Corrosion behavior of a cerium-based conversion coating on alumina borate whisker-reinforced AA6061 composite pre-treated by hydrogen fluoride

摘要

Cerium-based conversion coatings have been made on alumina borate whisker-reinforced AA6061 composite pre-treated with hydrogen fluoride. The pre-treatment prior to coating significantly affects the microstructure and the corrosion behavior of the ultimate coated composites. The coating deposited on composite pre-treated for 20 s provides better corrosion protection than that pre-treated for 180 s. A self-healing effect is observed on the coated composite with pre-treatment for 20 s in the early stage of immersion, while no self-healing effect appears with pre-treatment for 180 s. It is largely because the morphologies of the coatings are remarkably different under the two pre-treatment conditions.