EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Rhenium Borides have been proposed as a new high hard material with high resistance to wear, cracks, and abrasion in several theoretical and experimental studies, which makes this material used as an alternative to diamond. Furthermore, rhenium borides are suitable for industrial, metallurgic, and aeronautical applications since they combine properties of metals such as high electrical conductivity and ceramics such as hardness and incompressibility. However, this material is hard to deposit because the fabrication of ReB2 coatings tends to grow non-desired phases like oxides and to delaminate because it is grown with high residual stress.

In this work, Rhenium Boride films were grown using reactive magnetron sputtering with Ti/TiN films as interlayer coating in order to enhance adherence on steel substrates. Ti/TiN bilayers were grown using a reactive atmosphere of argon and nitrogen with ratio Ar/N2=40/1.4 sccm meanwhile R.F. power, negative bias voltage, and working pressure have been fixed in the experiments to produce the ReB2. A variation on the number of bilayers of Ti/TiN showed an influence on the adherence properties of the ReB2 coatings. It was clear that the more bilayer the coating had, the better adherence it possessed.

Structural and compositional measurements were carried out using SEM, XRD, XPS to confirm the formation of ReB2 and AFM analysis to measure the thickness of the obtained films. The results are very promising as the Ti/TiN interlayer seems to significantly improve the adherence of ReB2 coatings on steel substrates.