Effect of Graphene Nanoplatelets Reinforcement on the Microstructure and Mechanical Properties of AlSi10Mg Alloy

Abstract

In this study, the effect of reinforcement of graphene nanoplatelets (GNPs that consist of a few graphene layers with a thickness of less than 100 nm and have extraordinary mechanical properties) on the microstructure and mechanical properties of AlSi10Mg alloy which is widely used in industry has been investigated. It is challenging to homogeneously disperse GNPs into liquid metals due to their large surface area and high surface energy. The GNPs have been incorporated into the liquid aluminum alloy with semi-solid mechanical mixing and dispersed into the matrix with ultrasonic processing. The microstructural analyses performed on the cast composites show that high intensity ultrasonic waves led to a relatively uniform dispersion of GNPs into the matrix by preventing their agglomeration, and a good bonding surface between the matrix and GNPs was obtained. In the tensile tests, it is seen that the addition of 0.25 wt.% GNPs has significantly increased the strength of alloy. The improvement in the strength is mainly attributed to the fact that GNPs act as barriers to the dislocation movement. The results show that the producibility of high performance GNPs reinforced metal matrix nanocomposites in liquid routes which is suitable for mass production.

Keywords

• Graphene nanoplatelets
• Metal matrix composites
• Nanocomposites
• Aluminum alloys
• Microstructure
• Mechanical properties