Fabrication of novel ZrO2(Y2O3)–Al2O3 ceramics having high strength and toughness utilising pulsed electric current pressure sintering (PECPS). (February 2014)

• Record Type: Journal Article
• Authors: Hirota, K.; Shibaya, K.; Matsuda, H.; Kato, M.; Taguchi, H.
• Is Part Of: Advances in applied ceramics. Volume 113:Number 2(2014)
• Page Start: 73
• Page End: 79
• Publication Date: 2014-02
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1179/1743676113Y.0000000107
• Languages: English
• ISSNs: 1743-6753

Abstract

<abstract> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <sec> <p>Pulsed electric current pressure sintering (PECPS) makes it possible to produce novel monolithic and composite materials with well controlled microstructure or nanostructure, which has not been realised before. ZrO<sub>2</sub> based ceramics containing 25 mol.-%Al<sub>2</sub>O<sub>3</sub> and 0·90–1·125 mol.-%Y<sub>2</sub>O<sub>3</sub>, i.e. ZrO<sub>2</sub>(1·2–1·5 mol.-%Y<sub>2</sub>O<sub>3</sub>)–25 mol.-%Al<sub>2</sub>O<sub>3</sub>, revealing high bending strength <italic>σ</italic><sub>b</sub>≧1 GPa and high fracture toughness <italic>K</italic><sub>IC</sub> ≧15·5 MPa m<sup>1/2</sup> simultaneously, have been fabricated by PECPS of cubic ZrO<sub>2</sub> solid solution (ss) powders containing both Al<sub>2</sub>O<sub>3</sub> and Y<sub>2</sub>O<sub>3</sub> prepared via a sol–gel process. Tetragonal ZrO<sub>2</sub> (<italic>t</italic>-ZrO<sub>2</sub>) phase composite ceramics sintered at 1573 to 1623 K (1300–1350°C) for 10 min under 60 MPa in Ar were composed of ∼<italic>φ</italic>200 nm grains with high relative density ≧97·5%. Transmission electron microscopy observation cleared that these mechanical properties might originate from homogeneous distribution of <italic>α</italic>-Al<sub>2</sub>O<sub>3</sub> particles in the dense <italic>t</italic>-ZrO<sub>2</sub> matrix; the precipitation of <italic>α</italic>-Al<sub>2</sub>O<sub>3</sub> could be achieved by adopting the ss powders and PECPS.</p> </sec> </abstract>