This study investigates the influence of nano-sized reinforcements on aluminum matrix composites’ mechanical and tribological properties. Microstructural analysis revealed that introducing nanoparticles led to grain refinement, reducing the grain size from 129.7 μm to 41.3 μm with 2 wt.% TiO₂ addition. Furthermore, ultrasonic-assisted squeeze casting of AA6061 composites reinforced with TiO₂ and Al₂O₃ resulted in a 52% decrease in grain size, demonstrating nano-reinforcements’ effectiveness in refining the matrix structure. Despite these advantages, the high surface energy of nanoparticles causes agglomeration, which can undermine composite performance. However, ultrasonic-assisted stir casting reduced agglomeration by approximately 80% compared to conventional stir casting, and cold isostatic pressing improved dispersion uniformity by 27%. The incorporation of nano-reinforcements such as SiC, Al₂O₃, and TiC significantly enhanced the material properties, with hardness increasing by ~30% and ultimate tensile strength improving by ~80% compared to pure Al. The hardness of nano-reinforced composites substantially rose from 83 HV (pure Al) to 117 HV with 1.0 vol.% CNT reinforcement. Additionally, TiC-reinforced AA7075 composites improved hardness from 94.41 HB to 277.55 HB after 10 h of milling, indicating a nearly threefold increase. The wear resistance of Al-Si alloys was notably improved, with wear rates reduced by up to 52%, while the coefficient of friction decreased by 20–40% with the incorporation of graphene and CNT reinforcements. These findings highlight the potential of nano-reinforcements in significantly improving the mechanical and tribological performance of n-AMCs, making them suitable for high-performance applications in aerospace, automotive, and structural industries.

This paper investigates the experimental analysis of concrete mixtures with different percentages of manufactured sand replaced for natural sand, with a focus on M25 and M30 grades. The study analyses various repairing times, with a special focus on 3, 14, and 28-day periods. The main conclusions show a clear pattern, with the maximum compressive strength for M25 and M30 grades being found at 50% and 100% replacement levels, respectively. This positive connection indicates that the amount of manufactured sand incorporation affects the compressive strength and shows its effect over different curing times. It is noteworthy that self-compacting concrete (SCC) made using crushed sand has a higher compressive strength than SCC made with natural sand. The study’s final findings, that emphasize the beneficial impacts of manufactured sand on SCC’s overall compressive strength characteristics, provide crucial data for enhancing concrete mix design. For the purpose of developing M sand, rocks are crushed to a similar size and form as natural sand or N-sand. The possible use of M-sand in SCC has been addressed in this paper. In this study, an effort has been made to analyze the potential use of M-sand in SCC. Self-Compacting Concrete (SCC) is a revolutionary concrete that allows for compaction and placement without the requirement for vibration. It may flow under its own weight even in the centre of dense reinforcement, entirely covering formwork and achieving full compaction. An attempt has been made to compare the characteristics of M35 self-compacting concrete in each its fresh and hardened states, substituting manufactured sand for river sand.