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The diamond thin films chemical vapor deposition (CVD) on sintered tungsten carbide (WC-Co) tools shows increasing interest in the technological research, due to rapid growing utilization of aluminum alloys, like Al-Si alloys, in the automotive industry. Sintered carbides, mainly diamond coated sintered carbides, are very suitable to machine aluminum alloys. The cobalt binder that accounts for the WC-Co substrate toughness degrades the interface film-substrate, catalyzing the formation of graphite preferentially to diamond during the deposition process. In addition, stresses are generated in the interface between WC-Co substrate and deposited diamond film due to thermal expansion mismatch. These two factors are a technological neck to large-scale production of diamond CVD coatings for machining tools. In this work, several interface pre-treatments were developed and applied resulting in high film-substrate adherence, adequate for machining tool purposes.

The automotive industry has identified several automobile components that could be replaced with titanium alloy components, either through direct replacement in existing designs or, preferably, in new designs to fully exploit the unique properties of titanium. The alloy processing by powder metallurgy (M/P) eases the obtainment of parts with complex geometry and, probably, cheaper. In this work, results of the Ti-35Zr-10Nb alloy production are presented. This alloy due to its high wear, impact and corrosion resistance is a promising candidate for automotive applications. Samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering between 900-1400 °C, in vacuum. Sintering behavior was studied by means of dilatometry. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively.

CVD diamond film deposition on WC-Co substrate is the most likely application of diamond CVD technology towards large scale production, due to its suitability to aluminium alloys machining in the automotive and aerospace industry. Several film-substrate interfaces and surface modifications have been developed aiming higher levels of simultaneous diamond film-substrate adherence and substrate surface toughness, however the results are still far bellow industry requirements for widen scale application. In this work a new interface is introduced in the CVD diamond films technology, which consists of a thermo-reactive deposited and diffused vanadium carbide layer, highly adequate to diamond films deposition on cemented carbide cutting and forming tools. This interface presents good diamond growth characteristics, thermal expansion coefficient similar to the substrate and, in addition, high hardness and mechanical strength.