Fe-Cr-Ni alloy coatings were codeposited onto AISI 316L substrates using unbalanced magnetron sputtering. These were: (i) type B1, Fe-40Cr-4.5Ni; (ii) type B2, Fe-38Cr-8Ni; and (iii) type B3, Fe-55Cr-2.5Ni. In the as-deposited state, the B1 and B3 coatings mainly comprised solid solution α-Fe(Cr) and α'-Cr(Fe) phases, were fully dense, and had a microhardness of ∼700 kg ·mm-2, while coating B2 entirely comprised FeCrNi σ-phase, contained micro- or nanometre-scale porosity, and had a hardness of ∼370 kg ·mm-2. Despite being less hard, the as-deposited B2 coating displayed resistance to brittle fracture during scratch testing - this phenomenon was attributed to micropore toughening. When coating types B1 and B3 were partially or completely transformed to σ-phase (by vacuum heat treatment) brittle fracture took place during scratch testing.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Polymers and Plastics