Study and characterization of a metal matrix composite reinforced with tantalum carbide-TaC

• Autor(a) principal: Oliveira, Leiliane Alves de
• Data de Publicação: 2015
• Outros Autores: Gomes, Uílame Umbelino, Souza, Carlson Pereira, Soares, Sérgio Renato da Silva
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/32589
• topic: EUROFER97; TaC; Powder Metallurgy; MMC

Steel is an alloy EUROFER promising for use in nuclear reactors, or in applications where the material is subjected to temperatures up to 550°C due to their lower creep resistance under. One way to increase this property, so that the steel work at higher temperatures it is necessary to prevent sliding of its grain boundaries. Factors that influence this slip contours are the morphology of the grains, the angle and speed of the grain boundaries. This speed can be decreased in the presence of a dispersed phase in the material, provided it is fine and homogeneously distributed. In this context, this paper presents the development of a new material metal matrix composite (MMC) which has as starting materials as stainless steel EUROFER 97, and two different kinds of tantalum carbide-TaC, one with average crystallite sizes 13.78 nm synthesized in UFRN and another with 40.66 nm supplied by Aldrich. In order to improve the mechanical properties of metal matrix was added by powder metallurgy, nano-sized particles of the two types of TaC. This paper discusses the effect of dispersion of carbides in the microstructure of sintered parts. Pure steel powders with the addition of 3% TaC UFRN and 3% TaC commercial respectively were ground for 5 hours in the planetary mill. Each of the resultant particulate samples were cold compacted under a uniaxial pressure of 600MPa in a cylindrical die 5 mm in diameter. Subsequently, the compressed were sintered in a vacuum oven at a temperature of 1250°C with an increment of 20°C and 10°C per minute and maintained at these isotherms for 60 minutes. The distribution, size and dispersion of steel and composite particles were determined by X-ray diffraction, laser particle size and scanning electron microscopy(SEM). The structures of the sintered bodies were observed by optical microscopy(OM) and scanning electron microscopy(SEM)