| 摘要: | 大面積放電加工因排渣路徑長，加工屑排除不易，容易造成放電集中，導致材料移除率降低，所以本論文主要以改善加工屑排除不易問題及提升材料移除率為研究方向。針對加工屑排除不易的問題，我們提出兩種輔助機制來幫助加工屑排除，一種為在加工液裡添加鋁粉，使加工間隙加大增加流動空間、加工屑變小使移動性更好，另一種則是在工件兩側增設磁鐵加速加工屑排出，另外我們再將這兩種輔助機制同時應用於放電加工作業，探討材料移除率是否有再進一步提升。 研究結果顯示，以較佳的參數進行放電加工時，無輔助機制加工後的工件表面會產生加工屑與碳渣累積現象，電極直徑30mm、40mm、55mm加工30min後的材料移除率分別為0.70g/min、0.69g/min、0.20g/min；在添加鋁粉輔助下材料移除率分別為0.82g/min、0.77g/min、0.72g/min，且工件表面已無加工屑與碳渣堆積；在磁場輔助下的材料移除率分別為0.96g/min、0.83g/min、0.70g/min，工件表面同樣無加工屑與碳渣堆積；在同時應用添加鋁粉與磁場輔助的加工後材料移除率則分別為1g/min、0.93g/min、0.76g/min，工件表面亦未發現加工屑與碳渣堆積。從材料移除率及表面狀態得知三種輔助機制都能改善加工屑排除不易問題及提升材料移除率，其中又以同時應用添加鋁粉與磁場輔助加工後的效果最佳。Due to EDM have low working speed defect,working debris weren’t easily flushed and also debris deposit between electrode and work. In order to solve this problem, We propose three solutions .First ,We add aluminum powder in the working fluid can increase the gap distance between the electrode and workpiece and wastes bits can become small quality .Second , Add the magnetic field on both sides of the workpiece, increasing processing speed of debris flow. Third, while increasing the magnetic field and adding aluminum powder in the EDM, to enhance the material removal rate. From the experiment results, The use of better methods of processing parameters and no improvement of the workpiece surface will have a processing chip accumulation phenomenon. 30min after processing, electrode diameter, 30mm, 40mm, 55mm material removal rates were 0.70g/min, 0.69g/min, 0.20g/min;The first Techniques experiment results, Add aluminum material removal rates were 0.82g/min, 0.77g/min, 0.72g/min, and the workpiece surface did not chip accumulation phenomenon; Magnetic field-assisted material removal rates were 0.96g/min, 0.83g/min, 0.70g/min, and the workpiece surface did not chip accumulation phenomenon; Add aluminum powder processed with the magnetic field-assisted material removal rates were 1g/min, 0.93g/min, 0.76g/min, and the workpiece surface did not chip accumulation phenomenon. Three kinds of improvements can make the process smooth chip flow and enhance the material removal rate. Add aluminum powder and add magnet while the best results after processing |
