Investigation on the dynamic behaviour and corrosion characteristics of hexagonal boron nitride (h-BN) and zirconium dioxide (ZrO2) reinforced Al7075 composite

Abstract

Stir casting was used to make Al7075 composites with 3% h-BN and different amounts of ZrO2 (2%, 4%, and 6% by weight). Damping behaviour and corrosion resistance corresponding to the reinforcement percentage were investigated. Damping was evaluated using a dynamic mechanical analyzer (DMA) at varied frequencies and temperatures. Material loss due to corrosion was studied using the salt spray test for alkaline media and the immersion test for acidic media. Improvement in damping was observed with the inclusion of reinforcement in the composite. With frequencies, marginal variation in damping was observed at higher temperatures. Whereas with the increase in temperature, the damping capacity of the prepared material showed an increasing trend at all the test frequencies. The composite showed the highest value of damping capacity for 3% h-BN and 6% ZrO2 at 10 Hz and 300 °C. The corrosion resistance improved with the addition of reinforcement in both acidic and alkaline media, as the reinforcements are inert in both acidic and alkaline media. Scanning electron micrography was also performed to study the corroded surface of the specimen.

Keywords

• Al7075
• DMA
• Damping
• Composites
• SEM
• Corrosion