主成份田口法於A6061之預時效製程最佳化研究

A6061-T6 Optimization Using the Taguchi-PCA Method

鋁合金具有比強度高（密度與強度比值）、耐腐蝕與易回收等特性，對於講求節約能源、注重環保的現代，其用途愈來愈廣。由於，熱處理型鋁合金必須藉由熱處理技術以穩定品質。然而，熱處理製程會受到固溶處理、淬火及人工時效等多重因子之影響，造成其品質不穩定和成本高居不下。因此，將以時效熱處理前，利用不同水淬溫度之條件，評估使第二相粒子-Mg2Si先行孕核的預時效可行性，以利節省後續時效處理時間，俾能降低熱處理成本且提昇材料性能的品質。本研究即對於A6061-T6熱處理製程以田口方法進行參數最佳化設計。首先，進行初步的田口實驗，針對單一品質特性進行最佳化參數設計，再與主成份分析方法結合，將多重品質特性值轉換為單一性能指標，即為最佳整合性解。檢測的機械性質為硬度、抗拉強度與伸長率。當確認實驗與單一品質特性最佳值比較時，檢測結果發現：沿滾軋（T方向）的抗拉強度增加0.2％，伸長率改善1.1％，改善結果並不顯著。在多重品質特性指標變異數分析與因子分析研究結果顯示，人工時效溫度對製程具有最大的影響力，人工時效從8小時降為4小時，縮短製程時間。其驗證結果也令人滿意且可達節省實驗成本效果。

Aluminum alloys are used widely in energy conservation and environmental protection because they are strong, corrosion-resistant, and resilient. For manufacturing heat-treated aluminum alloys, stable heat treatment technologies are required, but heat treatment processes can be destabilized by factors such as solution treatment, quenching, and artificial aging. In this study, the Taguchi method was applied to design optimal parameters for the A6061-T6 heat treatment process. First, preliminary Taguchi experiments were conducted to design optimal parameters for single performance characteristics. Principal component analysis method was then used to convert the values of multiple performance characteristics into a single performance index, which was the optimal integrated solution. Confirmation experiments and optimized values of single performance characteristic were compared, and mechanical properties including hardness, tensile strength, and elongation were tested. The results of testing demonstrated that tensile strength along the rolling (T) direction was increased by 0.2%, and the elongation rate decreased by 1.1%. Indicator variance analysis of the multiple performance characteristics index and the results of factor analysis suggested that the manufacturing process was affected primarily by artificial aging temperatures. The results of validation tests were satisfactory and lowered experimental costs effectively