In this study, aluminium matrix hybrid composites (AMHCs) containing 10 wt-%SiC microparticles and $x$ wt-%TiB₂ ( $x$ = 1, 3 and 5) nanoparticles were fabricated by powder metallurgy. The effect of TiB₂ content on microstructure and mechanical properties were examined by a combination of scanning electron microscopy, transmission electron microscopy and tension tests. The results showed that mechanical properties of the hybrid composites were improved with increasing the content of TiB₂ nanoparticles. Compared to aluminium matrix composites reinforced with mono SiC microparticles, the ultimate tensile strength and yield strength of the AMHCs with additional 5 wt-% TiB₂ nanoparticles were increased by 64 and 23%, respectively. Based on the fractographs, the relevant fracture mechanism was also discussed.

The size and distribution of ceramic particles in aluminum matrix composites have been reported to remarkably influence their properties. For a single ceramic particle, the particle size is too small and prone to agglomeration, which makes the mechanical properties of the composites worse. When the ceramic particle size is too large, the particles and alloy at the interface are not firmly bonded, and the effect of dispersion distribution is not achieved, which will also reduce the mechanical properties of the composites. The multi-size ceramic particles are expected to improve this situation, while their effect on hot workability is less studied. In this study, the hot deformation behavior, constitutive model, processing map and SEM microstructure were investigated to evaluate the hot workability of multi-size SiC particle-reinforced 6013 aluminum matrix composites. The results showed that the increased deformation temperature and decreased strain rate could decrease flow stresses. The flow stress behaviors of the composites can be described by the sine-hyperbolic Arrhenius equation with the deformation activation energy of Q = 205.863 kJ/mol. The constitutive equation of the composites is $\dot{\epsilon }=3.11592\times {10}^{13}{\left(\sinh \left(0.024909\mathsf{\sigma }\right)\right)}^{4.12413}\exp \left(-\frac{205863}{RT}\right)$. Then, the hot processing map of the SiCp/6013 composites was constructed and verified by SEM observations. The rheological instability zone was in the region of a high strain rate. The optimal processing zone for composites was 450~500 °C and 0.03~0.25 s⁻¹. In addition, the strain level was found to increase both the Q value and the area of the instability zone.

SiC_p/Al-Fe-V-Si composites exhibit complex deformation behaviors at both room and high temperatures because of the presence of SiC reinforcement particles and numerous fine dispersed Al₁₂(Fe, V)₃Si heat-resistant phases. In this work, an artificial neural network (ANN) constitutive model was established to study the deformation behavior of SiC_p/Al-7.75Fe-1.04V-1.95Si composites over a wide temperature range based on uniaxial compression. Then, microstructural observation, finite element analysis, and processing maps were utilized to investigate the plastic workability. The results showed that the ANN model fit the experimental stress–strain curves with high accuracy, achieving an R² value of 0.999. The ANN model was embedded into finite element software to study plastic deformation behaviors, which indicated that this model could accurately compute the plastic and mechanical response during the compressing process. Finally, a thermomechanical processing diagram was developed, revealing that the optimal processing parameters of the SiC_p/Al-7.75Fe-1.04V-1.95Si composites were a deformation temperature of 450–500 °C and a deformation rate of 0.1–0.2 s⁻¹.