Ta2O5 in-situ composite Ta-based nanocrystalline coating with wonderful wear resistance and related wear mechanisms

Abstract

Tantalum (Ta)-based coating is of wide application prospects due to its remarkable physicochemical properties. In this work Ta2O5 in-situ composite Ta-based nanocrystalline coatings with superior wear resistance were successfully fabricated by plasma spraying. The study shows that the intermittently sprayed coating with less porosity and oxide content, slightly smaller grain size, a bit higher microhardness and better fracture toughness can reveal extremely low wear rate (~6.917 × 10-9 mm3/Nm). Similar Ta-based coatings with subtle microstructure differences present four distinct wear mechanisms under two typical friction conditions, among which ‘polishing’ wear mechanism is beneficial for achieving wonderful wear resistance. This work provides an insight into how the coating may be better utilized in anti-wear applications.