## 3 Results and Discussion  
Figure 2 shows a cross-section of a laser-welded joint. The composition, fluidity, and surface tension of molten liquid aluminum and high-entropy alloy varied. As a result, it was not necessarily fully mixed, resulting in macro segregation [48; 49]. In addition, the shape of the fusion zone on the steel plate indicated conduction welds. The bead geometry also revealed that the depth of diffusion on the steel plate was less than half its thickness, indicating that no molten aluminum was mixed with molten steel during the joining process. The breadth of the aluminum fusion zone, as shown in Figure 2, determined the bonding area between steel and aluminum. The parent material melted acceptably on the hyper-duplex stainless-steel side [50]. As a result, no welding imperfections, such as fractures or pores were prolonged in the joint interface of the weldment. However, after solidification, an HEA zone was formed at the weld interface due to the melting of the HEAs during welding. Figure 3 depicts the XRD test results for the Fe\({}_{5}\)Co\({}_{20}\)Ni\({}_{20}\)Mn\({}_{35}\)Cu\({}_{20}\) high-entropy alloy zone. DSS and V solid solutions were the metallographic phases of the high-entropy alloy in the weldment. To limit and control the reactivity of steel and aluminum, a large amount of vanadium was added to the HEAs fillers in the butting surface of the lap joint [51; 52]. As a result, the large combining entropy of HEAs was able to improve elemental solubility. In addition, the high blending entropy effect of the HEAs powder produced random solid solutions over IMCs. As a result, the HEAs solidification phase comprised DSS and V solid solutions after welding. As illustrated in Figure 4, the interaction zone of HEAs/Al is represented in dark grey color; in Figure 5, the HEAs/Fe zone was relatively planar. The EDS curves at the joint interfaces of the HEAs/Al and HEAs/Fe are shown in Figures 6 and 7. Consistent with the Al-V phase diagram analysis, the EDS curve revealed the substrate at the HEAs/Al joint region, indicating a more significant presence of Al and V. The Al-V IMCs may be dispersed there [53]. The atom intensity of the HEAs/Fe interaction region remained constant. There was no base, which indicated that the atoms in the HEAs/Fe diffused together to generate a layer of diffusion throughout the welding process. In each zone, using EDS analysis, the configurations of the resultant material were measured, and the findings are given in Table 3. At area A in Figure 2, Al and V were 72.34 and 18.27 (wt. %), respectively, and the microstructure was Al\({}_{3}\)V. As a result, Al\({}_{3}\)V made up most of the multiple layers (nearly all were 0.7 \(\upmu\)m) at the interaction zone [54]. Figure 2: Cross-section of the laser-welded joint. A, B, C and D are the weld zones selected for SEM analysis. The Al-V IMCs performed effectively at room temperature. No Al element was identified at area B in Figure 2, suggesting that Al element diffusion had been inhibited. Because the HEAs contained many elements, this resulted in substantial lattice deformation in the grain configuration. The kinetic slow diffusion effect, caused by distortion in the structural lattice of HEAs, will obstruct atom mobility [55; 56]. Fe atoms visible in area C (Figure 2), but not in area E (Figure 2), indicated a tiny quantity of Fe atoms diffusing to the HEAs with a limited diffusion distance. The HEAs larger mixing entropy can improve element compatibility. A small amount of hyper-duplex stainless steel dispersed into the HEAs without creating any IMCs. Figure 4: SEM image of weld zone (from area A in Figure 2). i and ii are the areas where EDS performed. Figure 3: XRD test results for the Fe\({}_{5}\)Co\({}_{20}\)Ni\({}_{20}\)Mn\({}_{35}\)Cu\({}_{20}\) high-entropy alloy zone. Figure 5: SEM image of the weld zone (from area B in Figure 2). iii and iv are the areas where EDS performed. Figure 6: Weld interface SEM image (from area C in Figure 2). v is the areas where EDS performed.