【正文】 以及濃縮鈾的離心分離筒、機(jī)械手、加速器、熱核反應(yīng)超真空裝置等。如6063，6064鍛鋁通過陽極氧化處理可在表面形成一層透明的氧化膜，并可著上各種顏色。2 鋁及鋁合金的分類鋁合金按加工方法可以分為形變鋁合金和鑄造鋁合金。這類合金具有優(yōu)良的鑄造工藝性和氣密性，中等強(qiáng)度，適合在常溫下使用，可生產(chǎn)形狀復(fù)雜的鑄件，應(yīng)用很普遍。(5)AlZn系合金。中國民航總局[3]從鋁合金硬度和導(dǎo)電率的測試及統(tǒng)計分析入手，測定2024鋁合金在不同時效溫度下，導(dǎo)電率和硬度基本達(dá)到穩(wěn)定狀態(tài)的時間，從而確定了一種新的時效制度來代替自然時效處理。在隨后的燒結(jié)或退火處理中，可析出大量細(xì)小的彌散的金屬間化合物，這些彌散析出相在高溫下非常穩(wěn)定，使合金具有較高的耐熱性能，目前己用該工藝生產(chǎn)了AlFe, AlTi等系列的新型耐熱鋁合金[11]。綜上所述，對變形鋁合金的研究主要在以下幾個方面:(1)采用優(yōu)化的熱加工和熱處理工藝，在合金組織中獲得盡可能多的細(xì)小第二相，以提高合金的室溫和高溫強(qiáng)度。金屬變形時產(chǎn)生的位錯不均勻分布, 先是較紛亂地成群糾纏, 形成位錯纏結(jié), 隨變形量增大和變形溫度升高, 由散亂分布位錯纏結(jié)轉(zhuǎn)變?yōu)榘麪顏喗Y(jié)構(gòu)組織, 這時變形晶粒由許多稱為“ 胞” 的小單元組成；高密度位錯纏結(jié)集中在胞周圍形成包壁, 胞內(nèi)則位錯密度甚低。所有可溶性合金化組元甚至雜質(zhì)都能產(chǎn)生固溶強(qiáng)化。其中, 二類質(zhì)點(diǎn)產(chǎn)生彌散強(qiáng)化, 三類質(zhì)點(diǎn)產(chǎn)生沉淀強(qiáng)化, 一類質(zhì)點(diǎn)中的難溶相產(chǎn)生的強(qiáng)化就稱為異相強(qiáng)化。為了進(jìn)一步提高鋁合金的強(qiáng)度，通常在零件成形后進(jìn)行熱處理。 （3）完全退火：又稱成品退火，是在較高溫度下，保溫一定時間，以獲得完全再結(jié)晶狀態(tài)下的軟化組織，具有最好的塑性和較低的強(qiáng)度。人工時效可分為欠時效和過時效。另外，杯突值m和1800彎曲半徑(0 t)都是鋼的最大。6000系合金中，6009和6016具有非常相似的機(jī)械機(jī)械性能，T4態(tài)的屈服強(qiáng)度低，因此具有優(yōu)良的成形性能，但是油漆烘烤的強(qiáng)度較低，約為180MPa。最近Edwards等人找到了在70℃時效的過程中，Si原子叢聚區(qū)、Mg原子叢聚區(qū)、Mg原子和Si原子叢聚區(qū)出現(xiàn)的直接證據(jù)。Cu在AlMgSi合金中的作用在近幾年也成為研究的熱點(diǎn)，研究表明，AlMgSi合金中加入銅，相形核更為容易，相密度增加，使合金時效強(qiáng)化能力提高，同時CuAl2和CuMgAl2也參與時效硬化作用，使合金的強(qiáng)度更高，但是當(dāng)Cu含量過高時，則會降低合金的抗蝕性。自然時效使人工時效后合金的強(qiáng)度、硬度下降?？棙?gòu)影響再結(jié)晶板材的塑性各向異性。在520540℃固溶處理時，含Mn的第二相粒子能抑制晶粒長大。而立方再結(jié)晶織構(gòu)一般認(rèn)為能提高板材的成形性能。所以本文主要探討預(yù)時效對鋁合金的組織和力學(xué)性能的影響。研究熱處理工藝對鋁合金板材組織和性能的影響規(guī)律，從而擴(kuò)大鋁合金板材應(yīng)用范圍是具備重要工程價值的研究課題。（2）從延伸率的對比可以發(fā)現(xiàn)，未經(jīng)熱處理的試樣，延伸率明顯偏低，很難滿足接下來的沖壓工藝的要求。n值小的材料易于產(chǎn)生裂紋，零件的厚度分布不均勻表面粗糙。綜上所述，熱處理后的鋁合金比未經(jīng)熱處理的鋁合金有更好的成形性。橫向豎向斜向試樣A試樣B試樣C試樣D試樣E（2）同時我們看到經(jīng)熱處理的四個試樣的強(qiáng)度相差不大，這說明在充分固溶后立即進(jìn)行預(yù)時效處理對強(qiáng)度的影響不是很大。通過對比可知E和C是低溫預(yù)時效的試樣，可能是較高溫度下的預(yù)時效處理的試樣產(chǎn)生的異相硬化小于固溶硬化下降的原因。因為最低固溶溫度500℃對于合金的再結(jié)晶來說已足夠高,且保溫時間也足夠長(約30min),板材再結(jié)晶過程已完成,另外,合金基體中殘留的合金相能阻礙再結(jié)晶后晶粒邊界遷移,所以固溶溫度在500~550℃之間變化對合金板材的再結(jié)晶晶粒大小及形狀影響不大。斷口掃描對比對可以看到，試樣A的斷口較為平整，試樣B、C、D、E則可以看到有明顯的韌窩,見圖47。 Tech, 1997,13(11): 905 910.[25] ZhuangL, de HaanR, Bottema J, Improvement in bake hardening response of Al2Si2Mg alloys[J]. Materi2als Science Forum, 2000, 331337: 13091314.[26] 關(guān)邵康,[J].機(jī)械工程材料, 2001,25(12): Shao kang, YAO Bo. Effects of preaging and prestrain on properties ofAl2Mg2Si alloys for automotive body sheets[J]. Materials for Mechanical Engineering,2001, 25(12): 1719.[27] Yamada K, Sato T, Kamio A. Preprecipitation and two step aging behavior of Al2Mg2Si alloys[ J]. Aluminum Alloys, 1998, 2: 709714.[28] Miao W F, Laughlin D E. Effects of Cu content and preaging on precipitation characteristics in aluminum alloy 6022[J]. Metallurgical and Materials TransactionsA, 2000, 31A(2): 361371.Ⅲ 翻譯部分英文原文DEVELOPMENT OF HIGH STRENGTH ALMGSI AA6061 ALLOY THROUGH COLD ROLLING AND AGEING . Niranjani, . Hari Kumar, V. Subramanya Sarma?Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai, 600036, IndiaAbstractUltrafine grained (ufg) and nanocrystalline (nc) materials are widely researched due to significant improvements in yield and fracture strength. However, achieving a reasonable ductility in these materials is still a challenge. Recent results have shown that the bination of high strength and ductility could be achieved in precipitation hardening alloys through severe plastic deformation followed by annealing/ ageing treatments. In the present work, the solutionised plates of an AlMgSi alloy (modified AA6061 alloy)were subjected to severe cold rolling at room and liquid nitrogen temperatures to a true strain ～. The rolled sheets were aged to induce precipitation. The equilibrium second phase distribution for the above alloy was calculated using CALPHAD. The rolled and aged samples were analysed using differential scanning calorimetry (DSC), Xray diffraction (XRD), transmission electron microscopy (TEM), hardness and tensile tests. The stored energy obtained from DSC measurements was found to be independent of the rolling temperature. The volume fraction of S {123} ﹤634﹥ orientation is predominant (～40%) in both the rolling conditions. The strength and ductility were simultaneously improved following ageing of the cryorolled (CR) and room temperature rolled (RT) samples. Transmission electron microscopy analysis revealed dislocation cell structures in the CR and RT conditions. Analysis of second phases revealed fine spherical Mn rich precipitates (most likely Al6Mn) following ageing.1 IntroductionAluminum alloys are widely used for fabricating high strength and light weight structures in automotive and aerospace applications. 6XXX alloys (AlMgSi based) have been studied extensively because of their high strength, good formability, weldability and corrosion resistance. In the last decade, severe plastic deformation (SPD) techniques such as equal channel angular pressing (ECAP), accumulative roll bonding (ARB), multiple pression and high pressure torsion (HPT) have been extensively researched to achieve grain refinement in polycrystalline materials [19]. The SPD processes however, require large amount of plastic deformation and special experimental procedures. Recently, deformation (rolling) at cryogenic (liquid nitrogen) temperature and low temperature annealing has also been shown to produce ultrafine grained (ufg) microstructures in Cu, Al, AA5083, AA2219 and Ni [1014]. Suppression of dynamic recovery during cryogenic deformation results in high defect density, which in turn leads to increased nucleation sites during annealing resulting in a finer grain structure [15]. However, achieving a reasonable ductility in these materials is still a challenge. Recent results [14,16–18] have shown that the bination of high strength and ductility could be achieved in precipitation hardening alloys through severe plastic deformation followed by annealing/ageing treatments. The precipitation sequence during ageing of Al alloys is plex and goes through many intermediate stages before the formation of equilibrium precipitates. In AlMgSi alloys, the sequence of precipitation from the supersaturated solid solution is generally believed to be zones→β〞→β′→β(Mg2Si, equilibrium). For a giv