| 摘要: |
| 对1.2 mm厚镀锌钢板和1.15 mm厚6016铝合金平板试件进行了加入中间夹层铅的激光搭接焊试验,通过调整焊接工艺参数获得最佳焊接成形,利用卧式金相显微镜、扫描电镜、X射线衍射、微机控制电子万能试验机等手段研究了焊接接头各区域的金相组织、断口形貌、主要物相与接头力学性能.结果表明,在钢/铝激光焊中添加中间夹层铅,焊接接头的平均抗拉强度和断后伸长率分别为68.51 MPa和2.37%,与没有加铅夹层相比,抗拉强度和断后伸长率明显提高;夹层铅的加入,改变了钢/铝界面的元素分布、物相组成及微观组织形态,焊接接头过渡区域Fe,Al,Zn,Mg,Pb元素的混合区宽度较大,除生成Fe-Al,Mg-Zn脆性金属间化合物外,产生了新的金属间化合物Mg2Pb,改善了焊缝金属的力学性能. |
| 关键词: 激光焊接 异种金属 金属间化合物 微观组织 |
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| 基金项目:国家863高技术研究发展计划资助项目(2007AA042006);国家自然科学基金资助项目(50805045);湖南大学汽车车身先进设计制造国家重点实验室自主课题资助项目(71075003) |
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| Laser lap welding of zinc-coated steel and 6016 aluminum alloy with Pb interlayer |
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PENG Li, ZHOU Dianwu, WU Ping, ZHANG Yi, CHEN Genyu
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State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China
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| Abstract: |
| The laser lap welding experiment with the Pb interlayer was carried out based on the DC56D + ZF galvanized steel of 1.2 mm and the 6016 aluminum alloy of 1.15 mm. The best appearance of welding were obtained by adjusting the welding parameters. By using optical microscopy, scanning electron microscopy, X-ray diffraction and the tensile test, mechanical properties of joints, fracture morphology and the main phase of the welded joint regional was studied. The results showed that when Pb interlayer was added in steel/aluminum, the average tensile strength and elongation of the steel/aluminum laser welding joints were 68.51 MPa and 2.37% respectively. Compared with that without Pb interlayer, the strength and alongation were improved significantly. The element distribution, phase composition and microstructure of the steel/aluminum interface were changed by the addtion of Pb interlayer. In the transition region of steel/aluminum joints, Fe, Al, Zn, Mg, Pb elements of the mixing zone width was larger, and a new ductile intermetallic compounds-Mg2Pb was produced, which could improve the mechanical properties of weld metal. |
| Key words: laser welding dissimilar metal intermetallic compounds microstructure |
