A modified gel casting procedure based on a natural gelatin for food industry and commercial polyethylene spheres as pore formers was successfully exploited to produce dense and porous ceramic bodies made of yttria stabilized tetragonal zirconia polycrystal (Y-TZP). Vickers and Knoop microhardness, elastic modulus and fracture toughness measurements on dense samples obtained by experimental investigation closely matched results found in the literature for similar materials. However, after a careful analysis of obtained results, no indentation size effect and a lower scattering of experimental data from low load indentations were observed, in comparison with literature. Mechanical testing of porous samples (with reproducible values of porosity of about 40%) evidenced a high scattering of compressive strength values, suggesting that the uneven distribution of cavities in the material or the presence of defects from the agglomeration of pore forming agents could have a more direct influence on the mechanical properties of such materials than the absolute value of porosity. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Preparation and mechanical characterization of dense and porous zirconia produced by gel casting with gelatin as a gelling agent / Jean Marc, Tulliani; Bartuli, Cecilia; Edoardo, Bemporad; Valentina, Naglieri; Marco, Sebastiani. - In: CERAMICS INTERNATIONAL. - ISSN 0272-8842. - STAMPA. - 35:6(2009), pp. 2481-2491. [10.1016/j.ceramint.2009.02.017]
Preparation and mechanical characterization of dense and porous zirconia produced by gel casting with gelatin as a gelling agent
BARTULI, Cecilia;
2009
Abstract
A modified gel casting procedure based on a natural gelatin for food industry and commercial polyethylene spheres as pore formers was successfully exploited to produce dense and porous ceramic bodies made of yttria stabilized tetragonal zirconia polycrystal (Y-TZP). Vickers and Knoop microhardness, elastic modulus and fracture toughness measurements on dense samples obtained by experimental investigation closely matched results found in the literature for similar materials. However, after a careful analysis of obtained results, no indentation size effect and a lower scattering of experimental data from low load indentations were observed, in comparison with literature. Mechanical testing of porous samples (with reproducible values of porosity of about 40%) evidenced a high scattering of compressive strength values, suggesting that the uneven distribution of cavities in the material or the presence of defects from the agglomeration of pore forming agents could have a more direct influence on the mechanical properties of such materials than the absolute value of porosity. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
