## 3 Results
### Evolution of Mechanical Properties  
#### 3.4.1 Compressive Response  
The room temperature compression test was used to calculate the Young's modulus (\(E\)), yield strength (\(\sigma_{y}\)), ultimate compressive stress (\(\sigma_{s}\)), compressive plastic strain (\(\varepsilon_{s}\)), and strain hardening capacity (\(\sigma_{s}\)-\(\sigma_{y}\)) of the composite (Table 2). The compression engineering  
Figure 4: Electron back-scattered diffraction images of corresponding scanning electron microscopy image shown in (**a**). (**b**) shows the phase fraction map, and (**c**) orientation map along with the inverse pole figure images.  
stress-strain curve displayed in Figure 5a exhibits [PERSON]'s modulus (\(E\)) of 212 GPa, a uniform deformation with \(\sigma_{y}\) of 108 MPa and \(\sigma_{s}\) of 284 MPa without sacrificing plasticity (\(\epsilon_{s}\)) of 17%. A close inspection shows a significant strain hardening capacity (\(\sigma_{s}\)-\(\sigma_{y}\)) of up to 176 MPa in the composite, enabling good load-bearing capacity during plastic deformation and delaying the failure. In addition, serrated plastic flow (Luders' strain) can be observed in the strain-hardened regions (marked in Figure 5a). Interestingly, such observed capacity (\(\sigma_{s}\)-\(\sigma_{y}\)) is higher than the values observed for TiB\({}_{2}\) (1-4 vol.%)-reinforced Ti matrix composites showing (\(\sigma_{s}\)-\(\sigma_{y}\)) = 105-113 MPa [48]. The work hardening capacity (\(\sigma_{c}\)) was measured as (\(\sigma_{c}\) = (\(\sigma_{s}\)/\(\sigma_{y}\)) \(-\) 1) 1.63, indicating better load-bearing ability in the composite than other particulate reinforced composites (Table 2) [49; 50]. Furthermore, \(\sigma_{c}\) is strongly correlated to its yield strength. This relationship is governed by the Hall-Petch relationship, which considers both grain size and dislocation density contrast factor between adjacent grains [49]. Therefore, it appears that an increase in the grain size, i.e., hard CG/clusters reinforcements, can significantly lower the \(\sigma_{y}\) (easier to deform initially) but has a greater potential to increase the strain hardening capacity \(\sigma_{c}\) in Al\({}_{3}\)BC/Al composites [50]. A close-up of the engineering stress-strain diagram reveals a serrated plastic flow, which indicates potential key occurrences of the formation of high-density dislocations, and initiating dislocation plasticity events [23; 24].  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Alloy** & \(\begin{array}{c}\sigma_{y}\\ \text{(MPa)}\end{array}\) & \(\begin{array}{c}\sigma_{s}\\ \text{(MPa)}\end{array}\) & \(\epsilon_{s}\) **(\%)** & **H (GPa)** & **E (GPa)** & \(\sigma_{c}\) & **R** & **Ref.** \\ \hline Al\({}_{3}\)BC/Al & & 108 & 284 & 17 & \(15\pm 5\) & 212 & 1.63 & 5.6 & Present study \\ \hline Ti/1 TiB\({}_{2}\) & 750 & 856 & 10 & - & 128 & 0.14 & - & [12] \\ \hline Ti/4 TiB\({}_{2}\) & 576 & 689 & 27 & - & 103 & 0.20 & - & [12] \\ \hline Al/15 Mg\({}_{2}\)Si & & & & & & & & \\ Sintering + Hot extrusion & 114 & 200 & 7 & - & 75 & 0.75 & - & [17] \\ \hline Al/20 SiC & & & & & & & & \\ Sintering + Hot extrusion & 64.6 & 127 & 7 & - & - & 1.00 & - & [51] \\ \hline Al/20 Al\({}_{2}\)O\({}_{3}\) SPS & - & 96 & - & - & - & - & - & [10] \\ \hline Al/AlN\({}_{\text{P}}\) RT & 179 & 251 & - & 14 & - & 0.40 & - & [13] \\ \hline \hline \end{tabular}
\end{table}
Table 2: Mechanical properties of the composites and their comparison with published reports.  
Figure 5: (**a**) Stress-strain curve shows a high yield strength of up to 108 MPa and ultimate compressive strength of up to 284 MPa, with plasticity reaching 17%. Inset: serrated flow potentially categorized to Type-B serrations. (**b**) Strain hardening behavior of the composite shows multiple strengthening mechanisms (insets showing the two-phase strain hardening behavior).