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Project Name
Self lubrificant coatings for high temperature applications with controlled released of the lubricious agent




Albano Carvalho
Principal Investigator
in Portugal




Yuanyue Liu
Principal Investigator
in Austin

Self-lubricant coatings
Ag control release
Kinetics of Ag diffusion
Atomistic simulation of Ag ions release

Self-lubricant coating systems able to control the release of lubricious species during operation have enormous potential to protect components working in extreme conditions combining high temperature and contact pressure. Until now, high temperatures result in strong diffusion, leading to the rapid depletion of the lubricious agent and the inoperability of the component. On this basis, TiSiN coatings were deposited using an emergent technology (HiPIMS-high power impulse magnetron sputtering), which allows the formation, at room temperature, of nanocomposite structures consisting of a quasi-amorphous Si-N-matrix-separated TiN nanograins. This is the key design this proposal will explore to control the outer-diffusion of the lubricious agent, in this case silver,in a new radical approach of self-lubricant coatings for high temperature applications. SI-N phase is well known to have anti- diffusion properties which,If proper tailored (thickness and distribution),can control the lubricious agent release. The low temperature deposition will allow Ag to be adequately dispersed on the nanocomposite structure either in metastable solid solution in TiN lattice or nanoparticles with different sizes in interface sites, without being continuously segregated during the deposition process. The morphology and structure of the films will be optimized for either anti-diffusion properties, by controlling the thickness of the Si-N layer,or the Ag incorporation as solid solution or as nanoparticles with different sizes and distribution. To understand the diffusion mechanisms, advanced characterization methods will be used to characterize the coatings, such as, high-resolution SEM and TEM analysis coupled to EDS, in-situ high-temperature TEM experiments and in-depth chemical composition evaluation by depth profiling XPS.

Leading Institution
Universidade de Coimbra (UC)

Participating Institutions
Universidade do Minho (UM)

12 months