Corrosion Inhibition of Al-4.5%Cu/15ZrSiO4 Composite in HCl by LaCl2

The corrosion characteristics of Al-4.5Cu/ZrSiO4 particulate composite in 0.5molar hydrochloric acid without and with lanthanide chloride salt have been investigated. I5% ZrSiO4 was used for the production of the Al-4.5Cu/ZrSiO4 particulate composite using squeeze cast method. Addition of 15% zircon sand resulted to 5.04% decrease in density and 82.61% increase in hardness with respect to the unreinforced Al-4.5Cu matrix alloy. The time, temperature and concentration of inhibitor were varied in the range of 2-10hr, 30°C-75° and 250- 1000ppm respectively. Analysis of variance (ANOVA), factorial design and Arrhenius kinetic approach were used to explain the corrosion mechanism. All statistical design was computed at 95% confidence level. Results show that maximum inhibition was observed at 250ppm. An inhibition efficiency of 73.58% was observed after 10 hours of exposure in 0.5molar hydrochloric acid at 250ppm inhibitor concentration and 30°C. The analysis of variance and factorial design were in good agreement with the kinetic analysis.