Nanocrystalline diamond (NCD) coatings on high speed steel and WC-Co tools for metal forming applications
Nanocrystalline diamond (NCD) thin films show promise in tribological applications due to the excellent combination of properties like finer grain sizes, smoother surface finish, lower friction, higher hardness etc. In this study an attempt has been made to develop NCD coatings by hot filament chemical vapour deposition on standard high speed steel (HSS) substrates �and also on WC-Co metalforming tools with a view to improve the performance and life during metal forming applications. The performance of uncoated and NCD coated tool was evaluated by standard metalforming techniques like, coining, tube drawing and riveting. The deformed samples were analysed for the in homogeneity in deformation to study the tool performance and the results are discussed. The results of this study clearly established the candidature of NCD coated tool steels for metal forming applications in terms of better surface finish, higher homogeneity in deformation, greater accuracy and higher fatigue strength in the workpiece.