resumo
The effect of composition in the formation of carbides in the WC-M (M = Fe/Ni/Cr) system has been studied. Three conventional compositions have been prepared with 10 wt.% of metallic binder. Fe as a metallic binder was first studied and its partial substitution by Ni and Cr was also investigated. A WC powder coated with a similar binder (Fe/Ni/Cr) amount was also investigated. The XRD results, after thermal treatment at 1400 degrees C, reveal that the substitution of half percent of the iron content by Ni stabilized the austenite Fe(gamma) formation. The introduction of Cr in the binder composition induces the formation of Cr(2)C carbide. With the decrease of Cr amount in the binder composition of the coated powder, Cr(2)C carbide was not formed, but instead other carbide, M(6)C, was detected. In order to eliminate this carbide a small excess of carbon (3.6 wt.%) was added to the coated powder. The results are discussed in terms of the phases formed, the binder composition and the final carbon content. (C) 2007 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
palavras-chave
CEMENTED CARBIDES; STAINLESS-STEEL; HARDMETALS; PARTICLES; POWDERS; BINDER
categoria
Materials Science
autores
Femandes, CM; Popovich, V; Matos, M; Senos, AMR; Vieira, MT
nossos autores
Ana Maria de Oliveira e Rocha Senos
Colaborador
Cristina Maria da Silva Fernandes
ColaboradorGrupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
agradecimentos
The author C.M. Fernandes gratefully acknowledges the financial support of the POCTI programme of the Portuguese Foundation for Science and Technology (FCT) and European Social Fund (FSE).