| 摘要: | 本論文主要以6022鋁合金(Al-0.6Mg-1.0Si)為實驗材料，探討不同製程條件對於6022鋁合金時效析出擧動之影響。 實驗分為兩部份，第一部份是藉由改變均質化參數、熱滾參數、退火參數、冷滾參數及固溶參數來模擬實際工業製程之固溶狀態，並配合微差掃描分析儀(DSC)、導電率量測及拉伸試驗，探討固溶處理對於組織的影響。第二部份是藉由改變預時效參數及階段式預時效參數來模擬實際工業製程之淬火狀態，並配合微差掃描分析儀(DSC)、導電率量測、拉伸試驗及穿透式電子顯微鏡(TEM)，探討6022鋁合金經過不同時間之40℃預備時效，對於後來高溫人工時效析出擧動之影響。尋找出最適合6022鋁合金之製程，使得6022鋁合金經過人工時效後，能得到較佳的析出強化效果。 由實驗結果得知，隨著均質化的溫度愈高，消除的晶出相愈多，且經由固溶處理後，回溶於基地的溶質原子也愈多，因此經由570℃×14h均質化處理可以獲得較好的固溶效果。為了施以短時間的固溶處理，即可獲得高濃度的過飽和固溶體，因此製程採用較高的固溶溫度(560℃)、490℃熱滾及不施以退火處理。 另一方面，6022鋁合金經過70℃×14h預時效、90℃×14h預時效或180℃×10minà70℃×1h階段式預時效後，無論施以多久的40℃預備時效，也不會生成G.P.Zones(Ⅰ)。所以不會因施以不同時間40℃預備時效，造成後來人工時效的強度不穩定。經過180℃×10minà70℃×1h階段式預時效時，基地內已經有針狀中間相β′的析出，再經過170℃×20min人工時效後，其強度還是最高。雖然其強度最高，但是預時效後的伸長率最低，表示烤漆前的成形性最差。對於汽車車體板材，在烤漆前有較佳的成形性與烤漆後具有較高烤漆硬化性的前提下。在製程上採取150℃×10minà70℃×1h階段式預時效，所得效果最佳。 This thesis primarily with AA6022 (Al-0.6Mg-1.0Si) for experiment material inquires into the different manufacturing process condition for AA6022 the effect of aluminum alloy aging precipitations. The experiment is divided into two parts. One simulates solution treatment of manufacturing process by transforming soaking parameter, hot rolling parameter, annealing parameter, cold rolling parameter, solution parameter. The other simulates cooling condition of manufacturing process by transforming pre-aging parameter. Also interlock the conductivity test, DSC, TEM, tensile test analyzes, seeking the optimum to match AA6022 the manufacturing process of aluminum alloys, make AA6022 through artificial aging can receive the good precipitation enhances the effect. The results indicate that AA6022 through 570℃soaking,490℃hot rolling, none-annealing, and 560℃solution can reduce constituent and acquire high concentration supersaturated solid solution by solid solution treatment. So they can promote more precipitation and increase strength. In the aspects of preaging, the matrix doesn’t promote G.P.Zones(Ⅰ) after 70℃×14h preaging, 90℃×14h preaging, or 180℃×10min+70℃×1h preaging, no matter how long AA6022 are treated at 40℃preaging. The matrix promotes the needle-like precipitates after 180℃×10min+70℃×1h preaging, and it has better strength. Although it has better strength, it has lower elongation. In other words, it has worse forming before baking. So AA6022 treated after 150℃×10min+70℃×1h preaging has better bake-hardening. |
