STP1532

    CVD of Alternated MCD and NCD Films on Cemented Carbide Inserts

    Published: Apr 2012


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    Abstract

    Chemical vapor deposition (CVD) diamond coating of cemented carbide cutting tools has been an alternative to increase tool-life. Experiments have shown that residual stresses produced during films growth on cemented carbide inserts significantly increases with increasing film thickness of up to 20 μm and usually leads to film delamination. In this work alternated micro- and nanocrystalline CVD diamond films have been used to relax interface stresses and to increase diamond coatings performance. Cemented carbide inserts have been submitted to a boronizing thermal diffusion treatment prior to CVD diamond films growth. After reactive heat treatment samples were submitted to subsequently chemical etching in acid and alkaline solution. The diamond films deposition was performed using hot-filament chemical vapor deposition (HFCVD) reactor with different gas concentrations for microcrystalline diamond (MCD) and nanocrystalline diamond (NCD) films growth. As a result, we present the improvement of diamond films adherence on cemented carbide inserts, evaluated by indentation and machining tests. Samples were characterized by scanning electron microscopy and energy dispersive X ray for qualitative analysis of diamond films. X-ray diffraction was used for phases identification after boronizing process. Diamond film compressive residual stresses were analyzed by Raman scattering spectroscopy.

    Keywords:

    cutting tools, HFCVD, diamond films, thermal diffusion


    Author Information:

    Campos, Raonei Alves
    Instituto Nacional de Pesquisas Espaciais–INPE, Av. dos Astronautas, São Paulo,

    Contin, Andre
    Instituto Nacional de Pesquisas Espaciais–INPE, Av. dos Astronautas, São Paulo,

    Trava-Airoldi, Vladimir Jesus
    Instituto Nacional de Pesquisas Espaciais-INPE, Av. dos Astronautas, São Paulo,

    Barquete, Danilo Maciel
    Universidade Estadual de Santa Cruz–UESC, Bahia,

    Corat, Evaldo José
    Instituto Nacional de Pesquisas Espaciais-INPE, Av. dos Astronautas, São Paulo,


    Paper ID: STP153220120026

    Committee/Subcommittee: D02.L0

    DOI: 10.1520/STP153220120026


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