CORROSION SUSCEPTIBILITY OF AA5083-H116 IN BIOLOGICALLY ACTIVE ATMOSPHERIC MARINE ENVIRONMENTS

摘要

Aluminum alloy (AA) 5083-H116 was exposed to laboratory marine atmospheres with and without fungi. AA5083-H116 coupons were half covered with potato dextrose agar (PDA), a fungal growth media; the remaining coupon areas were left bare and fully exposed to the marine atmosphere. Fungal mycelia were inoculated into the PDA and grew over the entire coupon surface during the 90-day exposure. Overlaid with PDA, AA5083-H116 exhibited shallow crystallographic etching and grain boundary attack. Fungi increased the likelihood and severity of pitting corrosion when compared with abiotic controls. Fungal mycelia were associated with trenching and intergranular pits on the bare surfaces. Al-Si-Mg particles were associated with small (10 nm) pits over the entire coupon surface, regardless of exposure condition.