A method for improving the corrosion and fatigue crack resistance of an article (15) that has a surface (10), the method comprising the steps of : providing a dry powder (5) comprising one or more anti-corrosion materials; pressurising the dry powder to 1 to 5 MPa in an inert gas; and cold-spraying the surface (10) of the article (15) with the dry powder (5) at a particle velocity of 300 to 1200 m/s so that a corrosion and crack-resistant coating is formed on the surface of the article and the surface is modified to an average depth of 10 to 100 µm; characterised in that the surface (10) of the article (15) is pre-heated to a temperature of 50 to 900 °C, prior to cold-spraying the surface of the article with the dry powder.
