發(fā)布時間：2018-08-29 16:01

【摘要】：8000系列鋁合金導(dǎo)線憑借其高電導(dǎo)率高強度高抗蠕變性能，以及良好的經(jīng)濟價值，已受到越來越多的重視，在國內(nèi)外得到了廣泛的應(yīng)用，并且使用效果良好。本文在電纜用8076鋁合金導(dǎo)體基礎(chǔ)上，通過對合金成分設(shè)計、成形及熱處理工藝的研究，擬開發(fā)出一種微合金化的8076鋁合金導(dǎo)線。 為了進一步減小Fe元素對合金力學(xué)和導(dǎo)電性能的不利影響，研究了不同Mn元素加入量對合金組織與性能的影響；系統(tǒng)研究了拉拔工藝與合金線材組織和性能的關(guān)系，以期找出最佳的拉拔成形工藝；同時深入研究了熱處理工藝對合金線材組織和性能的影響，，確定合理的熱處理制度。Mn元素微合金化研究結(jié)果表明，Mn元素的加入，可以改變鑄態(tài)和擠壓態(tài)合金中Fe相的分布與形態(tài)，原來的針狀、大片狀、長條狀Fe相斷裂，變?yōu)殚g斷的短棒狀、粒狀、球狀等，減小對電導(dǎo)率和塑性的不利影響，大幅提高合金的抗拉強度；當(dāng)Mn元素加入量為0.05%時，獲得的線材綜合性能較好。拉拔工藝研究表明，在拉拔過程中，中間道次加入退火工藝后，獲得的線材導(dǎo)電性能普遍優(yōu)于直接冷拔的，其中在Φ3.5mm處經(jīng)過350℃中間退火后，最終拉拔線材綜合性能最優(yōu)，其電導(dǎo)率達到了61.32%IACS，抗拉強度為158.3MPa，伸長率為12.16%。退火工藝對線材性能影響研究表明，冷拔線材進行退火處理有利于改善其綜合性能，解決電學(xué)和力學(xué)性能的矛盾；退火溫度在160℃~400℃之間時，線材畸變的晶粒經(jīng)回復(fù)再結(jié)晶形核成新的等軸晶粒，并隨退火溫度的提高再結(jié)晶晶粒逐漸增多并長大，電導(dǎo)率呈先上升后下降的趨勢，當(dāng)退火工藝為：退火溫度330℃、保溫時間1.5h、隨爐冷卻，線材綜合性能最好，其電導(dǎo)率可達61.83%IACS，抗拉強度為108.6MPa，伸長率達21.86%，符合電纜導(dǎo)體用鋁合金線的國家標準；此外，線材的電導(dǎo)率與退火后的冷卻方式有關(guān)，其中隨爐冷卻得到的線材電導(dǎo)率要普遍高于空冷。時效熱處理工藝對導(dǎo)線組織與性能影響研究表明，時效熱處理使合金中析出了規(guī)則六方狀的(Al,Mg)相和塊狀(Al,Mg,Si,Fe)相；固溶溫度和時效工藝不同獲得的導(dǎo)線性能也不同，雙級時效較單級時效的電導(dǎo)率和伸長率有明顯提高；當(dāng)采用480℃/1h固溶+雙級時效處理后，線材的綜合性能達到最佳，電導(dǎo)率較冷拔態(tài)稍有提高，達到60.6%IACS，塑性大幅改善，伸長率達到了20.34%。
[Abstract]:With its high conductivity, high strength, high creep resistance and good economic value, 8000 series aluminum alloy conductor has been paid more and more attention, and has been widely used at home and abroad. On the basis of 8076 aluminum alloy conductor for cable, through the study of alloy composition design, forming and heat treatment process, a kind of 8076 aluminum alloy conductor with microalloying is developed. In order to further reduce the adverse effect of Fe on the mechanical and electrical properties of the alloy, the effects of different contents of Mn elements on the microstructure and properties of the alloy were studied, and the relationship between drawing process and the microstructure and properties of the alloy wire was systematically studied. At the same time, the effect of heat treatment on the microstructure and properties of alloy wire was studied, and the results of microalloying of element mn indicated that mn was added. The distribution and morphology of Fe phase in as-cast and extruded alloys can be changed. The original needle-shaped, large flake, long striped Fe phase breaks, and becomes discontinuous short rod, granular, spherical, etc., which reduces the adverse effect on conductivity and plasticity. The tensile strength of the alloy was greatly improved, and the comprehensive properties of the wire were better when the addition of Mn element was 0.05. The study of drawing process shows that the electrical conductivity of wire rod obtained by adding annealing process through intermediate pass is generally superior to that of direct cold drawing, and the comprehensive properties of wire drawn at 桅 3.5mm after intermediate annealing at 350 鈩

本文編號：2211698