Comparative studies of WC-Co and WC-Co-Ni composites obtained by conventional powder metallurgy

Autor: Vinícius Martins, Wilson Corrêa Rodrigues, Peterson Luiz Ferrandini, Denis Jardim Villarinho, Gerhard Hans Knörnschild, Lírio Schaeffer
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: Materials Research, Vol 14, Iss 2, Pp 274-279 (2011)
Druh dokumentu: article
ISSN: 1516-1439
Popis: The present work reports a comparative study of cemented carbides of compositions WC-6Co, WC-10Co, WC-20Co, WC-6Co-6Ni and WC-12Ni-6Co. The purpose was to study the powder metallurgical production process of these compositions starting from a commercial WC-6Co powder, obtaining the desired compositions by mass balance with pure Co and pure Ni powders. During the process steps mixing, milling, compacting and sintering the powders were described by its apparent density, green density, shrinkage and sintered density. Lower densities were observed in composites with higher binder content. The process was monitored by scanning electron microscopy and EDS analysis to evaluate the homogeneity of the powders, to detect contaminations by the process and to characterize the microstructure of the sintered materials. A finer microstructure was found when the binder contained Ni. Potentiodynamic polarization tests in sulfuric acid revealed pseudo-passive behavior for all the tested hard metals.
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