Abstract
Existing aluminium metal matrix composites (Al MMCs) can attain both high tensile yield strength (>500 MPa) and high elastic modulus (>90 GPa) but usually at the expense of tensile strain-to-fracture (~5% or less). Here we report the development of a novel class of Al MMCs that can offer tensile yield strength of 515 ± 17 MPa, elastic modulus of 95.6 ± 1.7 GPa and tensile strain-to-fracture of 10.4 ± 0.8%. Our design hypothesis is to reinforce the Al matrix with ex situ introduced carbon nanotubes (CNTs) for primary strengthening but at the same time we craft a high number density of in situ formed ultrafine γ-Al2O3 nanoparticles to improve dimple fracture. Together they act in concert to render outstanding tensile properties. The strengthening and failure mechanisms of the as-fabricated Al-CNTs-γ-Al2O3 MMCs are characterized in detail. The design concept proposed and validated in this study can be informative for the fabrication of other high-performance carbon-reinforced MMCs.
Original language | English |
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Article number | 107691 |
Journal | Composites Part B: Engineering |
Volume | 183 |
DOIs | |
State | Published - 15 Feb 2020 |
Keywords
- Carbon nanotubes and nanofibers
- Metal-matrix composites (MMCs)
- Nanoparticles
- Strength