Effect of Graphite and/or Silicon Carbide Particles Addition on the Hardness and Surface Roughness of Al-4 wt% Mg Alloy

Abstract

In this study, the fabrication of Al-4 wt% Mg-graphite and/or silicon carbide (SiC) particulate composites is described. Composites of Al-4 wt% Mg alloy with different volume percentage values of graphite and/or SiC particles are prepared using the compocasting technique. In this technique, graphite particles and/or SiC particles are added into a semi-solid slurry during the stirring of the melt. A pitched blade stirrer is used to stir the reinforcement particles in the slurry. The slurry is then poured in a metallic mold to obtain the cast composites. The effect of the addition of graphite and/or SiC particles and porosity content on the Rockwell hardness and machinability is studied in the present work. The results show that the porosities increase with increase in particles content while Rockwell hardness decreases with increase of graphite particles. But SiC particles are found to increase the hardness of composites. Surface roughness improves with graphite content in the cast composite, and poor surface finish is obtained when SiC particles are added.

Prediction of density, porosity and hardness in aluminum–copper-based composite materials using artificial neural network

“…The major limitation in many cases in fabricating metal matrix composites by liquid phase route resides upon the incompatibility of the reinforcement and the matrix (Candan and Bilgic, 2004;Hassan et al, 2007). This problem in case of Al-based metal matrix composite is due to the formation of stable tenacious oxide film, resulting in poor wettability with the ceramic particle.…”

Effect of Copper and Silicon Carbide Content on the Corrosion Resistance of Al-Mg Alloys in Acidic and Alkaline Solutions

“…The intermetallic precipitates that may found during casting process are Al 4 C 3 and free Si-type intermetallic, the contribution of such hard intermetallic precipitates is to increase corrosion rate in monolithic aluminum alloys and matrix composites [2,8]. …”

“…Specific quantities of silicon carbide powder with an average particle size of 75μm and purity exceeds 99.5% of 5 and 10 vol.% were added to the matrix alloy. Magnesium ingots (~99% purity) was added in small quantities (fixed weight percentage 4wt.%) to promote wettability between metal matrix and reinforcement particles [2,10].…”

“…Studying corrosion resistance of Al-based materials is important especially for automotive and aircraft applications where the parts are prone to corrosive media like salt water solutions, acidic and alkaline media. Aluminum based composites are usually reinforced by Al 2 O 3 , SiC, and C. The major advantages of AMCs compared to unreinforced materials are as follows: greater strength, improved stiffness, reduced density, good corrosion resistance, improved high temperature properties, controlled thermal expansion coefficient, thermal/heat management, improved wear resistance and improved damping capabilities [1][2][3][4][5][6]. Nowadays, the increased demand for light weight components, primarily driven by the need to reduce energy consumption in a variety of societal and structural components, has led to an increase in the use of aluminum.…”

“…The major limitation in many cases in fabricating metal matrix composites by liquid phase route resides upon the incompatibility of the reinforcement and the matrix [1][2][3]. This problem in case of Al-based metal matrix composite is due to the formation of stable tenacious oxide film, resulting in poor wettability with the ceramic particle.…”