本研究為利用田口法探討放電加工鎳基合金Rene108,分別探討表面粗糙度及加工時間之最佳化參數組合。首先利用L8(27)直交表規劃實驗參數,將實驗所得單一品質之重要因子進行再L9(34)直交表第二階段之規劃實驗。選用的因子有電壓與極性、高壓輔助電流、低壓峰值電流、放電波幅、休止波寬、伺服間隙及伺服穩定等。探討表面粗糙度實驗之因子選用電壓與極性、低壓峰值電流、放電波幅及伺服穩定;探討加工時間實驗之因子選用高壓輔助電流、低壓峰值電流、放電波幅及伺服間隙,並經由各品質特性之信噪比來得最佳化組合參數。結果顯示影響表面粗糙度的最重要因子為低壓峰值電流及放電波幅,最佳參數組合所得的實驗結果為Ra1.297μm,與田口法之第一組最佳值Ra1.496μm比較時減少了0.199μm,有效地改善13%。影響加工時間的最重要因子為低壓峰值電流及放電波幅,最佳參數組合所得的實驗結果為79s,與田口法第六組最佳值83s比較減少了4s,並且有效地改善5%。本研究有助在放電加工鎳基合金時調整加工參數以節省加工時間或提高表面粗糙度品質。
The objective of this research study are to discuss and analyze the optimal parameters of surface roughness and processing time for Electrical Discharge Machining on Rene108 nickel-based alloy using the Taguchi method. First step is use L8(27) Orthogonal table find out the important factors then use L9(34) to verify the selected optimal parameters can make the result better. Orthogonal table. The input parameters voltage and polarity, high voltage current, low voltage peaks current, discharge amplitude, discharge pause amplitude, servo gap, servo stability as the experiment parameters. In the surface roughness confirmation factor experiment choose voltage and polarity, low voltage peaks current, discharge amplitude, servo stability to do the experiment. In the processing time confirmation factor experiment choose high voltage current, low voltage peaks current, discharge amplitude, servo gap to do the experiment. After that, The result shows the factors affect the surface roughness are ranked as low-voltage peaks current, discharge amplitude, and the optimal parameter experiment result on surface roughness is Ra1.297μm, less 0.199μm than the best of in Taguchi method NO.1 best value Ra1.496μm which is improved 13%; Then the order of the factors affect processing time are low-voltage peaks current, discharge amplitude , and optimal parameter experiment indicated that the result was 79s, which is improved 5% compared with the Taguchi method NO.6 best value of 83s and less than 4s . The experiment result of the present work reveals that the optimal parameter analysis using the Taguchi method and improved surface roughness or decrease processing time .