## 3 Results and Discussion  
### Geometrical Analysis  
Firstly, the received single clades were subjected to a visual assessment in order to select the appropriate technological parameters. The visual analysis indicated the presence of macrocracks in samples no. 2 and 3 (Figure 6). According to [26], the cracking of the HSS material during DED can be due to hot or cold cracking. The microstructure analysis did not show the occurrence of microcracks at prior austenite grain boundaries, which is typical for hot cracks in this kind of material. In contrast, macrocracks in the heat-affected zone are a characteristic representation of cold cracking in the DED process. This may be a result of the relatively high residual stresses caused by the rapid solidification of a significant amount of material. The susceptibility to cracking is additionally increased by the high carbon content in processed materials and an unfavorable cladding structure that results in geometric notches. On this basis, these two sets of parameters were excluded from further studies. Despite the absence of cracks for the remaining seven sets of parameters for single clades, the geometric requirement (clad height \(\geq\) 2.5 mm) was not met (Figure 7a). Therefore, there was a necessity for the multilayer CLWD process to achieve this requirement. Figure 5: Schematic of the research methodology for the development of additive regeneration technology for the HSS-Co PM cutting tools using the CLWD process. The clad height increases with the wire feed rate, whereas it decreases as the travel speed rises. This enables one to determine the dependence between the clad height and the WFRC parameter, which is shown in Figure 7c. A linear correlation with a high R\({}^{2}\) value (> 0.99) was found. Regardless of the set of parameters used, the width of the clad remains at the same level (Figure 7b). Furthermore, the minimal requirement for the width of the remanufactured clad was fulfilled (>4.0 mm). It can be concluded that for a WFRC coefficient higher than 14, cracking can occur. One of the important factors in the process of multilayer laser metal deposition is the strategy of material deposition. It can allow one to avoid the stress concentration caused by the nonuniform build-up of successive layers. Therefore, subsequent clades were deposited with laser beam movement in opposite directions. The use of the mentioned approach may allow for a uniform geometry of the clad along its length and a resulting more beneficial stress distribution. Figure 8 shows the results of the multilayer CLWD process considering the number of layers, their gradual height, and the occurrence of cracks. As the number of layers increases, a significant decrease in the quality of the deposited structures can be observed, as revealed by the presence of cracks. Only for the parameter set with the highest travel speed and the lowest wire feed rate (no. 7), a crack-free two-layer structure was obtained. It can be observed that for the eighth and ninth parameter sets, cracking occurred for two-layer structures, while the clad heights for these trials have been close to the height of the single crack-free clad no. 1. This suggests an increased contribution of residual stresses to the crack formation process for the two-layer deposition process. Figure 6: A view of the deposited single clades with 9 different sets of process parameters. Figure 8: Results of the deposition of multilayer clad structures—clad heights obtained for the deposition of 1, 2 or 3 layers of additional material. Figure 7: Results of measurements of geometrical properties of single clads with different parameter sets: (**a**) results of the clad height measurement, (**b**) results of the clad width measurement, (**c**) linear correlation between the clad height and the complex process parameter.