(哈爾濱工業(yè)大學 現(xiàn)代焊接生產(chǎn)技術(shù)國家重點實驗室, 哈爾濱 150001)
摘 要: 以CO2激光為熱源，以AlSi 12焊絲為填充材料，對Ti-6Al-4V鈦合金和5056鋁合金異種材料激光熔釬焊進行研究，采用SEM、EDS、XRD和金相顯微鏡分析接頭的微觀結(jié)構(gòu)特征，通過拉伸實驗評定接頭的力學性能。研究結(jié)果表明：所得接頭具有熔焊和釬焊雙重性質(zhì)，即鋁母材局部熔化，為熔化焊，而鈦母材與焊縫金屬之間存在金屬間化合物層釬焊界面；釬焊界面上部的金屬間化合物層組成復雜，可分為2層，即呈針狀或芽狀的Ti-Al-Si系金屬間化合物層和以Ti-Al系金屬間化合物為主的連續(xù)層；釬焊界面下部的金屬間化合物層較薄；拉伸試樣斷裂傾向于發(fā)生在緊鄰釬焊界面的焊縫上，平均抗拉強度為298.5 MPa。
關(guān)鍵字: 鈦合金；鋁合金；激光熔釬焊；金屬間化合物；接頭強度
Al/Ti dissimilar alloys
（State Key Laboratory of Advanced Welding Production Technology,
Harbin Institute of Technology, Harbin 150001, China）
Abstract:Laser welding-brazing (LWB) of Ti-6Al-4V and 5056Al was conducted using AlSi 12 filler metal. The microstructure characteristics of LWB Al/Ti joints were analyzed by SEM, EDS, XRD and optical microscopy. The joint strength was measured via tensile test. The results show that the joint has dual characteristics and can be divided into a welding part on the aluminium side and a brazing part on the titanium side. An intermetallic compound layer forms at the brazing interface between mixed seam metal and titanium. The intermetallic compound layer at interfacial top includes an acicular Ti-Al-Si intermetallic layer and a continuous Ti-Al intermetallic layer near titanium alloy. The intermetallic compound layer at interfacial bottom is thin and different from that at top. The average tensile strength of joints is 298.5 MPa. Fracture is prone to occur in the seam metal nearby brazing interface.
Key words: titanium alloy; aluminum alloy; laser welding-brazing; intermetallic compound; joint strength
