镁/钢激光-MIG熔钎焊接头微观组织分析及性能研究
|
摘要
在钢表面电镀20μm的纯铜,以AZ31B镁合金焊丝作为填充材料,采用激光-MIG熔钎焊连接AZ31B镁合金和Q235钢,研究不同参数下熔钎焊接头宏观形貌、微观组织及力学性能。结果表明:在合适的焊接参数下,激光-MIG熔钎焊能得到较好的焊缝表面成型。焊接速度为6 mm/s时,钢侧界面区有3～5μm的界面反应层,且为双层结构。通过EDS和XRD分析,钢侧反应层主要是Al Fe3、Al2Cu3化合物,靠反应层的焊缝区是α-Mg固溶体和Mg2Cu、Al CuMg化合物,焊缝中部为是α-Mg固溶体和Al12Mg17化合物。在最优焊接工艺下,抗拉强度最高,达到188.97 MPa。
20 μm pure copper was plated on steel surface, AZ31 B magnesium alloy welding wire was used as filler metal to join AZ31 B magnesium alloy and Q235 steel by laser-MIG welding-brazing. The macro-morphology, microstructure and mechanical properties of welded-brazed joint under different parameters were studied. The results show that good laser welded-brazed seam formation can be obtained under appropriate welding parameters. When the welding speed is 6 mm/s, the steel side interface area has 3-5 μm interface reaction layer which is double layer structure. Through EDS and XRD, the steel side reaction layer is mostly Al Fe3, Al2 Cu3 compounds, and the weld zone near the reaction layer is α-Mg solid solution and Mg2 Cu, Al CuMg compounds, and the center of the weld is α-Mg solid solution and Al12 Mg17. The tensile strength is up to188.97 MPa under the optimum welding process.
20 μm pure copper was plated on steel surface, AZ31 B magnesium alloy welding wire was used as filler metal to join AZ31 B magnesium alloy and Q235 steel by laser-MIG welding-brazing. The macro-morphology, microstructure and mechanical properties of welded-brazed joint under different parameters were studied. The results show that good laser welded-brazed seam formation can be obtained under appropriate welding parameters. When the welding speed is 6 mm/s, the steel side interface area has 3-5 μm interface reaction layer which is double layer structure. Through EDS and XRD, the steel side reaction layer is mostly Al Fe3, Al2 Cu3 compounds, and the weld zone near the reaction layer is α-Mg solid solution and Mg2 Cu, Al CuMg compounds, and the center of the weld is α-Mg solid solution and Al12 Mg17. The tensile strength is up to188.97 MPa under the optimum welding process.
引文
[1] Ghassemieh E. Materials in automotive application, state of the art and prospects[M]//New Trends and Developments in Automotive Industry. In Tech, 2010.
[2] Easton M, Gibson M, Beer A, et al. The application of magnesium alloys to the lightweighting of automotive structures[M]//Sustainable Automotive Technologies 2012, 2012:17-23.
[3]曹睿,朱海霞,王清,等.镁/钢异种金属CMT对接熔钎焊连接机理[J].焊接学报,2016,37(5):37-40.
[4] Pierre D, Viala J C, Peronnet M, et al. Interface reactions between mild steel and liquid Mg-Mn alloys[J]. Materials Science&Engineering A, 2003, 349(1/2):256-264.
[5]肖荣诗,吴世凯.激光-电弧复合焊接的研究进展[J].中国激光,2008,35(11):1680-1685.
[2] Easton M, Gibson M, Beer A, et al. The application of magnesium alloys to the lightweighting of automotive structures[M]//Sustainable Automotive Technologies 2012, 2012:17-23.
[3]曹睿,朱海霞,王清,等.镁/钢异种金属CMT对接熔钎焊连接机理[J].焊接学报,2016,37(5):37-40.
[4] Pierre D, Viala J C, Peronnet M, et al. Interface reactions between mild steel and liquid Mg-Mn alloys[J]. Materials Science&Engineering A, 2003, 349(1/2):256-264.
[5]肖荣诗,吴世凯.激光-电弧复合焊接的研究进展[J].中国激光,2008,35(11):1680-1685.