本文關鍵詞：中強高導鋁合金線的制備與性能研究　出處：《鄭州大學》2017年碩士論文　論文類型：學位論文

  更多相關文章： 鋁合金導線 合金元素 性能 熱處理 加工工藝

【摘要】：Al-Mg-Si合金由于具有良好的力學性能、導電性、塑性成形性及耐腐蝕性而廣泛應用于遠距離、大跨越輸電線路中。為滿足輸電線路增容改造的需求,開發(fā)一種新型中強高導鋁合金導體材料,在保證合金強度的同時,進一步提高材料的導電性,并應用于制造中強全鋁合金絞線,具有較好的綜合優(yōu)勢。本文以架空裸導線用Al-Mg-Si合金導體材料為研究對象,調(diào)整Mg、Si、混合稀土RE和B元素進行合金化處理設計出合金成分,對比不同加工工藝下合金的組織及性能,得出優(yōu)化的Al-Mg-Si-RE-B合金成分,探討了優(yōu)化的Al-Mg-Si-RE-B合金的鑄態(tài)組織、稀土相及非平衡相組成等,研究了均勻化處理、不同加工工藝及時效對合金組織與性能的影響,制備出高性能的中強高導Al-Mg-Si-RE-B合金單絲。主要研究結(jié)果如下:(1)通過綜合對比四種設計的合金在不同T8態(tài)下的抗拉強度、導電率和伸長率,得出最優(yōu)的合金成分為Al-0.32Mg-0.42Si-0.2RE-0.08B,此時合金單絲的抗拉強度、導電率和伸長率可達到246.67MPa、60.12%IACS和6.9%。最優(yōu)合金鑄態(tài)時抗拉強度和導電率為105.0MPa和56.42%IACS。(2)最優(yōu)合金的鑄態(tài)組織中稀土元素在長條狀α(Al-Fe-Si)附近處富集,形成了不含F(xiàn)e元素的球狀Al-Si-(La/Ce)復雜物相。此外,稀土RE和B產(chǎn)生交互作用,形成了Al-B-(La/Ce)相。非平衡組織中存在大量的Al-Fe-Si三元共晶相,其中長條狀或魚鱗狀的α(Al-Fe-Si)相的存在較多。(3)不同均勻化處理下,隨著溫度(540℃、560℃、580℃)的升高或保溫時間(6h/7h/8h/9h)的增加,最優(yōu)合金的硬度呈下降趨勢,導電率呈上升趨勢,最后均趨于穩(wěn)定。對比最優(yōu)合金的顯微組織、導電率和硬度的變化,得到最佳均勻化處理工藝為570℃下保溫8h,導電率達到57.12%IACS。(4)Al-0.32Mg-0.42Si-0.2RE-0.08B合金單絲在150℃、170℃和190℃時效時,抗拉強度隨時效時間的增加呈先增加、后降低的變化規(guī)律。隨著時效溫度升高,鋁合金單絲強度達到峰值的時間越少;時效溫度越高,達到的峰值并不一定越高。Al-0.32Mg-0.42Si-0.2RE-0.08B合金單絲在150℃、170℃、190℃和210℃時效時,隨著時效時間的增加,導電率呈遞增的變化趨勢,最后趨于穩(wěn)定,但是導電率增加速率存在不同。時效時間相同時,溫度越高,鋁合金單絲的導電率越高。(5)綜合考慮導線的設計原則和時效溫度、時效時間等對合金單絲性能的影響規(guī)律,得出Al-0.32Mg-0.42Si-0.2RE-0.08B中強鋁合金單絲的合理時效工藝為190℃下保溫9h,其抗拉強度、導電率和伸長率分別為241.82MPa、60.24%IACS和6.2%。
[Abstract]:Al-Mg-Si alloy is widely used in long distance and long span transmission lines because of its good mechanical properties, electrical conductivity, plastic formability and corrosion resistance. A new type of medium and high conductance aluminum alloy conductor material is developed, which not only ensures the strength of the alloy, but also improves the electrical conductivity of the material, and is used in the manufacture of medium and strong all aluminum alloy strands. In this paper, the Al-Mg-Si alloy conductor material for the bare wire is studied, and the Mg-Si alloy is adjusted. The alloy composition was designed by alloying RE and B elements, and the optimized Al-Mg-Si-RE-B alloy composition was obtained by comparing the microstructure and properties of the alloy with different processing processes. The as-cast structure, rare earth phase and non-equilibrium phase composition of the optimized Al-Mg-Si-RE-B alloy were discussed. The effects of homogenization, different processing processes and aging on the microstructure and properties of the alloy were studied. The main results are as follows: (1) the tensile strength of the four designed alloys under different T8 states is compared by synthetically comparing the tensile strength of the four kinds of alloys. The optimum alloy composition is Al-0.32Mg-0.42Si-0.2RE-0.08B. the tensile strength of the single wire is obtained. The conductivity and elongation can reach 246.67 MPA. The tensile strength and electrical conductivity of the best cast alloy are 105.0 MPA and 56.42 IACS, respectively. The rare earth elements in the as-cast microstructure of the optimal alloy are enriched near the long stripe 偽 -Fe-Si. In addition, rare earth RE and B interact with each other. A large number of Al-Fe-Si ternary eutectic phases were formed in the nonequilibrium structure. Among them, the existence of 偽 -nAl-Fe-Si) phase in the shape of long strip or fish scale is much more than that of other phases. Under different homogenization treatment, with the temperature of 540 鈩，

本文編號：1356041