鋁合金材料具有高強度、質量輕及成形性佳等優良性質，已被廣泛應用於諸多產品。鋁合金材料之硬度、強度及伸長率等機械性質為輕量化的結構件採用時必須考量之要素。然而，機械性質會受到熱處理的多種可控因子影響，導致品質不穩。本研究以熱處理之固溶溫度、淬火溫度、人工時效溫度及人工時效時間做為A6066鋁合金進行時效硬化─T6之可控因子，採田口方法設計實驗，再結合灰關聯分析來探討多重品質特性問題，以求得整體最佳製程參數水準組合。同時，配合實際試驗對於期望提升鋁合金機械性質的結果加以驗證。研究結果顯示：最佳製程參數組合為固溶溫度「530°C」、淬火「室溫」、人工時效溫度「190°C」及人工時效時間「四小時」。經變異數分析得知，人工時效溫度為影響多重品質特性最重要之因子。最後，將驗證實驗結果與灰關聯度最高之實驗組數據比較，顯示硬度提升11.14%、垂直（T）方向的抗拉強度提升8.55%、平行（L）方向的抗拉強度提升9.45%。

Aluminum alloy is widely used in many products because of its high strength, lightweight, good formability, and other excellent properties. When using aluminum alloy in lightweight structures, mechanical properties such as hardness, strength, and elongation are considered. However, mechanical properties are subject to the impact of a variety of controllable factors including heat treatment, which leads to quality instability. This study applied A6066 aluminum alloy for age hardening with solution temperature, quenching temperature, artificial aging temperature, and artificial aging time using the T6 heat treatment for controlling these factors. This study adopted the Taguchi Method to design the experiments, and integrated with Grey Relational Analysis to discuss problems associated with multiple quality characteristics, in order to determine the overall optimal combination of manufacturing process parameters. This study was validated by actual experiments, and the expected results improved the mechanical properties of aluminum alloy. Research findings suggested that the optimal combination of manufacturing process parameters issolution temperature at 530 °C, quenching at room temperature, artificial aging temperature at 190 °C, and artificial aging time at 4 hours. The ANOVA (analysis of variance) indicated that the artificial aging temperature was the most important factor affecting the multiple quality characteristics. Finally, the comparison of the experimental results with the data of the experimental group of highest Grey Relational Grade indicated that the alloy hardness improved by 3.38%, the tensile strength in the vertical direction (T) improved by 8.79%, and the tensile strength in the parallel direction (L) improved by 10.73%.