A method is provided for manufacturing a component. The method includes forming a diffusion coating on a first intermediate article formed by an additive manufacturing process. The diffusion coating is removed from the first intermediate article forming a second intermediate article. The diffusion coating is formed by applying a layer of coating material on at least one surface of the first intermediate article and diffusion heat treating the first intermediate article and the layer. The diffusion coating comprises a surface additive layer and a diffusion layer below the surface additive layer. The formation of the diffusion coating and removal thereof may be repeated at least once.