(蘭州理工大學(xué) 省部共建有色金屬先進(jìn)加工與再利用國家重點(diǎn)實(shí)驗(yàn)室，蘭州 730050)
摘 要: 采用脈沖旁路耦合電弧MIG熔釬焊方法用ER4043鋁合金焊絲對5052鋁合金/鍍鋅鋼異種金屬進(jìn)行搭接焊，通過掃描電鏡、能譜儀、X射線衍射儀對所獲得的鋁/鋼連接界面進(jìn)行了分析與研究。結(jié)果表明：焊接接頭焊趾處是一個Zn的富集區(qū)，通過對該區(qū)域組織進(jìn)行分析發(fā)現(xiàn)，焊趾處的物相由靠近鋼側(cè)的Fe2Al5Zn0.4和焊縫中的Al-Zn固溶體組成。焊縫中的Si元素參與了界面處化合物層的反應(yīng)，并生成了Al8Fe2Si三元金屬間化合物，該三元金屬間化合物沿著焊縫側(cè)金屬間化合物FeAl3的邊緣分布。進(jìn)一步線掃描發(fā)現(xiàn)：Si元素在整個界面反應(yīng)層中有明顯富集現(xiàn)象。此外，在測試結(jié)果的基礎(chǔ)上對Fe-Al-Si三元金屬間化合物的生長過程進(jìn)行探討。
關(guān)鍵字: 鋁/鋼熔釬焊；擴(kuò)散；金屬間化合物；接頭界面
（State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,
Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:The dissimilar metals of 5052 aluminum alloy/galvanized steel were joined with lap joint by pulsed double electrode gas metal arc welding-brazing with ER4043 filler metal. The interfacial microstructures of the joints were analyzed by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffractometry. The results show that a zinc-rich zone locates at the weld toe，which is mainly composed of Al-Zn solid solution at the weld seam side and Fe2Al5Zn0.4 at the galvanized steel side. Si element in weld seam involves in metallurgy reaction of intermetallic compound formation and the Al8Fe2Si ternary phase is found, the phase Al8Fe2Si forms along FeAl3 side. The results of linear scanning indicate that Si atom obviously aggregates in the intermetallic compound layers. Further, the formation process of Fe-Al-Si ternary intermetallic compound was discussed on the basis of the test results.
Key words: aluminum/steel welding-brazing; diffusion; intermetallic compounds; interface microstructure
