Silver effect on the tribological and antibacterial properties of a-C:Ag coatings

• Published in: Tribology international 2019-12, Vol.140, p.105837, Article 105837
• Main Authors: Domínguez-Meister, S., Rojas, T.C., Frías, J.E., Sánchez-López, J.C.
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Coatings; Dependence; Magnetron sputtering; Nanoparticles; Polyethylenes; Rubbing; Silver; Tribology
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2019.06.030

a-C:Ag coatings (1.2–23.4 at.% of Ag) were deposited using magnetron sputtering. Ag nanoparticles appear embedded in the carbon matrix or segregated to the column boundaries or surface. The silver doping has not promoted significant changes of the sp2/sp3 ratio although a decrease of the hardness is observed (from 17 to 7 GPa). The tribological behavior did not show a clear dependence on the silver concentration in unlubricated or lubricated conditions (fetal bovinum serum) against alumina or UHMWPE balls. Ag nanoparticle dispersion enhanced the bactericide behavior as determined by the released Ag+ ion in the fluid media. There is no clear effect of friction rubbing on the released silver indicating that diffusion and top segregation are prevalent mechanisms for its dissolution. •Ag-doped (1.2–23.4 at.%) carbon films are prepared by DC-pulsed magnetron sputtering.•The tribological behavior is not compromised by the incorporation of silver.•Small Ag particles are embedded in the a-C matrix ensuring antibacterial effect.•Released Ag ions are determined in tribological tests mimicking the artificial joint.•Silver doped samples yields a significant reduction of the E. Coli bacteria growth.