Adherent HFCVD diamond on steels substrates using vanadium carbide intermediate layer

• Published in: Diamond and related materials 2018-10, Vol.89, p.218-226
• Main Authors: Damm, D.D., Contin, A., Gomes, M.C.C.B., Trava-Airoldi, V.J., Barquete, D.M., Corat, E.J.
• Format: Article
• Language: English
• Subjects: Adhesion; Chemical vapor deposition; Compressive properties; Cooling effects; Diamond films; Diamond tools; Diamonds; Diffusion coating; Diffusion layers; Diffusional barrier; Field emission; HFCVD diamond growth; Organic chemistry; Protective coatings; Raman spectroscopy; Scanning electron microscopy; Stress reliever; Substrates; Tool steels; Vanadium carbide; Vanadium carbide thermodiffusion; Wear resistance; X ray spectra; X-ray diffraction
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2018.09.013

Investigations on CVD diamond deposition on steels for high performance tools development persisted over years. Literature makes out the need for an intermediate layer to improve adhesion and film quality. This work studied Thermo Diffused Vanadium Carbide (TDVC) coating deposited on AISI O1 steel by thermo reactive diffusion (TRD). Thick TDVC layers formed by varying the thermo diffusion time from 1 h to 12 h. Hot Filament Chemical Vapor Deposition reactor (HFCVD) growth conditions variation made possible diverse diamond films growth, from ultrananocrystalline to microcrystalline. X-ray diffraction, scanning electron microscopy with a field emission gun (FEG-SEM) and Raman spectroscopy were the characterization techniques used. The TDVC coating showed up as an excellent diffusional barrier and, also, a compressive stress reliever. The thicker high quality and adherent HFCVD diamond film grown over the TDVC had a thickness of 3 μm. A TDVC cross-section of 35 μm thickness could effectively mitigate diamond residual thermal compressive stress state after cooling. [Display omitted] •CVD diamond deposition over tool steel.•Increasing the TDVC coating thickness by increasing TRD process time.•TDVC coating mitigating HFCVD diamond thermal stress after cooling.•TDVC coating as excellent diffusional barrier against to iron and carbon migrations.•HFCVD diamond high quality and adhesion.