## 1 Introduction  
Additive manufacturing (AM) is defined as a process of manufacturing three-dimen signal components from a computer-aided design (CAD) file by adding materials layer-by-layer. As per International Organization for Standardization (ISO) [1], which provides standard terminology for AM, it can be broadly categorized into seven processes: one of them is directed energy deposition (DED). DED is one class of AM in which a focused thermal energy source such as a laser, arc, or electron beam is used to melt the material, and they are selectively deposited. The DED process utilizes metallic material in the form of powder or wire as feedstock. Wire arc additive manufacturing (WAAM) is one type of DED process that uses an electric arc as thermal energy to melt the feedstock material in wire form. WAAM is renowned for its high deposition rate, cost-effectiveness, and ease of material handling [2]. It is possible to achieve a near-net shape with WAAM, and with the addition of the machining process, a net shape can be manufactured, and the process becomes hybrid [3]. A major advantage of using WAAM is the broad scope of material processing. However, there exist various challenges with WAAM in terms of residual stress due to high heat input [4; 5], porosities [6; 7], humping [8], corrosion [9], and other mechanical properties. The WAAM process can be categorized into three prominent categories based on the type of arc used to melt the wire electrode, i.e., gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), and plasma arc welding (PAW). Cold metal transfer (CMT) welding is an advanced version of the GMAW process based on the short-circuit metal transfer mode. This process was developed by Fronius in 2004. The CMT process is renowned for producing lower heat input and higher arc stability through an innovative wire feed setup and a digital control system. In this process, droplet detachment occurs mechanically. Furthermore, when the electrode wire tip comes into contact with the metal's molten pool, \"robacter drive\", the servomotor reverses the filler wire by digital process control. Thus, it causes the wire to retract and generate droplet cutting; meanwhile, the current value reduces swiftly to nearly zero, and in this way, CMT causes reduced heat input and minimized sputtering during material deposition [10]. The CMT process can be further categorized into five types: CMT-conventional, CMT-advance, CMT-pulse (CMT+P), CMT-pulse advance, and CMT-dynamic. The CMT+P process merges a pulse cycle with a CMT cycle, producing more heat. However, various parameters in the CMT+P influence the properties of the molten metal pool in different ways, affecting the micro/macrostructure of the final weld bead. These parameters of CMT+P include pulse correction (PC) and arc length correction (ALC). PC affects the droplet's detachment forces in the process, and in Fronius--TPS 5000 machine (Fronius, Wels, Austria-based company), it ranges from \(-5\) to \(+5\). Specifically, few pulses per second (low frequency), high current, and high droplet detachment forces describe \(+5\) PC. On the other hand, more pulses per second (high frequency), low current, and low droplet detachment forces describe \(-5\) PC. ALC can be defined as the percentage of electrode wire oscillation that alters the arc length and, hence, the arc formation. Arc length can be defined as the distance between the tip of the wire electrode and the substrate, as described in Figure 1. Arc length affects the heat transfer to the substrate [11], the bead's penetration behavior [12], and spatters [13] during the material deposition process. In the case of the short arc length, the droplets may come into contact with the molten pool while still on the electrode wire and, hence, may lead to a short circuit [14]. Furthermore, if the arc length is too long, the arc's stability may be affected, and oxidation of the molten metal may occur [15]. This may lead to different defects in the weld bead, such as porosity, penetration, etc.