Production of nickel matrix composites reinforced with carbide particles by granulation of fine powders and mechanical pressing

• Autor(a) principal: Nascimento, Rubens Maribondo do
• Data de Publicação: 2017
• Outros Autores: Fernandes, Maria Roseane de Pontes, Martinelli, Antonio Eduardo, Klein, Aloisio Nelmo, Hammes, Gisele, Binder, Cristiano
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/45657
• topic: Powder granulation; Nickel; Tantalum carbide; Niobium carbide; Metal matrix composite

Plain nickel and nickel composites containing either TaC or NbC powders were granulated and sintered after conventional mechanical pressing. The granulation parameters were studied using plain nickel powder to evaluate a binder system consisting of paraffin diluted in hexane, but also the suitable size range of the granules obtained. Carbide powders were then wet mixed with nickel and the powder mixtures were granulated using a drum. Flow rate tests were performed and the granules were pressed into pellets, which were dewaxed and sintered. SEM images of the microstructure of the sintered materials were obtained. Green and sintered densities along with Brinell hardness were also evaluated. The results revealed that the concentration of 1.5 wt% of paraffin and granules sieved in the range between 500 and 90 μm contributed towards the development of dense and uniform microstructures of the sintered composites. Finally, the addition of carbides homogeneously increased hardness to nearly double that of plain nickel