Availableonlineatwww.sciencedirect.com Science Direct E噩≈RS ELSEVIER Joumal of the European Ceramic Society 29(2009)1631-1639 www.elsevier.com/locate/jeurceramsoc Development and characterisation of high-density oxide fibre-reinforced oxide ceramic matrix composites with improved mechanical properties C Kaya.*, F. Kaya, E.G. Butler, A.R. Boccaccini d, KKChawla a yildiz Technical University, Faculty of Chemistry and Metallurgy, Department of Metallurgical and Materials Engineering, avutpasa Campus, Esenler, L. Tirkey b Zonguldak Karaelmas University, Engineering Faculty, Department of Metallurgical Engineering, Zonguldak, Turkey The University of Birmingham, IRC in Materials Processing and School of Metallurgy and Materials, Edgbaston, Birmingham B15 2TT, UK d Imperial College London, Department of Materials, Prince Consort Road, London SW7 2BP e University of Alabama at Birmingham, Department of Materials, Birmingham, AL 35294, USA Received I August 2008: received in revised form 23 September 2008; accepted 27 September 2008 Available online 31 December 2008 Abstract A low cost and reliable ceramic matrix composite fabrication route has been developed. It involves the coating of 2D woven ceramic fibres (Nextel M 720)with oxide nano-size ceramic particles by electrophoretic deposition(EPD) followed by impregnation of the coated fibres with ceramic matrix and warm pressing at 180C to produce the"green"component ready for pressureless sintering. The effects of two different weak interface materials, NdPOa and ZrOz, on the thermomechanical properties of the composites are also examined. Damage mechanisms, such a bonding, fibre fracture, delamination and matrix cracking within the composite plates subjected to tensile loading are analysed using acoustic emission technique and correlated with microstructure. It is shown that the composites with NdPO4 interface, 10%o porosity and 40 vol %o fibre loading have superior thermomechanical properties in terms of strength and damage-tolerant behaviour in multilayer plate form. The improved strength damage-tolerant composites. The final components produced are considered to be suitable for use as shroud seals and insulating plates for ombustor chambers in aircraft engines. C 2008 Elsevier Ltd. All rights reserved. Keywords: Ceramic composite; AL2O3; Nextel M 720: Interphase: Electrophoretic deposition 1. Introduction performance:(a) reinforcement fibres with high strength and modulus, (b)a high temperature-resistant ceramic matrix and Ceramic matrix composites( CMCs)can display quasi- (c) an interface that prevents occurrence of any chemical reac ductile deformation behaviour when mechanisms such as crack tion between fibre and matrix. 4,5 The ceramic matrix selected deflection, fibre pull-out, crack bridging and debonding can be should be chemically compatible with the ceramic fibres and made to operate by optimising the strength of the interface the interface should also be compatible with both to improve between fibre and matrix. -Oxide/oxide CMCs are excellent the overall performance. In recent years, oxide-based compos candidate components for high temperature applications due to ites have been the centre of many research activities as CMCs their increased toughness, inherent oxidation resistance, good are required to be compatible with their service atmospheres thermal shock resistance, decreased flaw sensitivity and damage- which are generally oxidising, such as combustion gases. 3.6-11 tolerant behaviour. -When CMCs are designed for high-risk After selecting the ideal matrix, interface and fibres, the most and high-temperature applications, three constituents should important task is to choose a viable and cost-effective process- carefully be selected and controlled for obtaining the required ing technique for the manufacture of the final component. In the present work we have investigated the use of a novel multi step technology that involves electrophoretic deposition(EPD) Corresponding author. Tel: +90 2124491866: fax: +902124491554 coating of woven ceramic fibres followed by impregnation of E-mail address: cngzky ( yahoo co uk(C Kaya) he ceramic matrix onto individual fibre mats and finally warm 0955-2219 front matter@ 2008 Elsevier Ltd. All rights reserved. doi: 10. 1016/j-jeurceramsoc. 