Table of Contents
ISRN Materials Science
Volume 2011, Article ID 121464, 8 pages
http://dx.doi.org/10.5402/2011/121464
Research Article

Plasma Nitriding of Surface Mo-Enriched Sintered Iron

1LABMAT, Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC, Brazil
2IF-SC, Departamento Acadêmico de Metal-Mecânica, Instituto Federal de Santa Catarina, 88020-300 Florianópolis, SC, Brazil
3UFRN, Departamento de Engenharia de Materiais, Universidade Federal do Rio Grande do Norte, Lagoa Nova Campus, 59072-970 Natal, RN, Brazil

Received 27 April 2011; Accepted 5 June 2011

Academic Editors: Y. Hiraoka and R. Rodríguez

Copyright © 2011 T. Bendo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Plain iron samples produced by powder metallurgy were submitted to a single thermal cycle involving plasma-assisted sintering and simultaneous surface alloying with Mo followed by nitriding using a plasma reactor. The microstructural characterization of the samples was carried out by optical and scanning electron microscopy in addition to X-ray diffraction. Microhardness tests were also performed. EDX line profiles of the concentration of Mo from the surface to the bulk of the sintered samples showed that the alloying element diffused down to depths of about 25 μm under the sintering conditions applied. A significant increase in microhardness was observed for samples enriched with Mo and subsequently nitrided. This behavior was attributed to the precipitation of nitrides and the presence of Mo in solid solution.