Studies on effect of powder metallurgy on the corrosion behaviour of Al-Al₂O_3p composites

ABSTRACT

Aluminium metal matrix composites possess better mechanical and corrosion resistance properties in comparison with conventional alloys. The addition of ceramic reinforcement in the matrix material improves the corrosion resistance property of the composite. In this investigation, Al-Al₂O_3p composites were fabricated through powder metallurgy route with 5%, 10%, 15%, 20%, 25% Al₂O_3p, and the corrosion rate was evaluated with respect to the effect on volume fraction of reinforcement, the reinforcement particle size, pH and reverse potential. The corrosion test was carried out with 3.5 wt. % Sodium Chloride as a medium to analyse the corrosion behaviour of the composites. The four factors, five levels, central composite rotatable design matrix was used to conduct the optimum number of experiments. An increase in the reinforcement content decreased the corrosion rate. The rate of corrosion is more for the pH value of 1 and less for a pH value of 10. Coarse particles were found to resist corrosion, and samples with fine particles have a tendency to enhance corrosion.

KEYWORDS:

• Metal matrix composites
• corrosion
• powder metallurgy
• polarisation
• reverse potential
• central composite design

Acknowledgments

The authors are grateful to the Centre for Materials Joining and Research (CEMAJOR), Department of Manufacturing Engineering, Annamalai University for offering the required facility and guidance to proceed with this research work.

Disclosure statement

No potential conflict of interest was reported by the author(s).