000162289 001__ 162289 000162289 005__ 20251017144604.0 000162289 0247_ $$2doi$$a10.1007/s11249-025-02033-9 000162289 0248_ $$2sideral$$a144859 000162289 037__ $$aART-2025-144859 000162289 041__ $$aeng 000162289 100__ $$aCasasin-Garcia, M. L. 000162289 245__ $$aTungsten-Based Polyoxometalate-Ionic Liquid as Lubricant Additive for Low-Viscosity PAO: Effect of Steel Composition and Microstructure on the Boundary Lubricating Performance 000162289 260__ $$c2025 000162289 5060_ $$aAccess copy available to the general public$$fUnrestricted 000162289 5203_ $$aThe development of environmentally acceptable lubricants and lubricant additives has become a focal point within tribology due to increasing regulatory and sustainability demands. In this context, low-viscosity lubricants are gaining attention for their potential to reduce energy losses. However, their performance under a boundary lubrication regime, where thinner oil film build-up is present, requires more efficient boundary additives. This work evaluates a polyoxometalate-ionic liquid (POM-IL) as a multifunctional boundary additive in a low-viscosity polyalphaolefin-based lubricant, comparing its performance to zinc dialkyldithiophosphate (ZDDP) and a halogen-containing ionic liquid (IL). Tribological tests on AISI 316L stainless steel and AISI 52100 bearing steel revealed that while ZDDP showed substrate-independent adsorption and tribological performance, the IL-based additives had substrate-dependent behaviour. Strong chemisorption was consistent for both IL-based additives, yet their anti-wear and friction-reducing properties differed, showing evidence for the presence of a combined mechanism that includes both strong adsorption and tribochemical reactions. Additionally, the interaction between POM-ILs’ negatively charged surfaces, W atoms, and Cr(III) in 316L was identified as a key factor in their performance. Notably, significant work-hardening was observed in 316L lubricated with POM-IL-containing blends, further enhancing its anti-wear properties. These findings emphasize the role of substrate chemistry in boundary lubricant additive performance in low-viscosity lubricants, offering insights for the development of more efficient multifunctional boundary lubrication solutions. 000162289 536__ $$9info:eu-repo/grantAgreement/ES/MICINN-AEI/PRTR-C17.I1$$9info:eu-repo/grantAgreement/ES/MICINN/CEX2023-001286-S$$9info:eu-repo/grantAgreement/ES/MICINN/PID2022-141276OB-I00 000162289 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttps://creativecommons.org/licenses/by/4.0/deed.es 000162289 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000162289 700__ $$0(orcid)0000-0003-4848-414X$$aMitchell, S. G. 000162289 700__ $$aEspallargas, N. 000162289 773__ $$g73, 3 (2025), [17 pp.]$$pTribol. lett.$$tTRIBOLOGY LETTERS$$x1023-8883 000162289 8564_ $$s4539639$$uhttps://zaguan.unizar.es/record/162289/files/texto_completo.pdf$$yVersión publicada 000162289 8564_ $$s2443732$$uhttps://zaguan.unizar.es/record/162289/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000162289 909CO $$ooai:zaguan.unizar.es:162289$$particulos$$pdriver 000162289 951__ $$a2025-10-17-14:14:56 000162289 980__ $$aARTICLE