## 2 Experimental Approach
For the hybrid composite (Al/SiC\({}_{\text{P}}\)/Al\({}_{\text{2}}\)O\({}_{\text{3p}}\)), the two chosen reinforcing particles (SiC\({}_{\text{P}}\) and Al\({}_{\text{2}}\)O\({}_{\text{3p}}\)) revealed a combined effect on the compressive strength or stress, as shown in \[\rho_{AMCs}=\frac{\rho_{l}\times w_{AMCs}}{\Delta w_{AMCs}}. \tag{1}\]2 Alumina of 3 vol.% in an aluminum matrix and 3-7 vol.% SiC(Al/2 vol.% SiC\({}_{\text{P}}\)/3 vol.% Al\({}_{\text{2}}\)O\({}_{\text{3p}}\) and Al/7 vol.% SiC\({}_{\text{P}}\)/3 vol.% Al\({}_{\text{2}}\)O\({}_{\text{3p}}\)) revealed an improvement in both the compressive strength and ductility prior to a failure by fracture, as shown in Figure 8a,c. The Al/2 vol.% SiC\({}_{\text{P}}\)/8 vol.% Al\({}_{\text{2}}\)O\({}_{\text{3p}}\) and Al/7 vol.% SiC\({}_{\text{P}}\)/8 vol.% Al\({}_{\text{2}}\)O\({}_{\text{3p}}\) mMCs in Figure 8b,d, respectively, show a lower compressive strength. These composites were poorly densified at sintering temperatures of \(\leq\)650 \({}^{\circ}\)C, indicating an earlier fracture than others. Moreover, a higher volume percentage of reinforcements in the Al matrix  
\[\rho_{AMCs}=\frac{\rho_{l}\times w_{AMCs}}{\Delta w_{AMCs}}. \tag{1}\]3 Micrographs of the Al/7 vol.% SiC\({}_{\text{P}}\) mMCs sintered at 700 \({}^{\circ}\)C: (**a**) sintering time 30 min, 20\(\times\) magnification; (**b**) sintering time 30 min, 50\(\times\) magnification; (**c**) sintering time 90 min, 20\(\times\) magnification; (**d**) sintering time 90 min, 50\(\times\) magnification. at a lower sintering temperature were not densified, as revealed from their low density (Figure 3) and hardness values (Figure 4). In the powder metallurgy process, the aluminum particles were surrounded by the reinforcing SiC\({}_{\text{P}}\) and Al\({}_{2}\)O\({}_{3}\) particles. An excess in the addition of these hard, elastically deforming and brittle ceramic particles restricted their movement during compaction. The diffusion of the aluminum particles and their growth at the region of the neck was restricted by the reinforcing ceramic particles, which tended to lower the sinterability. This could be the reason for the lowering of the compression strength of the Al MMCs with a higher vol.% of reinforcements (>7 vol.% of SiC and >3 vol.% of Al\({}_{2}\)O\({}_{3}\)), as is shown in \[\rho_{AMCs}=\frac{\rho_{l}\times w_{AMCs}}{\Delta w_{AMCs}}. \tag{1}\]4  
The deformed and undeformed samples of the engineered composite material are shown in \[\rho_{AMCs}=\frac{\rho_{l}\times w_{AMCs}}{\Delta w_{AMCs}}. \tag{1}\]5 Barreling of the test samples was observed for both the Al/2 vol.% SiC/8 vol.% Al\({}_{2}\)O\({}_{3}\) and Al/7 vol.% SiC/8 vol.% Al\({}_{2}\)O\({}_{3}\) MMCs for all the sintering conditions. An increase in the sintering temperature did not influence the true stress due to the low sinterability of the engineered aluminum composites. Fractures on the circumference of the specimens were observed for all sintering conditions, except at a condition of 700 \({}^{\circ}\)C and 60 min for Al/2 vol.% SiC/3 vol.% Al\({}_{2}\)O\({}_{3}\) and Al/7 vol.% SiC/3 vol.% Al\({}_{2}\)O\({}_{3}\). It was seen that the size of the crack increased with an increasing vol.% of reinforcements. The crack on the circumference was perpendicular to the compression loading, indicating a brittle fracture. \[\rho_{AMCs}=\frac{\rho_{l}\times w_{AMCs}}{\Delta w_{AMCs}}. \tag{1}\]6 True stress versus true strain curves for the Al/SiC\({}_{\text{P}}\)/Al\({}_{2}\)O\({}_{3\text{p}}\) composite for the different sintering conditions.