Corrosion and Wear Resistance of Hardmetal Coatings

摘要

There are many methods for the improvement of wear and corrosion resistance of a component, only modifying its surface. There are processes that modify the surface by changing its composition by diffusion or simply modifying the structure keeping with same composition. There are also some processes that applies a couple of layers of a new material that coats the surface and improves the properties of the substrate. Coatings can be classified in those deposited from the solid (e.g. Friction Surfacing), liquid (e.g. Thermal Spraying) or vapour (e.g. PVD, CVD) state and those deposited by reaction with the substrate. This presentation will be focused on thermal spray, that consists of a couple of techniques that are able to produce coatings for the improvement of the required properties. The basic concept of thermal spraying is to melt a feedstock material (powder, wire or rod) that is propelled by a jet zone onto a substrate. Thermal Spray Processes are able to produce coatings with nearly any material on nearly any surface and due to the fact of the large variety of processes could adapt the coating technology to the technical needs of the customer and also to his economic performance. Without any doubt, this will make Thermal Spray more competitive in comparison to other coating technologies.