## 3 Results
### Mass Balance  
The following mass measurements and mass balance calculations were made to quantify the yield of Ni and Al to the weld metal. This calculation procedure is the same procedure applied previously [26, 27, 28]. The steel plate mass was recorded before and after welding, and the mass difference then quantifies the mass of weld wire and metal powder added to the weld metal. A cross section cut of the weld metal was polished to a mirror \begin{table}
\begin{tabular}{c c c c c c} \hline  & **\%Si** & **\%Mn** & **\%Al** & **\%Ni** & **\%Fe** \\ \hline a & 0.83 & 1.37 & 2.40 & 7.29 & 87.8 \\ b & 0.80 & 1.70 & 2.60 & 7.21 & 87.7 \\ c & 0.80 & 1.60 & 2.50 & 7.30 & 87.8 \\ \hline \end{tabular}
\end{table} 
Table 4: SEM-EDS analyses of marked areas in the weld metal as indicated in Figure 1 (mass%). Figure 1: SEM micrograph of weld metal with analysed areas marked. (See Table 4 for the analyses of the marked phase areas: a–c) (\(\times\)3000). finish and then etched with 2% Nital solution to reveal the weld metal boundary in the base plate. The etched cross section was used to measure the weld metal areas above and below the base plate top surface level from stereoscope images of the weld metal cross section, using the stereoscope software. The areas are marked in Figure 2 for both weld metal cross section images: the area between line A and line B is the proportional area above the base plate 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 the melting of the base plate, namely Area 2. Here, this area proportion is defined as the dilution ratio as previously reported and named (%DR(wire+MP)) in the following expressions [26; 27; 28]. The mass Al and Ni added to the weld metal were calculated from Equations (5)-(7). The weld metal composition in Table 3 is used as input to Equation (7). The expressions in Equations (5)-(7) illustrate the calculation sequence for aluminium. Similarly, the calculation for nickel is made by using the %Ni in the weld metal from Table 3 as input to Equation (7). \[\%\text{DR}_{(\text{wire+MP})}\ =\ \left(\frac{\text{A}_{(\text{wire+MP})}}{ \text{A}_{(\text{wire+MP})}+\text{A}_{\text{BP}}}\right)\times 100\ =\ \left(\frac{\text{Area1}}{\text{Area1+Area2}}\right)\times 100 \tag{5}\]  
\[\text{m}_{\text{WM}}\ =\ (\text{m}_{\text{wire}}+\text{m}_{\text{MP}})\times \left(\frac{100}{\%\text{DR}_{(\text{wire+MP})}}\right) \tag{6}\]  
\[(\text{gram Al to WM})\ =\ (\text{m}_{\text{WM}})\times\left(\frac{\%\text{ Ai}_{\text{WM}}}{100}\right) \tag{7}\]  
WM = weld metal; MP = metal powder; BP = base plate; Wire = weld wire; m = mass (gram); A = area (mm\({}^{2}\)). Once the grams of Al and Ni added to the weld metal are calculated from Equations (5)-(7), the percentage yield of each element to the weld metal is calculated from the initial input mass of 7 grams of Al, and 7 grams of Ni. Table 5 summarises the numbers applied in Equations (5)-(7), and the calculation results from Equation (7). The resultant percentage yield numbers for Ni and Al are 85% and 45%, respectively. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & **Al** & **Ni (g)** & **Powder** & **Wire (g)** & **BasePlate** & **Weld** & **\%DR(wire+MP)** & **\%Al** & **\%Ni** \\  & **(g)** & **Ni (g)** & **Wire (g)** & **Wire (g)** & **Wired** & **(g)** & **Yield** & **Yield** \\ \hline Base Case & 0 & 0 & 0 & 33.8 & 33.8 & 67.6 & 50 & 0 & 0 \\ MP6 & 3.2 & 6.0 & 9.2 & 50.7 & 26.4 & 86.3 & 69 & 45 & 85 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Mass balance numbers for percentage yield calculation. Figure 2: Weld metal cross section micrographs via stereoscope. The exothermic reaction heat contributions from Equations (2) and (3) are calculated by first quantifying the mass of Mn and Si added to the weld metal from these reactions by using Equation (8) as reported previously [26; 27; 28].