Course information

Modification of the outer-surface layers of a material, through relatively low-cost treatments, thus improving-strengthening its properties in order to utilize in high- demand applications. The purpose of the Science of Surface Technology is to guide engineers and scientists in the selection and application of surface treatments that cover a wide range of requirements. For this reason, research in the field of materials surface properties improvement has been focused in recent years in two areas: ▪ Development of surface properties (strength, hardness, optical, conductive, semi-conductive, magnetic) different from the substrate ▪ Materials properties improvement regarding their interaction with the environment (e.g. oxidation, corrosion, friction), i.e. aiming to improve the surface properties of materials, as the surface is the area of contact between the material and its environment The main categories of Surface Treatments are distinguished in: A. Modification Treatments: Modification of the surface, thus achieving changes regarding in the crystal structure, the microstructure and/or the chemical 74 composition of the surface, without depositing additional material. They strengthen the base metal itself with/or without the addition of other elements. The basic surface modification treatments are: 1. Flame Hardening 2. Induction Hardening 3. Laser Hardening 4. Electron Beam Hardening 5. Shot Peening 6. Surface Rolling 7. Carburizing 8. Nitriding 9. Boronizing 10. Nitrocarburising 11. Ion Implantation Β. Coatings: Processes with material deposition, during which a layer of another material (coating or deposition) is deposited on the surface, in order to improve the surface properties. Development of a protective, metallic or ceramic coating. The main methodologies of coatings development are: 1. Plating – Electodeposition 2. Hot Dip Coatings 3. Thermal Spray 4. Overlay 5. Physical Vapor Deposition 6. Chemical Vapor Deposition