【摘要】：鋁鎂異種金屬的結(jié)合可以實現(xiàn)鋁和鎂的優(yōu)勢互補,因此鋁鎂焊接性能的研究和改善是其在應用和發(fā)展中亟待解決的問題。本課題主要開展了 6061鋁合金和AZ31B鎂合金的熔焊接工藝試驗及機理研究,探索鋁鎂焊接的成型工藝和力學性能特性,試圖獲得影響鋁鎂焊接接頭質(zhì)量的因素和機理。6061鋁合金和AZ31B鎂合金熔焊工藝試驗研究主要分為四部分,一是6061鋁合金和AZ31B鎂合金直接熔焊對接試驗、二是6061鋁合金和AZ31B鎂合金窄間隙和焊槍偏置鋁側(cè)的熔焊對接試驗、三是對6061鋁合金和AZ31B鎂合金焊接接頭進行退火熱處理試驗、四是6061鋁合金和AZ31B鎂合金加Zn過渡層MIG對接試驗。首先進行了 3mm厚的6061鋁合金和AZ31B鎂合金直接熔焊對接,當焊接電流為65-70A時可以得到有效的焊接接頭。其次進行了 3mm厚的6061鋁合金和AZ31B鎂合金留有空隙和焊槍偏置鋁側(cè)的熔焊對接試驗,得到的焊接接頭外觀成型較好。隨后對6061鋁合金和AZ31B鎂合金焊接接頭進行了退火熱處理的試驗研究,當退火溫度為350℃時,焊接接頭的性能得到了明顯改善,抗拉強度有所提升,硬度有所下降。最后進行了 6061鋁合金和AZ31B鎂合金加Zn過度層對接試驗,Zn的加入使得抗拉強度進一步提高,性能得到進一步改善。通過微觀組織、力學性能測試、SEM、EDS以及XRD等分析手段對不同的鋁鎂焊接接頭進行了分析發(fā)現(xiàn),Al_3Mg_2和Al_(12)Mg_(17)金屬間化合物的產(chǎn)生是影響焊接接頭質(zhì)量的主要原因,熱應力和柱狀晶對焊接接頭有消極影響。通過試驗發(fā)現(xiàn),窄間隙和焊槍偏置鋁側(cè)可以減少熱輸出從而控制金屬間化合物產(chǎn)生,退火可以減少熱應力和柱狀晶,加Zn過渡層可以抑制Al_3Mg_2和Al_(12)Mg_(17)金屬間化合物的生成。
[Abstract]:The combination of aluminum-magnesium dissimilar metals can realize the complementary advantages of aluminum and magnesium, so the research and improvement of the welding properties of aluminum-magnesium is an urgent problem to be solved in its application and development. The experiment and mechanism study of 6061 aluminum alloy and AZ31B magnesium alloy were carried out in this paper, and the forming process and mechanical properties of aluminum magnesium alloy welding were explored. This paper attempts to obtain the factors and mechanism that affect the quality of Al-Mg welding joint. The experimental research on the welding process of 6061 aluminum alloy and AZ31B magnesium alloy is divided into four parts. One is the direct welding butt welding test of 6061 aluminum alloy and AZ31B magnesium alloy. The second is the weld butt test of 6061 aluminum alloy and AZ31B magnesium alloy with narrow gap and bias aluminum side of welding torch, the third is annealing heat treatment test of 6061 aluminum alloy and AZ31B magnesium alloy welded joint, the fourth is 6061 aluminum alloy and AZ31B magnesium alloy plus Zn transition layer MIG docking test. First, direct welding of 6061 aluminum alloy with 3mm thickness and AZ31B magnesium alloy was carried out, and an effective welding joint was obtained when the welding current was 65-70A. Secondly, the welding butt tests of 6061 aluminum alloy with 3mm thickness and AZ31B magnesium alloy with gap and biased aluminum side of welding torch were carried out, and the appearance of the welded joint was better. Then the annealing heat treatment of 6061 aluminum alloy and AZ31B magnesium alloy welded joints was carried out. When the annealing temperature was 350 鈩，

本文編號：2271942