TU Darmstadt / ULB / TUbiblio

The influence of post-sintering HIP on the microstructure, hardness, and indentation fracture toughness of polymer-derived Al2O3–SiC nanocomposites

Galusek, Dušan ; Sedláček, Jaroslav ; Švančárek, Peter ; Riedel, Ralf ; Satet, Raphaelle ; Hoffmann, Michael (2007):
The influence of post-sintering HIP on the microstructure, hardness, and indentation fracture toughness of polymer-derived Al2O3–SiC nanocomposites.
In: Journal of the European Ceramic Society, 27 (2-3), pp. 1237-1245. SciVerse, ISSN 09552219,
[Article]

Abstract

Al2O3–SiC nanocomposites containing 3–8 vol.% SiC were prepared from fine α-alumina powder and a poly(allyl)carbosilane precursor of SiC by polymer infiltration of porous alumina matrix (composites IP), or by warm pressing of polymer-coated alumina powder (composites CW). The polymer was converted to SiC by careful heating of green specimens in inert atmosphere (Ar). The residual porosity was eliminated to less than 10% by pressureless sintering (PS) at temperatures between 1700 and 1850 °C. The post-sintering hot isostatic pressing (HIP) at 1700 °C eliminated the residual porosity to less than 1%, but also resulted in coarsening of the alumina matrix grains, and the inter- and intragranular SiC inclusions. The Vickers hardness of IP specimens sintered at T < 1850 °C increased by 1–10%, which is attributed to elimination of residual porosity. The hardness and indentation fracture toughness of specimens IP sintered at 1850 °C decreased after HIP by 6 and 15%, respectively. The HIP of CW composites increased their hardness and fracture toughness by approximately 10%. The maximum fracture toughness of 5.2 ± 0.2 MPa m1/2 was measured for the materials containing 8 vol.% of SiC. A correlation was found between the fracture toughness, and the mean size and volume fraction of intergranular SiC inclusions in composites CW.

Item Type: Article
Erschienen: 2007
Creators: Galusek, Dušan ; Sedláček, Jaroslav ; Švančárek, Peter ; Riedel, Ralf ; Satet, Raphaelle ; Hoffmann, Michael
Title: The influence of post-sintering HIP on the microstructure, hardness, and indentation fracture toughness of polymer-derived Al2O3–SiC nanocomposites
Language: English
Abstract:

Al2O3–SiC nanocomposites containing 3–8 vol.% SiC were prepared from fine α-alumina powder and a poly(allyl)carbosilane precursor of SiC by polymer infiltration of porous alumina matrix (composites IP), or by warm pressing of polymer-coated alumina powder (composites CW). The polymer was converted to SiC by careful heating of green specimens in inert atmosphere (Ar). The residual porosity was eliminated to less than 10% by pressureless sintering (PS) at temperatures between 1700 and 1850 °C. The post-sintering hot isostatic pressing (HIP) at 1700 °C eliminated the residual porosity to less than 1%, but also resulted in coarsening of the alumina matrix grains, and the inter- and intragranular SiC inclusions. The Vickers hardness of IP specimens sintered at T < 1850 °C increased by 1–10%, which is attributed to elimination of residual porosity. The hardness and indentation fracture toughness of specimens IP sintered at 1850 °C decreased after HIP by 6 and 15%, respectively. The HIP of CW composites increased their hardness and fracture toughness by approximately 10%. The maximum fracture toughness of 5.2 ± 0.2 MPa m1/2 was measured for the materials containing 8 vol.% of SiC. A correlation was found between the fracture toughness, and the mean size and volume fraction of intergranular SiC inclusions in composites CW.

Journal or Publication Title: Journal of the European Ceramic Society
Journal volume: 27
Number: 2-3
Publisher: SciVerse
Uncontrolled Keywords: Hot isostatic pressing, Precursors-organic, Microstructure-final, Mechanical properties, Al2O3–SiC
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Dispersive Solids
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences
Date Deposited: 17 Apr 2012 09:32
Official URL: http://dx.doi.org/10.1016/j.jeurceramsoc.2006.04.028
Identification Number: doi:10.1016/j.jeurceramsoc.2006.04.028
Funders: The financial support of this work by the Alexander von Humboldt Foundation, Bonn, Germany, by the grant number O051/03R80600/03R0603, and by the Slovak National Grant Agency VEGA, under the contract number 2/3101/23, is gratefully acknowledged.
Export:
Suche nach Titel in: TUfind oder in Google
Send an inquiry Send an inquiry

Options (only for editors)
Show editorial Details Show editorial Details