## 3 Results and Discussion
The coating layers of 0.6 mm, 0.9 mm, and 1.8 mm were obtained in EEMMC1.0, EEMMC1.5, and EEMMC2.0, respectively, and the thickness of the coating layer increased with increasing laser heat input (Figure 3). The coating thickness with in situ synthesized TiC by GTAC is usually 0.2-0.6 mm, and interface defects frequently occur [26]. In laser cladding with an in situ reaction, a coating layer of 0.6-1.8 mm thickness was prepared, which is similar to the thickness of the coating by laser cladding [12]. When comparing EEMMC1.0 and EEMMC1.5, the coating thickness increased in proportion to the laser power. However, the coating thickness of EEMMC2.0 increased significantly to 300% compared to that of EEMMC1.0. The higher the laser power, the greater coating thickness by dilution with the substrate. EEMMC1.0 were observed agglomeration of reinforcing particles as shown in Figure 3a. EEMMC1.0 is fabricated under low laser power, where it is difficult to distribute particles evenly. EEMMC1.0 has a relatively high standard deviation compared to a low coating thickness due to the irregular development of the coating layer interface and the internal microstructure. As an effective heat input increased above 50 J/mm\({}^{2}\), most agglomerated reinforcing particles seen in EEMMC1.0 were significantly reduced or disappeared. Figure 4 shows the XRD results for the phase analysis of the specimens. EEMMC1.0 detected three phases of TiC, gamma phase with a FCC structure, and an alpha phase with a BCC structure. The carbide formed in the coating layer in this process was TiC, which was consistent with the predicted stable equilibrium phase by thermodynamic calculations. The higher the laser output, the more the dilution with the substrate increased. The substrate AISI 304 stainless steel consisted of Fe-Cr-Ni as the main components and had a gamma phase. Therefore, the effect of increasing the content of Fe, Cr, and Ni should be investigated. In Fe-TiC alloy, secondary phases, such as Fe\({}_{2}\)Ti, are generated [27]. When Ni is added, Ti\({}_{2}\)Ni, NiTi, and Ni\({}_{3}\)Ti are developed [28; 29], and Cr\({}_{2}\)Ti is detected in Cr-Ti [30]. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample Name** & **Laser Power (kW)** &
\begin{tabular}{c} **Effective Heat** \\ **Input E\({}_{a}\) (J/mm\({}^{2}\))** \\ \end{tabular} & **Coating Thickness (mm)** \\ \hline EEMMC1.0 & 1.0 & 33.3 & 0.6 \(\pm\) 0.20 \\ EEMMC1.5 & 1.5 & 50 & 0.9 \(\pm\) 0.26 \\ EEMMC2.0 & 2.0 & 66.7 & 1.8 \(\pm\) 0.38 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Cladding conditions and average thickness of the coating layer of the samples. Because the metal matrix has a high configurational entropy and a fast cooling rate from the laser process, secondary phases could be suppressed. Therefore, no secondary phase picks were detected in XRD other than the main phases of gamma and alpha. The HEAs powder used in this study is a type 2, which has BCC and FCC phases, with the addition of high atomic radius elements, such as Al and Ti, to a type 1 (only FCC) [31]. In EEMMC1.5, the TiC peak as a reinforcing phase exists, and alpha and gamma phases are detected as a metal matrix phase. In EEMMC2.0, the TiC and alpha-related peaks almost disappeared, and only the gamma-related peaks developed. This is because the dilution with the substrate increased as the heat input increased. The cladding layers, EEMMC1.0, EEMMC1.5, and EEMMC2.0, were divided into three parts at 0.2-mm, 0.4-mm, and 0.8-mm intervals, respectively, considering the coating layer thickness in the depth direction. The top part (T) close to the surface, the central part (C), and the bottom part (B) close to the substrate were divided. The sample name with the position was indicated by appending T, C, and B after the sample name. For example, the top part of EEMMC1.0 was labeled as EEMMC1.0-T.