Preparation of aluminide coatings on the inner surface of tubes by heat treatment of Al coatings electrodeposited from an ionic liquid

摘要

Aluminide coatings were prepared on the inner surface of 316L stainless steel tubes with size of 0 12 mm x 1000mm by heat-treating Al coatings electrodeposited from AlCl3-1-ethyl-3-methylimidazolium chloride (AlCl3-EMIC) ionic liquid at room temperature. Studies on the electrolytic etching pretreatment of stainless tubes before Al coating electrodeposition were carried out. The Al coating showed good adherence to the substrate after electrolytic etching at 10 mA/cm(2) for 10 min. The thickness of Al coatings was uniform along the tube. The structure of prepared aluminide coatings can be regulated by different thickness of Al coating. The outer layer of aluminide coatings was FeAl, Fe2Al5 and FeAl3 for the samples of 1-mu m, 5-mu m and 10-mu m thick Al coatings, respectively. (C) 2015 Elsevier B.V. All rights reserved.