To explore the influence of wire feed rate (WFR) to speed ratio on arc stability, interfacial microstructure and mechanical properties, cold metal transfer (CMT) weld-brazed lap joints of aluminium alloy (AA5052) to dual-phase (DP780) steel were formed at a constant optimized heat input of 80 J/mm. Cyclic representation of recorded voltage and current showed that joining process was comparatively less stable at high WFR to speed combinations. At high WFR and higher speed combinations, greater spatial variations in intermetallic compound (IMC) layer thickness due to spilling of τ₅-Fe₂Al_7.4Si phase and higher porosity in the bead reduced the resistance to failure of the joints especially in the case of AlSi12 filler. Addition of Si successfully increased the wettability of the joints and also reduced the average thickness of the IMC layer at the interface. Formation of hard and brittle orthorhombic η-Fe₂Al₅ and monoclinic θ-FeAl₃ compounds was observed for pure Al filler whereas less brittle ternary Fe-Al-Si intermetallic phases formed with Si-enriched fillers. Three modes of failure, in the Al heat-affected zone (HAZ) (due to softening), bead (due to porosity) and interface (due to poor wettability/increased brittleness), were observed during shear tensile testing. The joints formed using AlSi5 filler at lower joining speed and low WFR combinations, i.e. high WFR/speed ratio, showed higher and consistent mechanical properties.

为了探究线速比（WFR）对电弧稳定性，界面微观结构和机械性能的影响，分别对铝合金（AA5052）与双相（DP780）钢的冷金属转移（CMT）焊接钎焊搭接接头进行了研究。在80 J / mm的恒定优化热量输入下形成。记录的电压和电流的循环表示表明，在高WFR与速度组合下，连接过程的稳定性相对较低。在高WFR和更高速度的组合，在金属间化合物（IMC）层厚度由于τ溢出更大的空间变化₅ -Fe ₂的Al _7.4硅相和较高的孔隙率会降低接头的抗失效能力，尤其是在AlSi12填料的情况下。Si的添加成功地提高了接头的润湿性，并且还降低了界面处IMC层的平均厚度。硬而脆的斜方晶η-的Fe形成₂的Al ₅和单斜θ-的FeAl ₃对于纯Al填料观察到这些化合物，而与富Si填料形成的脆性较低的三元Fe-Al-Si金属间相。在剪切拉伸试验过程中，观察到了三种破坏模式，分别在铝热影响区（HAZ）（由于软化），珠子（由于孔隙）和界面（由于差的润湿性/增加的脆性）引起。使用AlSi5填料以较低的接合速度和较低的WFR组合（即高WFR /速度比）形成的接头显示出更高且一致的机械性能。