(蘭州理工大學(xué) 省部共建有色金屬先進(jìn)加工與再利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，蘭州 730050)
摘 要: 采用ER4047鋁硅焊絲對(duì)5052鋁合金與T2紫銅進(jìn)行脈沖旁路耦合電弧MIG熔釬焊，并對(duì)接頭顯微組織、物相成分及力學(xué)性能進(jìn)行分析。結(jié)果表明：通過控制焊接熱輸入可以獲得成形良好的鋁/銅熔釬焊搭接接頭。焊接接頭由鋁側(cè)熔合區(qū)、焊縫區(qū)和銅側(cè)類釬焊區(qū)組成，其中銅側(cè)類釬焊區(qū)可分為金屬間化合物層區(qū)和Al-Cu共晶區(qū)兩部分。焊縫區(qū)組織為珊瑚狀A(yù)l-Cu共晶體均勻分布在α(Al)固溶體中；銅側(cè)金屬間化合物層主要由條塊狀A(yù)l2Cu組成。隨著焊接熱輸入的增大，金屬間化合物層的厚度在增大，而接頭的抗拉強(qiáng)度先增大后減小；當(dāng)熔化的焊絲及鋁母材在銅母材上潤(rùn)濕良好并且焊縫與銅母材之間金屬間化合物的厚度較小時(shí)，接頭抗拉強(qiáng)度達(dá)到最大值，為167.7 MPa。
關(guān)鍵字: 鋁/銅異種金屬；熱輸入；顯微組織；金屬間化合物；力學(xué)性能
（State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:5052 aluminum alloy and T2 copper dissimilar metals were welded using 4047 AlSi12 wire by pulsed DE-MIG welding-brazing. The microstructure, elements composition and mechanical properties of joint were studied. The results show that it is feasible to obtain a favorable welding-brazing joint of Al-Cu by controlling the welding heat input. The welding joint is composed of fusion zone of the aluminum side, the weld zone and brazing zone of the copper side which is divided into two parts, Al-Cu eutectic zone and Al-Cu IMC layer zone. The microstructure of the weld zone is coral Al-Cu eutectic distributed in α(Al) solid solution, and IMC layer of Cu side mainly consists of strip Al2Cu. The tensile strength of joint firstly increases, and then decreases with the increase of welding heat input. When the wettability of wire and aluminum on the copper is good, and the thickness of IMC layer between the welding seam and the Cu base metal is relatively small, the tensile strength of joint can reach up to 167.7 MPa.
Key words: Al/Cu dissimilar metal; heat input; microstructure; intermetallic compound; mechanical property
