## 2 Experimental  
### Intermediate Alloy Preparation  
The powders needed to prepare the intermediate alloy were Ti, C, KBF\({}_{4}\), K\({}_{2}\)TiF\({}_{6}\), and B\({}_{4}\)C powder. The Al-13 Si-5 Cu-1 Mg-2 Ni matrix alloy was prepared using highly pure Al (99.95 wt. %), pure Mg (99.9 wt. %), pure Si (99.9 wt. %), Al-50 wt. % Cu, and Al-10 wt. % Ni master alloys. The matrix alloy preparation process also used Al-20 wt. % Ce, Al-P alterative, mischmetal rich in La and Ce, and Hexachloroethane. Table 4 are the powders used to prepare intermediate alloys. For Al-Ti-C intermediate alloy, Ti powder and C powder in a Ti:C = 4:1 mass ratio and 10 wt. % were used. Al were measured according to the reaction formula:  
\[\mathrm{Ti+C\to TiC} \tag{1}\] \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Powders** & **Particle Size** & **Purity** & **Manufacturer** \\ \hline Al & 200 mesh & \(\geq\)99.0\% & Shanghai shanpu chemical Co., Ltd. (Shanghai, China) \\ Ti & 200–300 mesh & \(\geq\)99.0\% & Sinopharm chemical reagent Co., Ltd. (Shanghai, China) \\ C & 2000 mesh & \(\geq\)99.9\% & Tianjin Kemiou Chemical Reagent Co., Ltd. (Tianjin, China) \\ K\({}_{2}\)TiF\({}_{6}\) & / & \(\geq\)99.0\% & Shanghai SSS Reagent Co., Ltd. (Shanghai, China) \\ KBF\({}_{4}\) & / & \(\geq\)99.0\% & Shanghai SSS Reagent Co., Ltd. (Shanghai, China) \\ B\({}_{4}\)C & 100–300 mesh & \(\geq\)99.0\% & Nangong ruiteng alloy material Co., Ltd. (Nangong, China) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Raw materials for chemical reagents in the experiment. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Reinforcement Types** & **Advantages** & **Disadvantages** \\ \hline Al-Ti-B & 1. & High refinement efficiency that is 12 times better than that of Al-Ti & 1. & Accumulation of TiB\({}_{2}\) can impair the quality \\
2. & TiAl\({}_{3}\) and TiB\({}_{2}\) are heterogeneous crystal cores of & 2. & ”Poisoning” by Zr, Cr, and Mn can lead to failure \\ \hline Al-Ti-C & 1. & Non-contaminating addition of a refinement agent & 1. & Poor attenuation \\
2. & ”Immune” to Zr, Cr, and Mn & 2. & Refinement effect worse than that of Al-Ti-B \\ \hline Al-Ti-B-C-Ce & 1. & They have all the above mentioned advantages & \\ Al-Ti-B-C-Ce & 2. & Particle size is refined by adding rare earth to & 1. & Research not yet well developed \\  & & prevent aggregation and precipitation of TiAl\({}_{3}\) and TiB\({}_{2}\) & 1. & Research not yet well developed \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Characteristics of reinforcements. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Materials** & **Enhanced Phase** & **Tensile** & **Elongation\(\delta\)/\%** & **Reference** \\ \hline TiC/Al & 15 & 610 & 4.9 & [28] \\ TiC/Al-4.5 Cu & 20 & 540 & 18 & [29] \\ TiB\({}_{2}\)/Al & 16 & 349 & 3.8 & [30] \\ TiB\({}_{2}\)/Al & 5 & 124 & 9.2 & [31] \\ TiB\({}_{2}\)/Al & 2.5 & 290 & 10 & [32] \\ TiB\({}_{2}\)/A356 & 5 & 302 & 9 & [32] \\ TiB\({}_{2}\)/A356 & 7.5 & 317 & 8 & [32] \\ TiB\({}_{2}\)/A356 & 10 & 328 & 6 & [32] \\ TiB\({}_{2}\)/ZL109 & - & 258.7 & 7.5 & [33] \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The tensile properties of different in-situ reinforced aluminum matrix composites at room temperature. \[\mathrm{Al}+\mathrm{Ti}\rightarrow\mathrm{Al}_{3}\mathrm{Ti} \tag{2}\] \[\mathrm{Al}+\mathrm{C}\rightarrow\mathrm{Al}_{4}\mathrm{C}_{3} \tag{3}\]  
These powders were mixed uniformly in a mortar and poured into a stainless-steel briquette mold (\(\Phi\) 35 mm \(\times\) 10 mm). The powder was pressed to form a powder briquette. The briquette was dried and placed in molten pure aluminum liquid at 1000 \({}^{\circ}\)C, for an in-situ reaction to produce Al-3 Ti-0.25C intermediate alloy. For Al-Ti-B intermediate alloy, \(\mathrm{KBF}_{4}\) and \(\mathrm{K_{2}TiF}_{6}\) were blended according to the reaction formula and stirred directly into 850 \({}^{\circ}\)C pure molten aluminum. The in-situ reaction then occurred in molten aluminum to produce the Al-Ti-B intermediate alloy.