Study of Atomic Layer Deposition Nano-Oxide Films on Corrosion Protection of Al-SiC Composites

In recent years, aluminum matrix composites (AMCs) have attracted attention due to their promising properties. However, the presence of ceramic particles in the aluminum matrix renders AMCs a high corrosion rate and makes it challenging to use traditional corrosion protection methods. In this study, atomic layer deposition (ALD) techniques were used to deposit HfO(2), ZrO(2), TiO(2), and Al(2)O(3) thin films on AMC reinforced with 20 vol.% SiC particles. Our results indicate that the presence of micro-cracks between the Al matrix and SiC particles leads to severe micro-crack-induced corrosion in Al-SiC composites. The ALD-deposited films effectively enhance the corrosion resistance of these composites by mitigating this micro-crack-induced corrosion. Among these four atomic-layer deposited films, the HfO(2) film exhibits the most effective reduction in the corrosion current density of Al-SiC composites in a 1.5 wt% NaCl solution from 1.27 × 10(−6) A/cm(2) to 5.89 × 10(−11) A/cm(2). The electrochemical impedance spectroscopy (EIS) investigation shows that HfO(2) deposited on Al-SiC composites has the largest R(p) value of 2.0 × 10(16). The HfO(2) film on Al-SiC composites also exhibits effective inhibition of pitting corrosion, remaining at grade 10 even after 96 h of a salt spray test.