Corrosion behavior of Al-Zn/Al_2O_3 and Al-Zn-X/Al_2O_3 (X = Cu, Mn) composites synthesized by mechanical-thermal treatment

摘要

The development of ceramic paniculate reinforced aluminum metal matrix composites (MMCs) has resulted in advanced engineering materials for potential use in structural applications in automobile and marine industries. In the present work we have analyzed the corrosion behavior of Al-Zn-Al_2O_3 MMCs with minor alloying additions of Cu and Mn. The composites have been prepared via reaction sintering of partially reacted oxide mixtures derived from a high-energy ball milling process. The influence of the high-energy ball milling on the corrosion behavior of composites in a 3.5 wt percent NaCl solution has been investigated through electrochemical experiments. The results of the corrosion tests, evaluated using the potentiodynamic method in the NaCl solution, indicate that the corrosion of the investigated composite materials depends on the weight fraction of the reinforcing particles. The polarization curves show that the milling procedure improves the corrosion resistance of the composites in the passive condition. This is illustrated by the corrosion potential, which becomes more and more noble with milling.