23 research outputs found
Contribution to the study of the Fe-Nb-C ternary system
In the present paper, solidification sequences are proposed in relation to the observed microstructures for Fe-Nb-C iron based ternary alloys. These alloys are arc melted and characterised by means of differential thermal analysis, scanning electronic microscopy and by quantitative electron probe microanalysis. Thus, an invariant eutectic ternary reaction L + NbC + FeC is proposed at 1140°C.Dans cet article, les séquences de solidification sont proposes en relation avec les microstructures observées pour une famille d’alliages ternaires base fer Fe-Nb-C. Ces alliages ont été élaborés dans un four à arc et caractérisés par Analyse Thermique Différentielle, Microscopie Electronique à Balayage et Microsonde Electronique. Ainsi, une réaction invariante ternaire
L + NbC + FeC est proposée à 1140 °C
Effect of the Plasma Deposition Parameters on the Properties of Ti/TiC Multilayers for Hard Coatings Applications
Titanium carbide (TiC) hard coatings have been obtained on steel and silicon substrates by rf magnetron sputtering process. Two layer coatings have been deposited in order to improve adhesion on steel. The lower layer was titanium metal and the upper TiC layer was obtained by reactive sputtering of the titanium target in Ar and methane gas mixture. The study confirmed that the TiC layer composition depends on the reactive sputtering gas composition and substrate bias voltage. Film microhardness was measured by microindentation. Measurement results showed that the hardness coating depends on the microstructure of our coatings and the polarization of bias substrate is an important parameter to control the microstructure