Glancing angle intermediate layer deposition approach for CVD diamond coating of high-speed steel substrates

Abstract

This work demonstrates a new approach to the synthesis of highly adhesive diamond coatings on high-speed steel (HSS) substrates using a glancing angle deposition (GLAD) technique. The parameters of deposition of a molybdenum intermediate layer with a high level of surface roughness at a minimum layer thickness are determined. A maximum roughness of 38.1 nm with a minimum Mo layer thickness of 2 μm was achieved at an incidence angle of 15° and three sample positions. The duration of Mo sputtering at each rotation was 15, 10, 30 min. It is shown that a 2 μm Mo interlayer deposited by GLAD technique increases microcrystalline diamond film adhesion to HSS substrate compared to normally deposited Mo interlayer of the same thickness. The average delimitation area of the diamond film synthesized on a normally deposited molybdenum layer exceeds the corresponding parameter for the coating synthesized on the GLAD Mo layer by more than 8 times. Additionally, the process of diamond-Mo interlayer mechanical interlocking is also considered.