## 1 Superalloy
### Evolution of Superalloys
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Class**} & \multirow{2}{*}{**Alloy**} & \multicolumn{10}{c}{**Compositions (wt.\%)**} \\ \cline{3-14}  & & **Cr** & **Co** & **Mo** & **W** & **Al** & **Ti** & **Ta** & **Nb** & **Re** & **Ru** & **Hf** & **C** & **B** & **Zr** & **Ni** \\ \hline \multirow{4}{*}{Conventional Cast (CC)} & IN-713 LC & 12 & - & 4.5 & - & 5.9 & 0.6 & - & 2 & - & - & - & 0.05 & 0.01 & 0.1 & Bal \\ \cline{2-14}  & IN-738 LC & 16 & 8.5 & 1.75 & 2.6 & 3.4 & 3.4 & 1.75 & 0.9 & - & - & - & 0.11 & 0.01 & 0.04 & Bal \\ \cline{2-14}  & René 80 & 14 & 9 & 4 & 4 & 3 & 4.7 & - & - & - & - & 0.8 & 0.16 & 0.015 & 0.01 & Bal \\ \cline{2-14}  & Mar-M247 & 8 & 10 & 0.6 & 10 & 5.5 & 1 & 3 & - & - & - & 1.5 & 0.15 & 0.015 & 0.03 & [PERSON] \\ \hline \multirow{4}{*}{DS} & \multirow{2}{*}{1 st} & Mar-M200 Hf & 8 & 9 & - & 12 & 5 & 1.9 & - & 1 & - & - & 2 & 0.13 & 0.015 & 0.03 & [PERSON] \\ \cline{2-14}  & CM247 LC & 8.1 & 9.2 & 0.5 & 9.5 & 5.6 & 0.7 & 3.2 & - & - & - & 1.4 & 0.07 & 0.015 & 0.007 & [PERSON] \\ \cline{2-14}  & \multirow{2}{*}{2 nd} & CM186 LC & 6 & 9.3 & 0.5 & 8.4 & 5.7 & 0.7 & 3.4 & - & 3.0 & - & 1.4 & 0.07 & 0.015 & 0.005 & [PERSON] \\ \cline{2-14}  & PWA1426 & 6.5 & 10 & 1.7 & 6.5 & 6 & - & 4 & - & 3.0 & - & 1.5 & 0.1 & 0.015 & 0.1 & [PERSON] \\ \hline \multirow{4}{*}{SC} & \multirow{4}{*}{1 st} & CMSX-2 & 8 & 5 & 0.6 & 8 & 5.6 & 1 & 6 & - & - & - & - & - & - & [PERSON] \\ \cline{2-14}  & PWA1480 & 10 & 5 & - & 4 & 5 & 1.5 & 12 & - & - & - & - & - & - & - & [PERSON] \\ \cline{1-1} \cline{2-14}  & René N4 & 9 & 8 & 2 & 6 & 3.7 & 4.2 & 4 & 0.5 & - & - & - & - & - & - & [PERSON] \\ \cline{1-1} \cline{2-14}  & AM1 & 7 & 8 & 2 & 5 & 5 & 1.8 & 8 & 1 & - & - & - & - & - & - & [PERSON] \\ \cline{1-1} \cline{2-14}  & RR2000 & 10 & 15 & 3 & - & 5.5 & 4 & - & - & - & - & - & - & - & [PERSON] \\ \cline{1-1} \cline{2-14}  & CMSX-4 & 6.5 & 9.6 & 0.6 & 6.4 & 5.6 & 1 & 6.5 & - & 3 & - & 0.1 & - & - & - & [PERSON] \\ \cline{1-1} \cline{2-14}  & PWA1484 & 5 & 10 & 2 & 6 & 5.6 & - & 9 & - & 3 & - & 0.1 & - & - & - & [PERSON] \\ \cline{1-1} \cline{2-14}  & [PERSON] N5 & 7 & 8 & 2 & 5 & 6.2 & - & 7 & - & 3 & - & 0.2 & - & - & - & [PERSON] \\ \hline \multirow{4}{*}{3 rd} & CMSX-10 & 2 & 3 & 0.4 & 5 & 5.7 & 0.2 & 8 & - & 6 & - & 0.03 & - & - & - & [PERSON] \\ \cline{1-1} \cline{2-14}  & TMS-138 & 2.9 & 5.9 & 2.9 & 5.9 & 5.9 & - & 5.6 & - & 4.9 & 2 & 0.1 & - & - & - & Bal \\ \cline{1-1} \cline{2-14}  & TMS-162 & 2.9 & 5.8 & 3.9 & 5.8 & 5.8 & - & 5.6 & - & 4.9 & 6 & 0.09 & - & - & - & Bal \\ \hline \multirow{2}{*}{5 th} & CMSX-7 & 6 & 10 & 0.6 & 9 & 5.7 & 0.8 & 9 & - & - & 0.2 & - & - & - & Bal \\ \cline{1-1} \cline{2-14}  & Low Re & CMSX-8 & 5.4 & 10 & 0.6 & 8 & 5.7 & 0.7 & 8 & - & 1.5 & - & 0.1 & - & - & Bal \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Composition of cast superalloys. Research has been conducted to improve the temperature stability of single crystal superalloys, leading to the development of sixth-generation single crystal superalloys. However, second-generation alloys such as CMSX-4, Rene N5, and PWA1484 containing three percent Re are the most commonly used. Re is a rare element that is obtained by mining and during the production of Cu or Cu/Mo. Ru is a precious metal that can be obtained during the production of platinum. Not only do these alloying elements considerably increase the price of single crystal superalloys but they also lead to the issue of limited economic and strategic supply. Therefore, recently, various studies have been conducted on alloys with superior characteristics with reduced Re content to lower the prices of such super alloys. As commercial alloys, CMSX-8 containing 1.5% Re and CMSX-7 containing no Re have been developed by Cannon Muskegon [3].