Study On Corrosion Behavior Of Aluminum Nitride Particulate Reinforced Aluminum Matrix Composite

Aluminum-matrix composites containing high volume fraction of AlN particles have been of interest for some time in many sectors of industry for their attractive thermal properties: high thermal conductivity and low coefficient of thermal expansion. It is now appreciated that the potential for this kind of composite in electronic packaging is very broad. However, the introduce of the reinforcement AlN particle affects corrosion behavior of Al/AlN_p just like other metal matrix composite,, and at the same time AlN particle easily hydrolyzes, which makes corrosion behavior of Al/AlN_p complicated. To deal with it, certain factors which influence corrosion behavior of Al/AlN_p and corrosion mechanism were systematically studied in this work. Based on it, an alkaline anodizing process for Al/AlN_p was researched, by which corrosion resistence of Al/AlN_p was effectivly enhanced.Research devoted to corrosion behavior of Al/AlN_p has been spare in comparison with research on mechanical and thermal properties. The influence of introduce of AlN particles, the pH value of the solution and hydrolysis of AlN particles on corrosion behavior of 6063/AlN_p were investigated by potentiodynamic polarization and electrochemical impandance spectroscopy (EIS) in this work. And at the same time, the general corrosion behavior of 6063/AlN_p was studied further by immersion test. The results show that the corrosion resistance for 6063/AlN_p only decreaces as the hydrolysis extent of AlN particles increases, and it is independent of introduce of AlN particles. Hydrolysis of AlN particles play different roles during the corrosion. In the initial time, hydrolysis of AlN particles makes both the pitting potential and the repassivation potential decrease, facilitating anodic reaction and cathodic reaction, which accelerates the corrosion of 6063/AlN_p. However, in the final time, hydrolysis of AlN particles helps to the formation of obstacle layer on 6063/AlN_p surface, and then accelerates the transition of corrosion mechanism from charge...