Regression Modeling and Experimental Investigations on Ageing Behavior of Nano-Fly Ash Reinforced Al-10wt%Mg Alloy Matrix Composites

Nano-fly ash particles reinforced Al-10wt%Mg alloy matrix composites produced by stir-casting method were tested for their ageing response. Ageing studies were performed at 160 °C, 200 °C and 240 °C temperatures and a maximum peak hardness of 142 VHN was observed during ageing at 200 °C for the composite with 10 wt% nano fly ash reinforcement. This is due to rapid nucleation and growth of βI particles at this temperature. Experiments were designed for different compositions and different ageing temperatures on the basis of the Design of Experiments technique. The factorial design is considered to improve the reliability of results and to reduce the size of experimentation without loss of accuracy. A model to predict the ageing behaviour of the composites was developed with the terms of 5, 10 and 15% weight fraction of fly ash at 160 °C, 200 °C and 240 °C ageing temperatures. The developed regression model was validated by statistical software MINITAB-R17.1.0. It was found that the developed regression model could be effectively used to predict the ageing behavior at 95% confidence level.