(1. 哈爾濱工業(yè)大學(xué)(威海) 山東省特種焊接技術(shù)重點實驗室，威海 264209；
2. 山東奧太電氣有限公司，濟(jì)南 250101；
3. 中車長春軌道客車股份有限公司，長春 130062)
摘 要: 采用激光填絲熔釬焊方法對5052鋁合金和H62黃銅異種金屬進(jìn)行對接試驗，填充材料為Zn-15%Al (質(zhì)量分?jǐn)?shù))藥芯焊絲，研究激光功率對接頭微觀組織、界面層結(jié)構(gòu)和力學(xué)性能的影響。結(jié)果表明：當(dāng)激光功率2100 W時，接頭因熱輸入過低而發(fā)生斷裂，激光功率在2400~3300 W范圍時，獲得了性能良好的接頭。黃銅側(cè)界面附近的過渡區(qū)有Al4.2Cu3.2Zn0.7( 相)和CuZn5化合物生成，界面層結(jié)構(gòu)可分為連續(xù)的CuZn相層和鋸齒狀的 相層，且隨著激光功率增大，CuZn界面層的厚度隨之增大。界面層附近出現(xiàn)顯微硬度最大值，焊縫區(qū)顯微硬度大于母材。隨著激光功率的增加，接頭的拉伸強度先增大后減小，當(dāng)激光功率為2700 W時，原始接頭和磨平余高后接頭的拉伸強度最大，分別為128 MPa和104 MPa。焊縫位置斷口為準(zhǔn)解理斷裂，界面層位置斷口為解理斷裂。
關(guān)鍵字: 激光熔釬焊；鋁/黃銅異種金屬；微觀組織；界面層結(jié)構(gòu)；力學(xué)性能
（1. Harbin Institute of Technology at Weihai, Shandong Provincial Key Laboratory of Special Welding Technology, Weihai 264209, China;
2. Shandong Aotai Electric Co., Ltd., Jinan 250101, China;
3. CRRC Changchun Railway Vehicles Co., Ltd., Changchun 130062, China）
Abstract:The laser welding-brazing process was developed for joining 5052 aluminum alloy and H62 brass in butt configuration with Zn-15%Al filler. The influences of laser power on the microstructure, interface layer structure and mechanical properties of the joints were studied. The results show that the joints breaks due to the low heat input with the laser power of 2100 W and acceptable joints are produced at the laser power of 2400-3300 W. The interfacial microstructure mainly consists of serrated layer Al4.2Cu3.2Zn0.7 adjacent to the weld seam and a straight continuous layer CuZn close to the brass substrate. The thickness of CuZn phase increases with the laser power increasing. The micro-hardness in the weld seam is greater than that in the base metal and the maximum value appears near the interface at the brass side. The tensile strength of joints increases first, and then decreases with the increase of the laser power, and the highest tensile strength of the original joints is 128 MPa and the joint of reinforcement-flattened is 104 MPa obtained at laser power of 2700 W. The fractography of weld seam is characterized by quasi-cleavage fracture, while the cleavage fracture is observed for the interfacial layer.
Key words: laser welding-brazing; Al/brass dissimilar metals; microstructure; interface structures; mechanical properties
