Multi-objective Process Optimization of CO2 Laser + MIG Arc Hybrid Welding Aluminum Alloy 6061

[[abstract]]CO2雷射銲接鋁合金時，容易形成氣孔，如何有效改善銲接鋁合金產生氣孔的問題是極為重要的，而混合銲接中可以藉由MIG的熱源可以以改善材料的表面結構能增加材料吸收率，減少氣孔的生成和防止銲道龜裂的出現。雷射結合MIG之混合銲接，國外的學者，早已提出相關研究，想辦法克服銲接後缺陷，其最難克服的缺陷就是氣孔，本研究是利用製程夾具上的改良並加入二種設計的保護氣體，實驗結果顯示能夠有效地降低氣孔形成。CO2雷射搭配MIG電弧混合銲接後，利用各種銲接參數的組合方式，逐一探討氣孔的生成與數量的多寡，接著再應用田口主成份分析法、田口主成份結合模糊理論分析法、田口主成份結合反應曲面法，針對鋁合金6061銲道的抗拉強度、伸長率、銲道微硬度、孔隙度與彎曲強度等品質特性，推論出CO2雷射搭配MIG電弧混合銲接鋁合金6061多目標最佳化混合銲接參數組合，使各品質皆能獲得顯著改善。[[abstract]]Porosity is commonly found in welding of aluminum alloy with CO2 laser, so it’s crucial to find a solution to porosity reduction for aluminum alloy welding. By utilizing the heat source of MIG to ameliorate surface structure of materials, material absorbance enhancement, porosity reduction and bead cracking prevention can all be achieved. Hybrid welding combing laser and MIG has been proposed early abroad. The most intractable part of abating weld defects lies in porosity, and it is proved in this experiment that clamp perfection and addition of two shielding gases can effectively reduce porosity. After conducting hybrid welding of CO2 laser and MIG, various welding parameter combinations were considered to explore the genesis and amount of porosity, then in respect with the tensile strength, elongation, bead micro-hardness, porosity and bending strength, Taguchi-PCA, Fuzzy-based Taguchi-PCA and RSM (Response Surface Methodology)-based Taguchi-PCA were utilized to derive the multi-objective optimum parameter combination for hybrid welding of CO2 laser and MIG for aluminum alloy 6061 in order to enhance various properties significantly