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3781 |
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Friday, May 23, 2014, Hall H2 11:00 AM Tribological Coatings |
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New types of self-lubricated thermal spray coatings: The use of liquid lubricants in a metal matrix |
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Nuria Espallargas* / Department of Engineering Design and Materials, NTNU, Norway Sergio Armada/ SINTEF, Department of Corrosion and Tribology, Norway |
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Oils and greases are commonly used for lubricating rotating systems such as bearings, gears, connectors, etc. The maintenance of such lubricated systems in some applications where access is difficult (e.g. offshore wind farms and subsea equipment) increase the operational costs. In some cases it can be thought that the use of solid lubricants (MoS2, PTFE, graphite, etc.) embedded in coatings could be a solution for such applications however, the mechanical and dynamic conditions of most of the systems are not appropriate for solid lubricants. Despite this, solid lubricants such as PTFE and MoS2 have been largely employed in different industries, especially in those applications where liquid lubricants cannot be used and when the dynamic conditions allow for it. Self-lubricated coatings have been a major topic of interest in thermal spray in the last decades. Although the use of liquid lubricants is desirable whenever it is possible, limited research has been addressed towards the development of self-lubricated coatings containing liquid lubricants. One of the main reasons for this is due to the complexity of embedding liquid lubricant reservoirs inside the coating matrix. The production of thermal spray coatings containing liquid lubricants was first successfully achieved in 2011. The first liquid-solid self-lubricated thermal spray coating consisted of lubricant filled capsules inside a polymeric matrix. The goal of this family of coatings is to release lubricant to the system when needed. One of the challenges in producing these coatings is to prevent the degradation of the capsules containing the liquid lubricant during spraying. For this reason, the first type of liquid-solid self-lubricating coatings was produced using flame spray and a polymer matrix. In the present work, a new type of liquid-solid self-lubricated coatings is presented, being the matrix a metal alloy and the thermal spray technique used arc-spray. |