Influence of Substrate Properties on the Impact Resistance of WC Cermet Coatings

Abstract

Abstract This research delivers an integrated performance of generic coating-substrate systems under impact loading, and comprehends the understanding of underpinning failure mechanisms. This investigation thus benchmarks the coating design process for high impact stress applications. Repeated severe impacts to the coatings often result in poor performance by cracking and delamination from the coating-substrate interface. The durability and delamination resistance of coatings depend on the choice of coating and substrate materials, coating deposition process and service conditions. The design of overlay thermal spray coatings thus requires an optimization of these parameters. A thorough understanding of the underpinning failure mechanisms is thus critical for future coating developments. This investigation thus provides an insight to the role coating and substrate properties on the impact resistance of coated materials, and maps the relationship between the impact resistance of WC-Co and WC-CrC-Ni coatings on a variety of substrates. Results indicate that coating’s delamination resistance during impact loading not only depends upon the hardness and roughness of the substrate material, but more importantly, substrates with higher work-hardening coefficient indicate a higher delamination resistance during impact loading.