## 1 Introduction  
A hybrid joint made of dissimilar metals has been a focus of research in battery case manufacturing, and in the automotive and marine sectors for a long time [1, 2]. The synergistic qualities of the metals, as well as the creation of design efficient structures, are the primary driving forces behind this [3]. However, joining dissimilar metal combinations can be challenging because of inferior chemical compatibility and dissimilarities in physical properties. For example, when welding aluminum to steel, the interface between aluminum and (Al) iron (Fe) atoms throughout the welding process forms intermetallic compounds (IMCs) with high brittleness [4]. As the presence of these IMCs limits the strength of the joint, the amount of these compounds should be kept to a minimum. Furthermore, all fusion welding methods occur in transient conditions, and the time and temperature cannot be separately controlled. Moreover, the heat cycle applied to the weldment determines the thickness of the IMC layer and the width of the weld [5, 6]. Therefore, to regulate these two components, it is first necessary to understand the heat cycle and its effects. The advantages of iron (Fe) and aluminum alloys (Al) include excellent mechanical strength and corrosion resistance. As a result, they have a wide range of uses in maritime,automotive, and space applications [7]. Consequently, Fe-Al composite structures have received increasing interest as a means to amalgamate the positive characteristics of Fe with Al metal alloys. However, due to significant variations in material parameters, such as thermal properties, melting point, material characteristics, and grain morphology, effective Fe/Al welding conditions are hard to formulate and can generate Fe-Al phases with high brittleness [8; 9]. The main benefits of laser welding compared to arc welding are: (1) by adjusting the laser metal interaction, the dimension and melt pool geometry can be controlled, which would be difficult to achieve with an arc-welding method; (2) because of the high energy density in laser welding, a nominal heat-affected zone is created; (3) higher cooling and solidification levels compared to other fusion welding methods; and (4) localized and focused heating [10; 11; 12; 13; 14]. Furthermore, with gas tungsten arc welding (GTAW), managing the temperature ranges is not feasible as the temperature required to melt the aluminum will only wet the steel [15; 16; 17]. Traditional non-consembable techniques, such as GTAW or plasma, would not provide such control. Lasers are used for the cladding layers in many industries, e.g. the metal industry [18; 19; 20] and medicine [21; 22]. The process is also used in water environments [23; 24]. In addition, lasers are widely used in the fusion welding process to fabricate joints between duplex steel and aluminum alloys. Most studies have focused on minimizing Fe-Al IMC formation by regulating the beam offset position and distance to control the volume of the melted base material [25]. Other investigations have found that dual-beam welding improves the uniformity of IMC thickness, and that silicon helps decrease fractures in the weld. Nevertheless, none of the strategies listed above can prevent IMC development in Fe/Al interfaces. Furthermore, in dissimilar metal welding, a portion of the non-melted transitional layer remaining in the weldments butting surface will entirely avoid blending with parent materials [26]. The approach is non-ideal for lap-welding configuration with lasers [27]. As a result, novel welding processes must be investigated in order to efficiently regulate the development and growth of Fe-Al IMCs in the weld zone of the lap interface. Based on their high entropy impact, HEAs can enhance the development of solid solutions [28]. The mechanical characteristics of high-entropy alloys (HEAs) are directly connected to their structural stability. Therefore, proper monitoring of component composition is essential in understanding structural stability and determining mechanical characteristics.