./. Appl. Ceram. Technol, 7/3/291-303(2010) DOk:10.111117447402.2010.02485x International Journal o pplied Ceramic TECHNOLOGY ceramic Product D Influence of interface Characteristics on the mechanical Properties of Hi-Nicalon type-S or Tyranno-SA3 Fiber-Reinforced SiC/SiC Minicomposites C. Sauder CEA SACLAY, DEN/DMN/SRMA/LTMEX, 91191 Gif sur Yvette, france A. Brusson and J. Lamon Laboratoire des Composites Thermostructuraux, University of Bordeaux/CNRS, 3, allee de la boetie 33600 Pessac, france The tensile behavior of CVI SiC/SiC composites with Hi-Nicalon type-S(Hi-Nicalon S)or Tyranno-SA3(SA3)fibers as investigated using minicomposite test specimens. Minicomposites contain a single tow. The mechanical behavior was correlated with microstructural features including tow failure strength and interface characteristics. The Hi-NicalonS fiber- reinforced minicomposites exhibited a conventional damage-tolerant response, comparable to that observed on composites reinforced by untreated Nicalon or Hi-Nicalon fibers and possessing weak fiber/matrix interfaces. The SA3 fiber-reinforced nicomposites exhibited larger interfacial shear stresses and erratic behavior depending on the fiber Py C coating thickness. Differences in the mechanical behavior were related to differences in the fiber surface roughness. Introduction ties at high temperatures, in a hostile environment. The SiC/SiC composites prepared using the chemical vapor Next generations of nuclear reactors require st infiltration(CVI)method, and reinforced with the latest ural materials that retain excellent mechanical proper- near-stoichiometric SiC fibers(such as Hi-Nicalon type- S and Tyranno-SA3 fibers, hereafter Hi-NicalonS and SA3), appear as promising candidates for nuclear appli an Ceramic Society cations such as fuel cladding in gas fast reactors.Influence of Interface Characteristics on the Mechanical Properties of Hi-Nicalon type-S or Tyranno-SA3 Fiber-Reinforced SiC/SiC Minicomposites C. Sauder CEA SACLAY, DEN/DMN/SRMA/LTMEX, 91191 Gif sur Yvette, France A. Brusson and J. Lamon* Laboratoire des Composites Thermostructuraux, University of Bordeaux/CNRS, 3, alle´e de la Boe´tie, 33600 Pessac, France The tensile behavior of CVI SiC/SiC composites with Hi-Nicalon type-S (Hi-NicalonS) or Tyranno-SA3 (SA3) fibers was investigated using minicomposite test specimens. Minicomposites contain a single tow. The mechanical behavior was correlated with microstructural features including tow failure strength and interface characteristics. The Hi-NicalonS fiber￾reinforced minicomposites exhibited a conventional damage-tolerant response, comparable to that observed on composites reinforced by untreated Nicalon or Hi-Nicalon fibers and possessing weak fiber/matrix interfaces. The SA3 fiber-reinforced minicomposites exhibited larger interfacial shear stresses and erratic behavior depending on the fiber PyC coating thickness. Differences in the mechanical behavior were related to differences in the fiber surface roughness. Introduction Next generations of nuclear reactors require struc￾tural materials that retain excellent mechanical proper￾ties at high temperatures, in a hostile environment. The SiC/SiC composites prepared using the chemical vapor infiltration (CVI) method, and reinforced with the latest near-stoichiometric SiC fibers (such as Hi-Nicalon type￾S and Tyranno-SA3 fibers, hereafter Hi-NicalonS and SA3), appear as promising candidates for nuclear appli￾cations such as fuel cladding in gas fast reactors.1–3 Int. J. Appl. Ceram. Technol., 7 [3] 291–303 (2010) DOI:10.1111/j.1744-7402.2010.02485.x Ceramic Product Development and Commercialization *lamon@lcts.u-bordeaux1.fr r 2010 The American Ceramic Society