In the present investigation, the static immersion corrosion behavior of Zn/SiC, Zn/Al2O3 and Zn/Graphite metal matrix composites (MMCs) in 1 M HCl aqueous solution was studied. The aforementioned ceramic reinforcements were dispersed into the Zn matrix up to 6% (wt.-%) using conventional powder metallurgy (P/M) route. All reinforcements have average size less than 3 µm. The effect of weight percent and the reinforcement type on the corrosion behavior of Zn-MMCs was investigated. The results revealed that the corrosion rates of the Zn/Al2O3, Zn/SiC and Zn/Graphite MMCs were decreased with increasing exposure duration. While, increasing the weight percent of the ceramic particles tends to increase the corrosion rate of the fabricated MMCs. Among all investigated MMCs, the Zn/Graphite MMCs containing 2 wt.-% of graphite particulates exhibit-ed better corrosion resistance than the unreinforced Zn matrix at all exposure durations up to 96 hours. The Zn/SiC MMCs containing 4 wt.-% of SiC particulates exhibited, in most cases, lower corrosion rates than pure Zn matrix but higher than Zn/2 wt.-% Graphite MMCs. Mathematical em-pirical correlations for the corrosion rate of the MMCs in the 1 M HCl solution as a function of weight percent of reinforcements and exposure duration were developed. Such correlations can be useful in predicting the corrosion rates of the Zn MMCs with acceptable accuracies. |
