• Rodrigues, Daniel
• Ortega, Fernando Dos Santos
• Janasi, Suzilene Real
• Miranda, Fábio

Abstract

<jats:p>Gelcasting has been successfully used to produce high-performance sintered ceramic components, and large shrinkages during sintering at high temperatures are common for obtaining high-density parts, since very fine ceramic powders are used as raw material. The same approach can be applied for cemented carbides (hardmetals), and near net shaped parts can be produced using moulds and, if necessary, additional turning operations before sintering can be used. Fine niobium carbide, nickel and tungsten carbide powders were used to produce aqueous slurries, which were adjusted to mold samples to obtain sintered cemented carbides with homogeneous microstructure and with a good combination of hardness and toughness. The slurry stability was investigated mainly considering the loading of solids. The nature and amounts of monomers, dispersants and additives were also investigated. Samples and prototypes were sintered at high temperature in vacuum, and characteristics such as density, microstructure and hardness were evaluated.</jats:p>

Topics

• density
• microstructure
• nickel
• carbide
• hardness
• tungsten
• sintering
• niobium