Influence of Powder Porous Structure on the Deposition Behavior of Cold-Sprayed WC-12Co Coatings

• Published in: Journal of thermal spray technology Vol. 17; no. 5-6; pp. 742 - 749
• Main Authors: Gao, Pei-Hu, Li, Yi-Gong, Li, Chang-Jiu, Yang, Guan-Jun, Li, Cheng-Xin
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.12.2008; Springer Nature B.V
• Subjects: Analytical Chemistry; Cemented carbides; Cermets; Characterization and Evaluation of Materials; Chemistry and Materials Science; Coatings; Cobalt; Cold spraying; Corrosion and Coatings; Deposition; Hardness; Machines; Manufacturing; Materials Science; Peer Reviewed; Porosity; Processes; Sprayers; Spraying; Sprays; Surfaces and Interfaces; Thin Films; Tribology; Tungsten carbide; hardness; porous structure; WC-12Co; cold spraying; deposition behavior
• ISSN: 1059-9630; 1544-1016
• DOI: 10.1007/s11666-008-9258-1

The limited deformation of hard cermet particles and impacted coating makes it difficult for conventional thermal spray powders to continuously build up on impact in cold spraying. In this study, three nanostructured WC-12Co powders with different porous structure and apparent hardness were employed to deposit WC-Co coatings on stainless steel substrate by cold spraying. The deposition characteristics of three powders of porosity from 44 to 5% were investigated. It was found that WC-Co coating is easily built-up using porous powders with WC particles bonded loosely and a low hardness. The microhardness of WC-12Co coatings varied from 400 to 1790 Hv with powders and spray conditions, which depends on the densification effects by impacting particles. With porous WC-Co powders, the fracture of particles on impact may occur and low deposition efficiency during cold spraying. The successful building up of coating at high deposition efficiency depends on the design of powder porous structure.