On the experimental investigation for mechanical properties of statically and dynamically compressed Ti-Al ₂ O ₃ nanocomposites

With recent advances in nanomaterials science, the development of nanocomposites has expanded to achieve materials with enhanced and tailored properties. Among them, metal-matrix nanocomposites reinforced with ceramic nanoparticles have attracted significant attention due to their improved mechanical and physical performance. Powder metallurgy is one of the most widely used methods for fabricating such materials, in which base metal powders are blended with nanoscale reinforcements and consolidated under controlled pressure and temperature. In this study, titanium was used as the matrix material, while alumina (Al 2 O 3 ) nano-powder served as the reinforcement at 0, 5, and 10 wt%. Ti-Al 2 O 3 nanocomposites were produced using both static and dynamic compaction methods. For dynamic compaction, the samples were subjected to impact velocities of 4.42, 6.26, and 7.66 m/s. Density measurements, scanning electron microscopy (SEM) observations of the microstructure and grain boundaries, compression tests, and hardness tests were performed to evaluate the material properties. The mechanical and microstructural properties were then analyzed and compared. The results show that the highest density was obtained in the sample containing 5 wt% Al 2 O 3 nano-powder dynamically compacted at 7.66 m/s. Microstructural observations indicate that, at constant compaction pressure, increasing the reinforcement content initially reduces porosity but increases it at higher nanoparticle concentrations. Hardness measurements under static compaction reveal that hardness increases with increasing compaction speed. Moreover, hardness increases with reinforcement addition up to 5 wt% but decreases at higher contents, a trend also observed in dynamically compacted samples. The addition of 5 wt% Al 2 O 3 nano-powder increased the compressive strength by 56%.