Strength-ductility trade-off via SiC nanoparticle dispersion in A356 aluminium matrix

Abstract

A process was developed to disperse β-SiC nanoparticles (NPs), with a high propensity to agglomerate, within a matrix of A356 aluminum alloy. A suitable dispersion of 1 wt.% SiC NPs in the A356 matrix was obtained through a hybrid process including a solid-state modification on the surface of the NPs, a two-step stirring process in the semi-solid and then the liquid-state, and a final hot-rolling process for fragmentation of the brittle eutectic silicon phase and porosity elimination. Titanium and nickel where used as the nanoparticle SiC surface modifiers. Both modifiers were found to improve the mechanical properties of the resulting material, however, the highest improvement was found from the nickel surface modification. For the nickel modification, compared to the non-reinforced rolled alloy, more than a 77 %, 85 %, and 70 % increase in ultimate tensile strength (UTS), yield strength (YS), and strain % at the break, respectively were found with respect to the unreinforced rolled A356. For the rolled nanocomposite containing 1 wt. % SiCnp and nickel modification, an average YS, UTS, and strain % at the break of 277MPa, 380 MPa, and 16.4% were obtained, respectively, which are unique and considerable property improvements for A356 alloy.

Effect of carbide ceramics and coke on the properties of dispersion strengthened aluminium‐silicon7‐magnesium hybrid composites

“…A process to disperse silicon carbide nano‐particles within aluminium‐silicon7‐magnesium/aluminium alloy matrix was developed. Substantial enhancement in the mechanical properties was observed in the nickel surface modification composites [11].…”

Comparative analysis of sliding wear behaviour of A356 nanocomposites using response surface methodology and artificial neural network approaches

“…To be specific on A356 alloy considerable amount work has been carried out to study the influence of various nanosize reinforcing phases such as TiB 2 , Al 2 O 3 , Si 3 N 4 , SiC, MgO, ZrO 2 , carbon nanofibers and carbon nanotubes on mechanical and tribological properties [18][19][20][21][22][23]. Mousavian et al [24] reported development of Ni and Ti surface modified SiC reinforced A356 composites using hot rolling process. The nanocomposite with 3% SiC content showed highest tensile strength of 380 MPa and this enhancement in strength was attributed to Orowan strengthening mechanism.…”

Microstructure evolution and strengthening mechanism of A356 composites reinforced with micron and nano SiCp

“…As for nano particles, they have obvious size effect, thereby drastically improving the strength, plasticity and toughness of AMCs. However, the composites reinforced by nano particles are difficult to be prepare since nano particles are easy to agglomerate, limiting their application scopes [8,9]. In this case, the addition of micron and nano particles simultaneously into AMCs helps to solve the problem of insufficient strength and toughness, which is of great significance to promote the development of lightweight and wear-resistant AMCs [10,11].…”