Diamond film adhesion onto sub-micrometric WC-Co substrates

► Sub-micrometric hardmetal grades coated by HFCVD with microcrystalline diamond films. ► Two-step Murakami/Aqua regia attack for proper surface roughness and Co removal. ► Higher Co content favours diamond seeding and film anchoring at the interface. ► Interfacial crack resistance of 1.6 kgf/μm reveals high adhesion level.