## 3 Results
### Mass Balance  
Mass balance measurements and calculations were required for the quantification of the yields of Co and Al powders to the weld metal. The calculation procedure was as applied previously [15; 18; 19; 20]. The steel plate mass was recorded before and after welding, and the mass difference quantified the mass of weld wire and metal powder added to the weld metal. The etched cross-section was used to measure the weld metal areas above and below the base plate top surface, using stereoscope software applied to stereoscope images of the weld metal cross-section. The areas of both weld-metal cross-sections are marked in Figure 2: the area between lines A and B is the proportional area above the base-plate's top surface level. This is the proportion of the weld metal contributed by the weld wire and metal powder, namely Area 1. The proportional area between line B and line C is the proportion of the weld metal area contributed by melting of the base plate, namely Area 2. Here, as previously reported, this area proportion is defined as the dilution ratio and named (%DR(wire+MP)) [15; 18; 19; 20]. The geometric proportions of the weld bead as displayed in Figure 2 were 12.3 mm width and 6.7 mm height. The weld bead's total run length of 260 mm was made as a continuous bead-on-plate weld run. The mass of aluminium and cobalt powders added into the weld metal, respectively, were calculated by Equations (5)-(7). The weld metal composition in Table 3 was used as input for Equation (7). The expressions in Equations (5)-(7) illustrate the calculation sequence for aluminium:  
\[\%\text{DR}_{\text{(wire+MP)}}=\left(\frac{\text{A}_{\text{(wire+MP)}}}{\text {A}_{\text{(wire+MP)}}+\text{A}_{\text{BP}}}\right)*100=\left(\frac{\text{ Area1}}{\text{Area1}+\text{Area2}}\right)*100 \tag{5}\]  
\[\text{m}_{\text{WM}}=\left(\text{m}_{\text{wire}}+\text{m}_{\text{MP}} \right)*\left(\frac{100}{\%\text{DR}_{\text{(wire+MP)}}}\right) \tag{6}\]  
\[\text{(gram Al to WM)}=\left(\text{m}_{\text{WM}}\right)*\left(\frac{\%\text{ Al}_{\text{WM}}}{100}\right) \tag{7}\]  
WM = weld metal; MP = metal powder; BP = base plate; Wire = weld wire; m = mass (gram); A = area (mm\({}^{2}\))  
Similarly, the calculation for cobalt was made by using %Co in the weld metal, shown in Table 3, as input for Equation (7). From the gram masses of aluminium and cobalt powder added to the weld metal, as calculated from Equations (5)-(7), the percentage yield of each element to the weld metal was calculated from the initial input mass of 7 g of Al and 7 g of Co. Table 5 summarises the numbers applied in Equations (5)-(7), and the calculation results from Equation (7). The resultant percentage yields for Co and Al were 70% and 55%, respectively. Figure 2: Weld metal cross-section micrographs via stereoscope. Because reactions (2) and (3) are exothermic reactions, the extent of the heat contributions from these reactions was quantified to determine the possible temperature increase in the weld metal due to this added chemical heat. The added chemical heat values were calculated by first quantifying the mass of manganese and silicon added into the weld metal during these reactions, by using equation (8), as reported previously [15, 18, 19, 20]. Equation (8) shows the calculation for the mass of Mn added during aluminothermic reduction (M\({}_{\text{Mn}}\)).