Microstructure and Mechanical Properties of Multiphase Strengthened Al/Si/Al₂O₃/SiO₂/MWCNTs Nanocomposites Sintered by In Situ Vacuum Hot Pressing

Abstract

Eutectic Al–Si binary alloy is technically one of the most important Al casting alloys due to its high corrosion resistance, evident shrinkage reduction, low thermal expansion coefficient, high fluidity, and good weldability. In this work, multiphased Al–Si matrix nanocomposites reinforced with Al2O3and multiwalled carbon nanotubes (MWCNTs) have been sintered by anin situvacuum hot-pressing method. The alumina Al2O3nanoparticles were introduced by anin situreaction of Al with SiO2. Microstructure and mechanical properties of the sintered Al/Si/Al2O3/SiO2/MWCNTs nanocomposites with different alumina contents were investigated. The mechanical properties were determined by micro-Vickers hardness and compressive and shear strength tests. The results demonstrated thatin situalumina and MWCNTs had impacts on microstructure and mechanical properties of the nanocomposites. Based on the mechanical properties and microstructure of the nanocomposites, strengthening and fracture mechanisms by multiple reinforcements were analyzed.

Microstructures and mechanical properties of Cu/Ti3SiC2/C/graphene nanocomposites prepared by vacuum hot-pressing sintering and hot isostatic pressing

“…Most studies on copper matrix composites have thus far focused on single reinforcements [14][15]. However, the enhancement effect of single reinforcements cannot meet the requirements for its application, whereas the comprehensive functions of two or multiple reinforcements can be considered [16][17].…”

“…Graphene is recognized for its strength at the nanoscale level. Adding graphene to the Cu-C matrix may produce synergistic, cooperative, and multi-scale reinforcements [4][5][6][7][8][9][10][11][12][13][16][17]. The choice of reinforcement and design significantly influences the performance of the composite.…”