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BIBTEX RIS

Relationship between Rheological Behaviour and Final Structure of Al 2 O 3 and YSZ Foams Produced by Replica

2012; Hindawi Publishing Corporation; Volume: 2012; Linguagem: Inglês

10.1155/2012/549508

ISSN

1687-8442

Autores

Sergio Yesid Gómez González, Óscar Álvarez, Jairo Arturo Escobar, João Batista Rodrigues Neto, Carlos R. Rambo, Dachamir Hotza,

Tópico(s)

Injection Molding Process and Properties

Resumo

Using rheological parameters of ceramic suspensions, it is possible to taylor the structure of the ceramic foams produced by replica. This method consists in the impregnation of a polymeric flexible template (polyurethane foam) with a ceramic suspension (slurry) containing the appropriate additives, followed by burning out organic compounds and additives and sintering the ceramic structure. In this work, ceramic foams were produced by the replica method from Al 2 O 3 and 3% Y 2 O 3 -ZrO 2 . Rheological parameters of the ceramic suspensions were investigated to improve the mechanical performance of final structures. Different types and quantities of raw materials were combined in order to select the formulations for ceramic foams. The parameters that have a significant influence on the process are the binder type and the amount of solids. Significant changes on the hysteresis area of the suspensions resulted in a lower density of macrodefects in the material. Likewise, when the shear rate viscosity is enhanced, the thickness of the struts increased proportionally. Lastly, when the hysteresis area magnitude and the ceramic thickness increased, the material with higher uniformity was internally densified, and the stress concentration of the internal defects was smoothed

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