## 4 Discussion  
As stated in Section 2, the initial depositions followed a Taguchi L9 array between the scanning speed, feeding rate and laser power of the line beads; the parameters shown in Table 2 highlight four of the initial nine depositions, with their numbers being 1, 2, 6, 7 and 10, which were deemed the most interesting to further in additional DOEs: Track 1 displayed very large dilution values, attributed to its low relative scanning speed and low feeding rate. Track 2 also shows dilutions above the established limit of 30%, despite the larger scanning speed, attributing the dilution to the low feeding rate. Track 6 improved the dilution proportion by decreasing it to 42.41%, although the wettability angles were too large and disparate. Tracks 7 and 10 also proved unsatisfactory, with wettability angles that were overly large. The following DOE oscillated process parameters around Track 1, by creating another L9 Taguchi array with laser power values of 1250 W, 1400 W and 1550 W, scanning speeds of 3 mm s\({}^{-1}\), 6 mm s\({}^{-1}\) and 9 mm s\({}^{-1}\) and feeding rates of 5 g min\({}^{-1}\), 9 g min\({}^{-1}\) and 12 g min\({}^{-1}\). These depositions, of which Tracks 12 and 16 were analysed, yielded beads whose dilution proportion was too low and wettability angles too large, as easily perceptible through Figure 11, which shows the resulting outputs according to different parameters. The following depositions followed an orthogonal design and increased the scanning  
Figure 12: Examples of processed images with the elaborated algorithm (scale in pixels): the areas above and below the substrate are green and red, respectively; lines indicative of the width, height, substrate line, wettability angles and penetration limit are shown in blue. The images (a), (b), (c), (d), (e) and (f) are Tracks 1, 12, 32, 35, 41 an 56, respectively. Scale in the original image was added in post-processing and was not part of the image during the execution of the code. speeds while reducing the feeding rates: the ratio between scanning speed feeding rate was restricted to an interval between 0.018 and 0.06 m g\({}^{-1}\). Track 32 showed wettability angles that were too large, z possessed too large a dilution proportion, and finally Track 35 displayed acceptable values throughout. Further parameter variation ensued, with shielding gas flow rate, carrier gas flow rate, nozzle-to-substrate distance iterations resulted in beads with similar heights but considerably different dilution proportion and wettability angles; an increase in the disparity between the left and right angles in Track 56 could be attributed to the turbulence in the melting pool induced by the increase in shielding gas; Tracks 38 and 41 display large wettability angles, leading to the conclusion that very slow speeds (\(\leq\)3 mm s\({}^{-1}\)) may increase the skewness of the produced bead. Recent research [40] delved into the influence of the shielding gas flow rate on the porosity and quality of DED-produced 316L, concluding that the oxygen content present in the melt pool alters its surface tension, consequently affecting the melting pattern. The feeding rate proved to have a significant impact on the dilution proportion, a conclusion also found in the literature, although the observed phenomena was contrary to the one reported by another research work [30], in which an increase in feeding rate led to larger dilution proportions. However, considering that the increase in powder delivered to the melt pool requires more heat energy to melt, it is expected for the available energy to be less capable of melting the substrate. This conclusion is supported by similar research [41] that found the dilution proportion increases inversely when compared to the powder delivery per unit length. Additional research showed the possible instability due to excess power feed rate, which leads to poor overlapping [42]; track 7 and 10 highlight this problem, as their wettability angles are both greater than 90\({}^{\circ}\).