本研究主要以田口方法作A390鋁合金(Al-17%Si-4.5%Cu-0.55%Mg)最佳化製程之應用
，探討製程參數對提升機械性質（抗拉強度、硬度及耐磨耗性）之影響。其中所考慮之
控制因素包括：磷調質量、固溶溫度、固溶時間、淬火液溫度、預備時效時間、時效溫
度及時效時間等七項。
實驗結果顯示，當磷調質量0.03%、固溶溫度480℃、固溶時間4小時、淬火液溫度55℃
、預備時效時間為24小時、時效溫度150℃及時效時間3小時，為A390鋁合金最佳之製程條
件，可同時提升抗拉強度、硬度及耐磨耗性等三種機械性質。為考慮到穩健性的設計時，
應將製程條件調整為固溶時間3小時及淬火液溫度75℃，其餘製程條件不變，可得到泛用
性及再現性高之抗拉強度值，但會稍降低硬度值及耐磨耗性。另，在A390鋁合金之最佳化
製程中，磷調質處理及固溶處理均為提升各項機械性質之主要參數，且磷調質量為0.03％
時，可減少人工時效之溫度及時間。
上述研究結果可提供工業界製造A390鋁合金時之參考，以及熱處理及相關工作人員，
應用田口方法致力於產品品質改善時之參考案例。

The purpose of this research was to obtain the optimum process of the A390 Aluminum Alloy by Taguchi Methods. Effects of processing parameters, including the modification quantity of phosphorous, the temperature and holding time of solution treatment, the temperature of quenching water, the holding time of preaging and the temperature and holding time of artificial aging, on the machinability (tensile strength, hardness and wear resistance) promotion of the A390 Aluminum Alloy were investigated in this study.
The results indicated that optimum parameters of modification were 0.03% of phosphorous, solution treatment at 480℃ for 4 hours, quenching at 55℃, preaging for 24 hours and artificial aging at 150℃ for 3 hours could increase the tensile strength, hardness and wear resistance of the A390 Aluminum Alloy together. For results of robust design, solution treatment at 480℃ for 3 hours and quenching at 75℃ were modified and the other parameters didn't change. The adjustment might acquire robust tensile strength, but depressed hardness and wear resistance slightly. Modification of phosphorous and solution treatment were the most important parameters of the optimum process of the A390 Aluminum Alloy. The temperature and holding time of artificial aging were reduced with the modification of 0.03% phosphorous.
The above results of experiment can give the manufacturers for reference and hope this research is valuable to those who devote the improvement of product with Taguchi Methods.