Preparation of alumina coatings on metallic nickel substrate using a room-temperature wet chemical pretreatment method

► We have developed a new wet chemical pretreatment method for nickel surface roughening. ► The nickel substrate etched for 3 min at room temperature has a high large surface area. ► A crack-free primer coating and a slurry coating have very little tiny crack. ► This pretreatment method can obtain well-adhered alumina coating.