Self-lubricant coating systems with the release of the lubricous species have enormous potential to be used in the protection of surfaces of components working in extreme conditions of wear. However, the rapid release of the lubricious agent and, consequently, its total depletion from the coating, has delayed the transfer of these coatings to the industry, not being still an alternative to existing solutions.
This project focused on the development of a new class of thin films with the capacity to control the lubricious metal release, to get a proper long-term solid lubrication at high-temperature conditions. Nanocomposite TiSiN films composed by nanograins of TiN imbibed in a Si-N matrix was the solution proposed to control the lubricious Ag ions to reach long term lubrication. In fact, Si-N phase is well known to have anti-diffusion properties which, if proper tailored (thickness and distribution), can control the lubricious agent release.
Therefore, the project sought to explore the benefits of this nanocomposite structure with high dense interfaces as a tool to control the diffusion of silver (Ag) which the team wanted to use as a lubricious agent at high temperatures. A proposed synergy between atomistic simulations with experimental research was implemented towards the success of the work plan.
The newly developed films are expected to disrupt manufacturing by providing additional functionality, increase lifetime and reliability of components for several industries (e.g. machining, stamping, forming, automotive, aerospatial), while reducing energy consumption, CO2 emissions, maintenance and avoiding of the use of hazards lubricants, having, thus, direct impact on society and economy. Breakthroughs in simulation aspects, deposition technologies and films will expand knowledge beyond the present state of the art.
The results of this 2017 ERP are now being further exploited in the frame of the 2019 industry-driven MCTOOL 21 project | “Manufacturing of cutting tools for the 21st century: from nano-scale material design to numerical process simulation” (reference: POCI-01-0247-FEDER-045940), co-financed by the European Regional Development Fund, through Portugal 2020 (PT2020), and by the Competitiveness and Internationalization Operational Programme (COMPETE 2020).
|Title||Self lubrificant coatings for high temperature applications with controlled released of the lubricious agent|
|Funding||€ 99 571,00 plus matched funding at UT Austin|
|Leading Institution||Universidade de Coimbra (UC)|
|Participating Institutions||The University of Austin at Texas (UT Austin)
Universidade do Minho (UM)
|Begin date||November 1, 2018|
|End date||September 30, 2020|
|Keywords||Self-lubricant coatings, Ag control release,
Kinetics of Ag diffusion, Atomistic simulation of Ag ions release
- Newly self-lubricant coatings with proper control release of the lubricious phase which can provide long-term lubrication at high temperature;
- Deposition of hard and dense nanocomposite Ti-Si-N(Ag) films by high power impulse magnetron sputtering working in deep oscillation mode without the need for energetic bombardment;
- Main mechanisms governing Ag diffusion in bulk TISiN materials uncovered, with silver transport being mediated by vacancy and not interstitial defects;
- Energy barrier for Ag diffusion in Duffy-Tasker Grain boundaries as low as 0.2 eV, supporting the evidence of GBs as one main path for Ag diffusion in TiN;
- Corrected forcefield for molecular dynamics simulation of TiN: Ag-based materials.
- 10 Published papers in peer-reviewed Journals and Conferences. 1 Jointly authored (PT-US);
- 2 PhD and 2 Msc. students involved in research work;
- 6 oral communications abroad;
- 1 Strategic Research Project granted 3-year funding.
Papers and Communications
- D. Cavaleiro, S. Carvalho, A. Cavaleiro, F. Fernandes, TiSiN(Ag) films deposited by HiPIMS working in DOMS mode: Effect of Ag content on structure, mechanical properties and thermal stability, Applied Surface Science, 478 (2019) 426-434. January 2019. https://doi.org/10.1016/j.apsusc.2019.01.174
- D. Cavaleiro, A. Cavaleiro, S. Carvalho, F. Fernandes, Oxidation behaviour of TiSiN(Ag) films deposited by high power impulse magnetron sputtering, Thin Solid Films, 688 (2019) 137423. July 2019. https://doi.org/10.1016/j.tsf.2019.137423
- F. Fernandes, S. Calderon V., P.J. Ferreira, A.Cavaleiro, J.C. Oliveira, Low peak power deposition regime in HiPIMS: Deposition of hard and dense nanocomposite Ti-Si-N films by DOMS without the need of energetic bombardment, Surf. Coat. Technol., 397 (2020) 125996. https://doi.org/10.1016/j.surfcoat.2020.125996
- D. Cavaleiro, D.Veeregowda, A. Cavaleiro, S. Carvalho, F. Fernandes, High temperature tribological behaviour of TiSiN(Ag) films deposited by HiPIMS in DOMS mode, Surf. Coat. Technol, 399 (2020), 126176. https://doi.org/10.1016/j.surfcoat.2020.126176
- A. Al-Rjoub, A. Cavaleiro, F. Fernandes, Influence of Ag alloying on the morphology, structure, mechanical properties, thermal stability and oxidation resistance of multilayered TiSiN/Ti(Ag)N films, Materials & Design, 192 (2020) 108703. https://doi.org/10.1016/j.matdes.2020.108703
- F. Fernandes; A. AL-Rjoub; D. Cavaleiro; T. Polcar; A. Cavaleiro. Room and High Temperature Tribological Performance of Multilayered TiSiN/TiN and TiSiN/TiN(Ag) Coatings Deposited by Sputtering. Coatings 10 (2020) 1191. https://doi.org/10.3390/coatings10121191
- (Proceedings) International, (oral presentation) – D. Cavaleiro, S. Carvalho, F. Fernandes, Influence of Ag content on the mechanical, structural and oxidation behaviour of TiSiN(Ag) thin films deposited by HiPIMS, ICMCTF 2019, May 19-24th, San Diego, USA
- (Proceedings) International, (oral presentation) – F.Fernandes, D. Cavaleiro, S. Carvalho, A. Cavaleiro, Influence of Ag content on the high temperature tribological behavior of TiSiN(Ag) films deposited by HiPIMS, AEPSE – The 12th Asian-European International Conference on Plasma Surface Engineering, September 1-5, Jeju Island, Corea
- (Proceedings) International (INVITED presentation) – A. Cavaleiro, The use of the nanocomposite concept in hard coatings for improving the friction performance, AVS 66, Columbus, USA, October 2019
- (Proceedings) International, (oral presentation) – D. Cavaleiro, F. Fernandes, S.Carvalho, D. Veeregowda, A. Cavaleiro, High temperature tribological behaviour of TiSiN(Ag) films deposited by HiPIMS in DOMS mode, ECOTRIB 2019, Vienna, Austria, 12-14 June 2019