Synergic effect of TMD coating on textured steel using micro-EDM

Abstract

Modifying the surface of materials through texturing and coating can have a significant impact on their tribological properties. In the present study, a hybrid surface modification process, texturing combined with coating, has been applied to a steel surface and the tribological behavior in lubricated conditions was studied. The surface of the steel was textured using micro-electric discharge machining (micro-EDM) to create two distinct patterns (rectangular and circular). Following this, transition metal dichalcogenides (TMD); tungsten-sulphur‑carbon (WSC) coating was applied to the surface using magnetron sputtering. To evaluate the specimens, they were subjected to tribological testing in various lubrication conditions using a block-on-ring configuration. The results were corroborated using a reciprocating sliding test and compared to those of a smooth uncoated specimen. The findings revealed that the tribological properties of the textured and coated specimens were enhanced, particularly in specimens with circular dimple patterns. The WSC coated circular dimple specimens showed a reduction of the COF by 7–12 %, in the boundary lubrication regime and by 9–25 %, in the mixed and hydrodynamic lubrication regimes as compared to the untreated specimen.The authors record sincere thanks to the University of Minho, Instituto Pedro Nunes and CEMMPRE for extending its facilities. This work is sponsored by FEDER and by National funds through FCT- Fundação para a Ciência e a Tecnologia under the projects: ON-SURF ref. “POCI-01- 0247-FEDER-024521”, ATRITO-0 ref. “POCI-01-0145-FEDER-030446”, CEMMPRE ref. “UIDB/00285/2020” and ARISE ref. “LA/P/0112/ 2020”