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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/2113

    Title: 材料製程對汽車車體用鋁合金彎曲加工特性之影響研究;The bending investigation of aluminum using in the car body sheet
    Authors: 張永政;Yang-Cheng Chang
    Contributors: 機械工程研究所
    Keywords: DSC;時效;製程;Al-Mg-Si;鋁合金;彎曲;Process;Al-Mg-Si;aging;Aluminum;DSC;bending
    Date: 2002-06-28
    Issue Date: 2009-09-21 11:38:39 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 本文針對6000系(Al-Mg-Si)鋁合金之彎曲狀況為研究目標,主要為探討影響彎曲試驗結果的各種可能因素。合金材料主要選擇以AA6022、AA6061、AA6N01及AA6063為研究對象,其中又分為三個方向來研究: 首先,AA6022滾壓材料於室溫時效下的彎曲狀況,其中改變均質化處理溫度、熱滾壓溫度、冷滾壓之加工量、固溶處理溫度、淬火速率、階段淬火溫度及自然時效時間的影響。實驗中配合微差掃描熱分析(DSC)、拉伸試驗機、光學顯微鏡(OM)及穿透式電子顯微鏡(TEM),用來比較影響影響彎曲試驗結果的可能因素。 其次,探討AA6061、AA6N01、AA6063擠型材之擠出時預時效溫度的影響。探討預時效溫度與時間的不同下,其晶內析出狀況對於烤漆時效後彎曲狀況的影響。 最後,對於AA6N01與AA6063擠型材擠出後之冷卻速率的改變、過渡元素Cr與Zr的添加及不同烤漆時效處理下,討論微結構與再結晶晶粒大小對彎曲性質的影響。 由實驗結果可知,AA6022分別以均質化溫度530℃×14小時,經480℃熱滾壓再施以冷加工量70﹪,選擇520℃固溶處理淬水後,使其晶內的析出較少且再結晶晶粒也較小,故彎曲狀況較佳。 而對於擠型材AA6061、AA6N01與AA6063而言,材料擠出後宜置於溫度40℃以避免G.P.Zones(I)的生成,如此使烤漆後有一定的強度,同時彎曲效果也可被接受。 另外,對於擠出成型後的淬火速率,宜選擇自然冷卻為佳。其中添加Cr與Zr所產生的分散相,抑制了再結晶成長而改善了彎曲狀況。最後選擇高溫175℃以1小時內之烤漆時效,如此可同時兼顧到析出強度與彎曲結果。 Aluminum-based Al-Mg-Si ternary alloys are must wisely used in applications. However, it should easily be form for makers and safety be used for users. First, we choose the different making process of AA6022 and observe the bending test results. For example the different soaking temperature, the different hot rolling temperature, the different cold rolling reduction ratio, the different solid solution temperature, the different quench rates, the different step quench temperature and the different natural aging time. The analysis styles were by using differential scanning calorimetry (DSC)and by tensile tests, and confirmed by structure observation using transmission electron microscope(TEM) and optical microscopy(OM). The results indicate that the small grain size and less precipitation aid nice bending status. So, the best experiment process of AA6022 are soaking at 530℃for 14hrs,hot rolling at 480℃,with cold rolling reduction ratio at 70%,quenching into water at room temperature ,then bending formed as quickly as possible. Second, the precipitation behaviors of AA6061, AA6063 and AA6N01 during Pre-aging and age-hardening after artificial aging were analyzed by using DSC, TEM, bending tests ,tensile tests and measuring the resistivity. The results indicate that pre-aging at 20℃with the low strength but bad bending status. For tensile tests results, the precipitation of GP Zone(I) form easily at 20℃ ,arrest the GP Zone(II) form during artificial aging . For bending tests ,however, the grain boundary precipitation particles were larger at pre-aging temperature 20℃ than at 0℃and 10℃.Because the large grain boundary particles are easily become the break point. Final, discuss the extrusion material of AA6063 and AA6N01 with quenching by different styles:water quenching, air quenching and natural quenching. Besides , discuss the Cr and Zr bearing in AA6063 and AA6N01,that form dispersoid Al18Cr2Mg3 and Al3Zr can avoid the grain grow when the recrystallization happened. The results indicate that natural quenching style will have well bending status because the less GP Zone (II) advent during artificial aging. Allowedly the strength of material quenching by natural cold is not well to be accepted. As regards Cr and Zr bearing in AA6063 and AA6N01,they widely improver the bending status.
    Appears in Collections:[機械工程研究所] 博碩士論文

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