Microstructure and Mechanical Properties of Multiphase Strengthened AlSiAl2O3SiO2MWCNTs Nanocomposites Sintered by In Situ Vacuum Hot Pressing

Abstract EN

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 Al2O3 and multiwalled carbon nanotubes (MWCNTs) have been sintered by an in situ vacuum hot-pressing method.

The alumina Al2O3 nanoparticles were introduced by an in situ reaction 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 that in situ alumina 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.