## 3 Results and Discussion
From the loading/unloading curves, the micro-hardness (H) and the Young's modulus (E) were calculated, and the elastic recovery (E\({}_{\text{s}}\)) could be obtained from the area of the graph (Figure 12). E\({}_{\text{s}}\) can be obtained through the value of S\({}_{2}\)/(S\({}_{1}\)+S\({}_{2}\)), S\({}_{1}\) is the area inside A-B-C, and S\({}_{2}\) is the area inside B-C-D [34]. Thus, E\({}_{\text{s}}\) means the ratio of elastic strain recovered during unloading to the total energy consumed in plasticity and elasticity during loading, which means resistance to plastic deformation. H/E and H\({}^{3}\)/E\({}^{2}\) are also important values that determine the wear resistance of the coating and resistance to plastic deformation, respectively [35; 36]. Blocky particles of EEMMC1.5-T-P had higher values of factors, such as H, E, H/E, H\({}^{3}\)/E\({}^{2}\), and E\({}_{\text{s}}\), than particles of EEMMC1.0-T-P and EEMMC2.0-T-P. EEMMC1.5-T exhibited a significantly higher hardness than 900 HV, even with a 30% particle fraction. Therefore, the high hardness characteristics of EEMMC1.5 \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sample** & **Particle Morphology** & **Distribution Characteristics** & **Dominant Mechanism** & **Particle Fraction** \\ \hline EEMMC1.0-T, C, B & Blocky and dendritic and agglomerated spherical 1 & Inhomogeneous & Growth and coalescence & 14 \& 80 1 \\ \hline EEMMC1.5-T & Blocky & Unimodal & Equilibrium & \\ EEMMC1.5-C, B & Blocky and dendritic & Bimodal & Growth and dissolution & 30 \\ \hline EEMMC2.0-T, C, B & Blocky and dendritic & Sharp unimodal & Dissolution & 12 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Morphology, fraction, and formation mechanism of reinforcing particles. Figure 10: EPMA results for (**a**) EEMMC1.5-T and (**b**) EEMMC2.0-T.  
reactive cladding, in which the formation of the cladding layer and the formation of TiC reinforcing particles are synthesized simultaneously. The coating layer produced in this study had a thickness of 0.9 mm without severe interface defects, such as pores, cracks, and delamination. Important factors that determine the size and morphology of the reinforcing particles were the heat input of the laser and the depth of the cladding layer. EEMMC1.0, which had a low effective heat input, had a non-uniform coating depth and agglomerated reinforcing particles. EEMMC2.0, fabricated with an effective heat input of 66.7 J/mm\({}^{2}\), had fine-sized reinforcing particles due to dissolution by the high energy density, increasing the coating thickness and dilution with the substrate. Under the condition where the dissolution of particles was dominant, the closer to the substrate, the smaller the particles were and the sharper the particle distribution. In EEMMC1.5, manufactured at an effective heat input of 50 J/mm\({}^{2}\), no significant agglomeration or dissolution of the reinforcing particles was observed. Compared with the top part, the lower part had a broader and bimodal particle distribution due to the dendrite growth of large particles and the dissolution of small particles. Blocky-shaped particles of several micrometers are investigated in the coating layer. The layer exhibited high micro-hardness of 700-900 HV, especially at the top over 900 HV. As the depth of the coating layer increased, dendritic morphology developed, and hardness decreased slightly. In the nano-indentation results, the particles with blocky morphology and the matrix of EEMMC1.5 were 17 GPa and 10 GPa, respectively. Conceptualization, S.N. and Y.-M.K. ; methodology, S.N. ; formal analysis, S.N. ; investigation, S.N. and H.W.L. ; writing--original draft preparation, S.N. and H.W.L. ; writing--review and editing, S.N. and Y.-M.K. ; supervision, I.-H.J. and Y.-M.K. ; All authors have read and agreed to the published version of the manuscript. This research was funded by the Korea Institute of Industrial Technology as \"The dynamic parameter control based smart welding system module development for the complete joint penetration weld (KITECH EH-21-0003)\".