Applications of Energetic Particles in Improving Coating Adhesion Properties

Conference · Wed Nov 07 00:00:00 EST 1990

OSTI ID:6076731

Fenske, George R. ^[1]

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1. Argonne National Laboratory (ANL), Argonne, IL (United States)

In many engineering situations, material selection is often based on a compromise of bulk-mechanical properties and near-surface properties, with neither set of properties at its optimum value. Often the material of choice (e.g., high-Cr steel in corrosion applications, or TiN or WC in wear applications) cannot be fabricated into bulk components due to limitations based on cost, fabrication, and mechanical properties. In such cases, various processes are available to deposit coatings of the desired material on components fabricated from materials with desirable bulk properties. A key property of any coating process is adhesion of the coating to the substrate. Without adequate adhesion, the coating will be lost and thus can no longer be protect the substrate. Numerous surface-modification processes can be used to modify the surface properties of a wide range of materials. These processes range from surface heat treatments (e.g., thermal hardening, carburizing, nitriding, carbonitriding, boriding, and metalliding) that rely on thermal processes (primarily diffusion) to produce the desired property in near-surface regions, to surface coating processes (e.g., electro- and electroless-chemical deposition, chemical vapor deposition [CVD], physical vapor deposition [PVD], spraying processes, and welding processes) in which material is formed or deposited on the surface. Adhesion is usually not a major concern with surface heat treatments because thermal diffusion produces a gradual change in composition. In surface coating treatments, however, the transition from the bulk material to the coating material is much more abrupt and thus adhesion is a very important factor that must be addressed in selecting the deposition process. This paper addresses one approach (on-beam-assisted deposition, or IBAD) that utilizes energetic ion beams to enhance the adhesion of metallic films to metallic and ceramic substrates. In one application, IBAD is used to improve the adhesion of silver films to ceramic substrates that are subjected to sliding wear conditions at elevated temperatures. In another application, the IBAD process is used to improve the adhesion and modify the microstructure of chromium films deposited on low-Cr steel. Both applications suggest that adhesion can be increased by a number of mechanisms including (a) physical and chemical sputtering of surface contaminants (e.g., hydrocarbons and adsorbed water molecules); (b) preferential sputtering of a particular element of a compound, thus producing a surface enriched in a species that is chemically active with the depositing species; (c) activating chemical states; (d) mechanically roughening the surface, producing more surface area for bonding and sites to arrest surface cracks; and (e) recoil-mixing during the initial stage of film deposition.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6076731
• Report Number(s): ANL/CP-72530; CONF-9011183-1; ON: DE91008833
• Resource Relation: Conference: Potential Applications of Concentrated Solar Photons Workshop , Golden, CO (United States), 7-8 Nov 1990
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHROMIUM
ENERGY BEAM DEPOSITION
METALS
SILVER
ADHESION
ALUMINIUM OXIDES
CERAMICS
CHEMICAL VAPOR DEPOSITION
ION BEAMS
PHOTON BEAMS
SOLAR RADIATION
SPUTTERING
SUBSTRATES
SURFACE CLEANING
SURFACE PROPERTIES
SURFACE TREATMENTS
ZIRCONIUM OXIDES
ALUMINIUM COMPOUNDS
BEAMS
CHALCOGENIDES
CHEMICAL COATING
CLEANING
DEPOSITION
ELEMENTS
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
STELLAR RADIATION
SURFACE COATING
SURFACE FINISHING
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
ZIRCONIUM COMPOUNDS
360101* - Metals & Alloys- Preparation & Fabrication