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An XPS study of Au alloyed Al–O sputtered coatings
Figueiredo, N. M.; Carvalho, N. J. M.; Cavaleiro, A.The focus of this research is the X-ray photoelectron spectroscopy (XPS) analysis of thin films consisting of Au metal clusters embedded in a dielectric matrix of Al-O coatings. The coatings were deposited by co-sputtering an Al+Au target in a reactive atmosphere with Au contents up to 8 at.%. The Al-O matrix was kept amorphous even after annealing at 1000°C. In the as-deposited films the presence of Au cluster...
Synthesis, structural and mechanical characterization of sputtered tungsten oxi...
Parreira, N. M. G.; Carvalho, N. J. M.; Cavaleiro, A.Tungsten oxide coatings were deposited without substrate bias by DC reactive magnetron sputtering of a tungsten target using oxygen as reactive gas. By tuning the partial pressure of oxygen (pO2/pAr) between 0 and 4, the oxygen content of the films was changed from 0 to 75 at.%. The structure of the films (investigated by X-ray diffraction) depends on their oxygen content. For low oxygen contents, the [alpha]-W...
On the microstructure of tungsten disulfide films alloyed with carbon and nitrogen
Nossa, A.; Cavaleiro, A.; Carvalho, N. J. M.; Kooi, B. J.; Hosson, J. Th. M. DeThis work aimed at studying the effect of a Ti interlayer and the alloying with carbon and nitrogen of W-S-C(N) films on the mechanical and tribological properties. The W-S-C and W-S-N films were deposited by r.f. magnetron reactive sputtering with CH4 or N2 as reactive gases and analysed by high resolution electron microscopy techniques. The hardness showed an improvement with the addition of the alloying elem...
Microstructure, mechanical properties and cutting performance of superhard (Ti,...
Carvalho, S.; Ribeiro, E.; Rebouta, L.; Tavares, C.; Mendonça, J. P.; Monteiro, A. Caetano; Carvalho, N. J. M.; Hosson, J. Th. M. De; Cavaleiro, A.This paper reports on the optimization of coating properties to improve the performance of tools in severe cutting conditions. Tungsten carbide tools coated with (Ti,Si,Al)N films deposited by d.c. reactive magnetron sputtering have been investigated. The structure and the hardness of the coated samples were analyzed by X-ray diffraction (XRD) and depth-sensing indentation, respectively. XRD results revealed a ...
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