Investigation of mechanical properties and microstructure of al matrix composites reinforced by nano and micro mgo particles

The main objective of this research is to investigate the mechanical, microstructural and physical properties of aluminum matrix composites reinforced with nano and micro MgO particles. In this study, different mass ratios of nano and micro MgO powders with average sizes of 40 nm and 400 µm and Mg were used. Taguchi experiment design method was used and 9 different casting conditions were determined according to L9 array for nano and micro sizes of MgO particles separately. Composites were fabricated at 3 different temperatures 700oC, 800oC and 900oC by stir casting method. All samples were subjected to hardness, compression, density and porosity tests. Microstructures of composites were investigated. Microscopic observations of these composites reveal homogeneous distribution of MgO particles. According to the response tables of signal to noise ratio and ANOVA, it is observed that optimum level setting of casting parameters for compression strength of composites reinforced with nano sized MgO particles at 800oC are 1% Mg and 0.5% MgO in weight and composites reinforced with micro sized MgO particles at 800oC are 1% Mg and 1.5% MgO. Keywords: Nano particle, MgO, Stir casting, Taguchi, Aluminum matrix composite