Evaluation of Mechanical and Microstructure Properties of Mg-Modified Aluminum Matrix Composite by Vortical Casting Method

In this study, the vortical casting used to increase the wettability of ceramic particles, which is an obstacle to achieving a uniform distribution of reinforcing particles in the matrix. The effect of magnesium modifier on the mechanical properties, fracture mechanism, porosity, and surface morphology of A356 aluminum matrix composite reinforced with nano-alumina-micro-copper reinforcing particles investigated. Alumina nanoparticles and copper microparticles milled, and the resulting powder mixture was added to the aluminum melt in a vortical casting process to produce A356/1.5 vol% nano Al2O3/Cu composite and subsequently various amounts of magnesium added to the melt. The results of this study showed that with the addition of reinforcing nanoparticles as well as magnesium, the porosity increased, the highest amount of which in composite containing 10% volume of magnesium equals 2.8%. The optimum amount of magnesium that made the composite structure uniform was 7%. Also, the addition of magnesium reduced the hardness oscillations throughout the sample, and the highest hardness reported to be 141.2. The presence of a 7% volume of magnesium in the composite showed the ultimate strength of 190.2 and yield strength of 130.3. Finally, according to the results, the composite fracture mechanism was controlled by the fracture of the interface between the reinforcing particles and the matrix. Graphic

Automated summary

The study utilized vortical casting to enhance the wettability of ceramic particles and investigated the effect of magnesium modifier on the properties of A356 aluminum matrix composite reinforced with nano-alumina-micro-copper reinforcing particles. The addition of 7% volume of magnesium was found to produce a composite with uniform structure and good strength.