Synthesis, characterization and tribological behavior of electrodeposited nanostructured Co–23 wt.% Sn coatings

Abstract

Nowadays thin layers are extensively applied in a variety of technological and industrial applications, which can range from microelectronics up to transportation field. In these diverse applications, thin layers should operate under different tribological contact conditions. In this work, nanostructured Co– 23 wt.% Sn alloy electrocoatings were developed as replacements to hard chrome. However, in order to explore the potential applicability of this newly developed material, a study of the structure, mechanical and tribological properties should be performed. In addition, their tribological behavior should be studied under a wide range of contact conditions to simulate meso-load (e.g. met in MEMs and watch industry) and macro-load (e.g. met in automotive industry) contacts, as friction and wear are load dependent. For this reason, reciprocating sliding tests against an inert alumina countermaterial were performed in the mN (Hertzian contact pressure 250-560 MPa) and N (Hertzian contact pressure 470-650 MPa) load range. The aim is to illustrate that despite having similar contact pressures, different tribological phenomena can occur in these scales. Furthermore, the effect of post heat treatment was also investigated, since electrodeposition is a non-equilibrium process and structural changes might occur during heating-up.