Wear and Corrosion Resistance of Pure Titanium Subjected to Aluminization and Coated with a Microarc Oxidation Ceramic Coating

摘要

An Al2O3 layer on hot-dip aluminized chemically pure titanium was successfully produced usingmicroarc oxidation (MAO). The thickness of the Al2O3 layer increased with the MAO duration.However, the growth rate of the Al2O3 layer reached the maximum value after approximately 20 minof MAO. Samples undergoing MAO for 20 min exhibited the highest corrosion resistance in a 3.5wt.% NaCl solution. The larger pore size on the surface of samples undergoing MAO for over 20 minaccounted for the relatively poorer corrosion resistance. The thickness and hardness of the Al2O3 layerare critical for its abrasion resistance. The wear resistance of the duplex coatings can be considerablyimproved by increasing the MAO duration, and this improvement is attributable to the increased MAOcoating thickness. In this study, the samples undergoing MAO for 40 min yielded the highest wearresistance. After subsequent diffusion annealing, cracks in the Al3Ti layer, arising from the volumeshrinkage caused by the Al3Ti formation, caused the corrosion resistance to be poor.