Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...
Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...
Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...
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JUNE 28 WEDNESDAY AFTERNOON<br />
JS2-WeA-P3 CARBIDES FORMATION IN TANTALUM THIN LAYERS DEPOS-<br />
ITED ON STEEL SUBSTRATES. Y. Hadjar. Institut de Tronc Commun Sciences Exactes et<br />
Technologie, Université de Batna, Algérie, R. Halimi, Laboratoire Couches Minces et Interfaces,<br />
Université Mentouri, 25000 Constantine, Algérie.<br />
In the present work we are intending to elaborate and to study thin film coating of tantalum carbides<br />
on steel substrates. The procedure used in order to prepare the samples consist on depositing, by<br />
electron gun evaporation, a thin film (4µm thickness) of tantalum on steel substrates containing 1<br />
%wt. of carbon, then, annealing the system (substrate/coating) in vacuum at a temperature at which<br />
the carbon of the substrate may diffuse into the Ta metallic film. This fact leads to the formation of<br />
tantalum carbides. The effects of the annealing on the kinetic of tantalum carbides formation and<br />
morphology have been investigated using X- ray diffraction (XRD), secondary ion mass spectroscopy<br />
(SIMS) and scanning electron microscopy (SEM). The mechanical characterization was performed<br />
by measuring microhardness and adhesion. It is found that at annealing up to 800°C the<br />
compounds Ta 2 C and TaC are formed. During the subsequent heat treatment from 900°C to 1100°C<br />
the final TaC phase grows at the expense of the Ta2C phase. Moreover, the microhardness and adhesion<br />
of the films increase significantly with increasing annealing temperature. At a given temperature,<br />
the microhardness increases, with the rise of the annealing time, to reach a maximum and then<br />
decreases. The final coating layer has a golden color and presents a columnar structure. The formation<br />
mechanisms are discussed.<br />
Key words: hard coatings, tantalum carbides, thin films, diffusion.<br />
Presenting author: R. HALIMI<br />
E-mail: rachid_halimi@yahoo.fr<br />
Presentation type: Poster<br />
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