顆粒與磨料，再搭配磁力研磨的加工方式可達到高效率的研磨方法。此種磁性膠體磨料不但製作簡單，且可回收重複使用，可大幅降低研磨成本。因此本研究使用磁性膠體磨料，對模具鋼SKD11進行表面的研拋，來探討磁性膠體磨料之拋光機制，且結合田口氏實驗法來建立膠體磁力研磨的最佳化參數，利用不同加工參數來觀察加工後表面粗糙度的改變，和各個加工參數研拋效應的影響，探討其拋光機制。且將此機制應用於不?袗?(SUS304)內管拋光，探討其研拋效應。 本研究先以ANSYS分析最佳之磁極形狀，再結合田口氏實驗法來建立膠體磁力研磨的最佳化參數，來觀察加工後試片的表面粗糙度，探討膠體磁力研磨之加工機制。其中使用水性玩具膠體對SKD11試片加工短短5分鐘後，表面粗糙度可由Ra0.621μm降至 Ra0.0275μm，表面粗糙度改善率高達到95.5%。SUS304管內壁拋光40分鐘，表面粗糙度可由Ra1.01μm降至 Ra0.029μm，驗證膠體磁力研磨確實具有優異的研拋效能。
並列摘要
Silicone gels mixing with steel grits and silicone carbons were abrasive media with permeance to obtain excellent polishing efficiency in the magnetic finishing with gel abrasive (MFGA). These abrasive media were not only easily produced but also recycled after machining, reducing the cost in MFGA; silicone gel play an important role in this study. However, there were no researches to discuss the mechanism in MFGA, decreasing the practicability in the magnetic finishing field. Therefore, different silicone gels were used to locate the abrasion behavior in this study and established mechanism of MFGA. Polishing efficiencies with or without silicone gels were identified to finish the cylindrical rod first in our study. In addition, Silicone gels are temperature dependent materials, so temperature in the working area was then to verify the relation between the circulation and efficiency. Moreover, concentrations were one of the important factors affecting the circulation of the abrasive media in the machining area; hence concentrations of silicone gels with different plasticity were to recognize the circulation of abrasive media in MFGA. Results showed that temperature of the abrasive media with low plasticity would exceed to 100oC in the working area and excellent circulation could find in the side of the abrasive media. Furthermore, Surface roughness of workpiece markedly reduced from 0.651 to 0.025μm Ra within 30 minutes. Regardless of silicone gels, fine circulating effects of abrasive media were effortlessly obtained in the working area when the abrasive media with low concentrations were used as bonding gel; additionally, surface roughness was easily reduced to 0.030μm Ra during the fine circulation.of the abrasive media. However, good polishing efficiency could locate in the high concentration of abrasive media if silicone gel with low plasticity was used as abrasive medium.