New Routes in the Preparation of Mechanically Hard Films

TLDR

Superhard nitride superlattice coatings with nanometer‑scale multilayers exhibit hardnesses above 50 GPa and can be economically deposited by reactive sputtering on diverse substrates, benefiting from recent advances in pulsed dc power and reactive‑gas control. The study aims to develop oxide superlattice films by applying the superlattice strength model together with advanced reactive sputtering technology. Oxide superlattice films are fabricated using pulsed dc reactive sputtering with precise gas‑partial‑pressure control, guided by the strength‑prediction model to select compatible material combinations. The developed strength‑prediction model accurately forecasts which material pairs yield enhanced hardness in superlattice films.

Abstract

Superhard nitride superlattice coatings with nanometer-scale multilayers have hardnesses exceeding 50 gigapascals, making these films highly resistant to abrasion. The nitride superlattice films can be deposited economically by reactive sputtering in production-size equipment on a variety of substrates. A model for the superlattice strength enhancement has been developed that accurately predicts which materials can be used together to produce the enhanced hardness. Advancements in sputtering technology-specifically, pulsed dc power and reactive-gas partial-pressure control-make it possible to reactively deposit nonconducting oxide films at high deposition rates. This technology is being used along with the superlattice strength model in the development of oxide superlattice films.