2008.09.027Available online at www.sciencedirect.com Journal of the European Ceramic Society 29 (2009) 1631–1639 Development and characterisation of high-density oxide fibre-reinforced oxide ceramic matrix composites with improved mechanical properties C. Kaya a,∗, F. Kaya b, E.G. Butler c, A.R. Boccaccini d, K.K. Chawla e a Yildiz Technical University, Faculty of Chemistry and Metallurgy, Department of Metallurgical and Materials Engineering, Davutpasa Campus, Esenler, Istanbul, Turkey b Zonguldak Karaelmas University, Engineering Faculty, Department of Metallurgical Engineering, Zonguldak, Turkey c The University of Birmingham, IRC in Materials Processing and School of Metallurgy and Materials, Edgbaston, Bırmingham B15 2TT, UK d Imperial College London, Department of Materials, Prince Consort Road, London SW7 2BP, UK e University of Alabama at Birmingham, Department of Materials, Birmingham, AL 35294, USA Received 1 August 2008; received in revised form 23 September 2008; accepted 27 September 2008 Available online 31 December 2008 Abstract A low cost and reliable ceramic matrix composite fabrication route has been developed. It involves the coating of 2D woven ceramic fibres (NextelTM 720) with oxide nano-size ceramic particles by electrophoretic deposition (EPD) followed by impregnation of the coated fibres with ceramic matrix and warm pressing at 180 ◦C to produce the “green” component ready for pressureless sintering. The effects of two different weak interface materials, NdPO4 and ZrO2, on the thermomechanical properties of the composites are also examined. Damage mechanisms, such as debonding, fibre fracture, delamination and matrix cracking within the composite plates subjected to tensile loading are analysed using acoustic emission technique and correlated with microstructure. It is shown that the composites with NdPO4 interface, 10% porosity and 40 vol.% fibre loading have superior themomechanical properties in terms of strength and damage-tolerant behaviour in multilayer plate form. The improved sinterability and microstructure stability at moderate temperatures ensure both the fibre integrity and load transfer efficiency resulting in high strength damage-tolerant composites. The final components produced are considered to be suitable for use as shroud seals and insulating plates for combustor chambers in aircraft engines. © 2008 Elsevier Ltd. All rights reserved. Keywords: Ceramic composite; AL2O3; NextelTM 720; Interphase; Electrophoretic deposition 1. Introduction Ceramic matrix composites (CMCs) can display quasi￾ductile deformation behaviour when mechanisms such as crack deflection, fibre pull-out, crack bridging and debonding can be made to operate by optimising the strength of the interface between fibre and matrix.1–3 Oxide/oxide CMCs are excellent candidate components for high temperature applications due to their increased toughness, inherent oxidation resistance, good thermal shock resistance, decreased flaw sensitivity and damage￾tolerant behaviour.1–3 When CMCs are designed for high-risk and high-temperature applications, three constituents should carefully be selected and controlled for obtaining the required ∗ Corresponding author. Tel.: +90 2124491866; fax: +90 2124491554. E-mail address: cngzky@yahoo.co.uk (C. Kaya). performance: (a) reinforcement fibres with high strength and modulus, (b) a high temperature-resistant ceramic matrix and (c) an interface that prevents occurrence of any chemical reac￾tion between fibre and matrix.4,5 The ceramic matrix selected should be chemically compatible with the ceramic fibres and the interface should also be compatible with both to improve the overall performance. In recent years, oxide-based compos￾ites have been the centre of many research activities as CMCs are required to be compatible with their service atmospheres which are generally oxidising, such as combustion gases.3,6–11 After selecting the ideal matrix, interface and fibres, the most important task is to choose a viable and cost-effective process￾ing technique for the manufacture of the final component. In the present work we have investigated the use of a novel multi￾step technology that involves electrophoretic deposition (EPD) coating of woven ceramic fibres followed by impregnation of the ceramic matrix onto individual fibre mats and finally warm 0955-2219/$ – see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.jeurceramsoc.2008.09.027