- 學位論文
鋁合金板件溫成形與熱成形製程之基礎研究
Fundamental Study for Warm and Hot Forming Processes of Aluminum Alloy Sheets
摘要
近年來，隨節能減碳的國際趨勢，輕量化已是各大車廠的主要目標之一，鋁合金的比重僅為鋼材的1/3，經由時效硬化處理可得到高強度，使得許多鋼材逐漸被鋁合金所取代。鋁合金板件雖然擁有重量輕及耐腐蝕特性，但其成形性較傳統鋼板來得差，在沖壓成形中，除了容易產生破裂問題外，鋁合金甚低的E值，產生的回彈問題，使得尺寸精度上的變異難以克服。上述問題可由溫、熱成形製程解決，但其仍不普及，處於研究階段，有許多地方待探討，故本研究對此製程進行基礎研究，特別是介面摩擦、介面熱傳等介面特性研究。後續，希望將製程基礎研究的成果，應用於業界領域中。 由溫、熱成形製程的應用與研究價值，本研究選擇了AA6061與AA7075作為探討材料，經由單軸拉伸實驗，取得E值、材料曲線等材料參數，經由摩擦實驗、介面熱傳實驗，取得摩擦係數、介面熱傳係數等製程參數。並將上述實驗結果，用於建立鋁合金板件溫、熱成形製程CAE(Computer Aided Engineering)模擬分析技術。此技術對回彈問題、破裂問題、製程研究、製程優化與開發、業界模具設計，皆是有效的分析工具。另外，經由V彎基礎載具，探討製程中的回彈、破裂、成品機械性質問題，並由成形實驗結果，驗證CAE模擬分析與淬火因子分析的準確性。 由上述基礎製程研究的成果，探討製程問題與優化方向。考量成品機械性質的減損，一般溫成形成形溫度不超過250 ℃，但此狀況下對回彈、破裂問題的解決有限，需由其它方法解決上述問題，開發可克服成品機械性質減損問題的新製程，也是可行的方向。熱成形HFQ製程中，7000與2000系鋁合金的成形性問題、淬火速度需求的問題，也必須要克服。最後，對溫成形新製程- Aging Forming製程，進行了初步探討，此製程理論上可克服成品機械性質減損的問題，具有應用價值。
並列摘要
In recent years, with the international trend of energy saving and carbon reduction, lightweight has become one of the major goals of major car manufacturers. The proportion of aluminum alloy is only 1/3 of steel, high strength can be obtained through age hardening treatment, which makes many steel materials gradually replaced by aluminum alloy. Although aluminum alloy sheets have light weight and corrosion resistance, their formability is worse than traditional steel sheets. Through the process of stamping, except that aluminum alloy would crack easily, the low elastic modulus of aluminum alloy would make the springback problem, making variations of accuracy are difficult to overcome. The above problems can be solved by the warm and hot forming process, but it is still not popular and is in the research stage, there are many places to be discussed, so this study conducts basic research on this process, especially the interface characteristics such as interface friction and interface heat transfer. I hope to apply the results of basic research to the industry in the future. Based on the application and research value of the warm and hot forming process, this study selected AA6061 and AA7075 as the discussion materials. Through uniaxial tensile experiments, material parameters such as elastic modulus and material curve were obtained. Through friction experiments and interface heat transfer experiments, process parameters such as friction coefficient and heat transfer coefficient were obtained. The above experimental results are used to establish CAE(Computer Aided Engineering) simulation analysis technology for warm and hot forming process of aluminum alloy sheets. This technology is an effective analysis tool for springback problems, creak problems, process research, process optimization and development, and industry die design. In addition, through the V-bending, the problems of springback, crack, and mechanical properties of products are discussed, and the accuracy of CAE simulation analysis and quenching factor analysis is verified by the forming experiment results. Based on the results of the above basic process research, the process problems and optimization directions are discussed. Because of the reduction of mechanical properties of products, the general forming temperature does not exceed 250 ℃ in warm forming process, but the solution of the springback and crack problems in this situation is limited. It is necessary to solve the above problems by other methods. Developing a new process that can overcome the problem of mechanical properties of products, is also a feasible direction. In the hot forming HFQ process, the problems of formability of 7000 and 2000 series aluminum alloys and the need for quenching speed must also be overcome. Finally, a preliminary discussion on the new warm forming process-Aging Forming process, has been carried out. This process can theoretically overcome the problem of the mechanical properties of products and has application value.