DP590双相钢/6061铝合金激光熔钎焊工艺特性研究

摘要

采用1.2 mm厚双相冷轧钢板DP590、1.5 mm厚铝合金6061和药芯焊丝Zn-2％Al进行了铝/钢光纤激光熔钎焊接特性研究,分析了对接间隙和光束偏移量对接头显微组织和力学性能的影响.结果表明,不开坡口,采用间隙1 mm、光束零偏移,或采用间隙0.75 mm、光束向铝侧偏移小于1.2 mm,都可获得强度较高的接头,最大抗拉强度可达275.7 MPa,达到铝母材强度的88.37％,断裂于铝母材热影响区.激光光束偏向铝侧1.2 mm以内,获得的接头强度均在220 MPa以上.本实验中最佳接头界面化合物层厚度在1 μm以下.%Fiber laser welding-brazing of 1.2 mm-thick cold-rolled dual-phase steel DP590 and 1.5 mm-thick Al alloy 6061 with fluxcored wire Zn-2％Al was performed in butt configuration.Effects of welding parameters such as bridge gap and laser beam offset on the microstructure and properties of joints were investigated.The results indicated that the suitable process parameters were the bridge gap of 1mm with no offset of laser beam and bridge gap of 0.75 mm with offset toward Al alloy within 1.2 mm.The maximum tensile strength could reach 275.7 MPa,88.37％ of that of the base metal Al alloy.Fracture location was in heat affected zone of Al alloy in this case.The tensile strength could always surpass 220 MPa with offset toward Al alloy within 1.2 mm.And the thick of the intermetallic of best joints in this research was below 1 μm