(1. 上海航天設(shè)備制造總廠，上海 200245；
2. 上海鍋爐廠有限公司，上海 200245)
摘 要: 采用BJ380A和ER4043鋁合金焊絲進(jìn)行7075/5A06異種鋁合金TIG焊對接試驗(yàn)，并對接頭的顯微組織和力學(xué)性能進(jìn)行分析。結(jié)果表明：焊縫無裂紋，但存在分散的氣孔；7075母材一側(cè)熱影響區(qū)晶粒長大較5A06母材一側(cè)的明顯，且采用BJ380A焊絲獲得的焊縫晶粒較采用ER4043焊絲獲得的焊縫晶粒粗大。采用兩種焊絲獲得的接頭抗拉強(qiáng)度均為220 MPa左右，約為5A06鋁合金母材的70%，且接頭均斷裂于焊縫處。顯微硬度測試時(shí)，7075母材一側(cè)熱影響區(qū)出現(xiàn)軟化現(xiàn)象，而5A06母材一側(cè)熱影響區(qū)出現(xiàn)硬化現(xiàn)象。另外，采用ER4043焊絲獲得的焊縫硬度大于采用BJ380A焊絲獲得的焊縫硬度。
關(guān)鍵字: 異種鋁合金；鎢極氬弧焊；顯微組織；抗拉強(qiáng)度；顯微硬度
（1. Shanghai Aerospace Equipments Manufacturer, Shanghai 200245, China;
2. Shanghai Boller Works Corporation Limited, Shanghai 200245, China）
Abstract:The butt joining of 7075 aluminum alloy to 5A06 aluminum alloy was conducted by TIG welding with BJ380A and ER4043 aluminum alloy filler wires, and the microstructure and mechanical properties of the joints were analyzed. The results show that the dispersive pores without cracks are observed in welds. The grain growth in the heat-affected zones (HAZ) near 7075 base metal is more obvious than that near 5A06 base metal (BM), and the grain is coarser in the weld made with BJ380A filler wire than that in the weld made with ER4043 filler wire. The tensile strength of joints is about 220MPa, 70% of that of the 5A06 aluminum alloy base metal, and the fracture occurs in the welds during tensile test. The microhardness results reveal that softening appears in the heat-affected zones near 7075 base metal, but hardening exists in the heat-affected zones near 5A06 base metal. Moreover, the microhardness in the weld made with ER4043 filler wire is higher than that in the weld made with BJ380A filler wire.
Key words: dissimilar aluminum alloy; TIG welding; microstructure; tensile strength; microhardness
