Joumal of the American Ceramic Sociery-Kovar et al. Vol. 80. No. 10 sW. S Coblenz, ""Fibrous Monolithic Ceramics and Method for Production, " 2E. P. Popov, Introduction to Mechanics of Soi U.S.Pat.No.4772524,1988 G. E. HiImas, G A Brady, and J W. Halloran, ""SiC and Si, N, Fibrou PB H. King, "Influence of Architecture on the Mechanical Properties of Fibrous Monolithic Ceramics", Ph.D. Thesis. University of Michigan, Ann 609-14 in Ceramic Transactions, Vol. 51, Fifth internatio on Ceramic Processing Science and Technology. Edited by H Fiber Pullout and Strain Localization in Ceramic- Matrix Hausner, G L Messing, and S.-1. Hirano. American Ceramic Society, Wester- Composites, Mech. Phys. Solids, 41(1|35-53(1993) ville. OH. 1994 A. Brady, "Silicon Nitride/Boron Nitride Fibrous Monolithic Ceram- S. Baskaran, S. D. Nunn, D. Pone 4, pp. 297 forming Textured Ceram- SG. A. Brady, G E. Hilmas, and J. w. Hallor le Coextrusion, se J W. Halloran, ""Fibrous Mon Holmes, and D E. Hasson "Commercial b evelopment of fibrous monolithic nic Ceramics: I. Fabrication. Microstructure. and Indentation Behavior. ' Ceramics, Ceram. Eng. Sci. Proc., 16 [5 673-80(1995) Am. Ceram.Soc,769220916(1993) 33M -Y. He and J. w. Hutchinson, ""Crack Deflection Fibrous Monolithic Ceramics: ll Flexural Strength and Fracture Behavior of the Silicon Carbide/Graphite System, "J.Am. ssv. Gupta, f. Man, and D, Martinez, "calculation, Measurement, Baskaran and J. W. Halloran, ""Fibrous Monolithic Ceramics: IIL, Me- chanical Properties and Oxidation Behavior of the Silicon Carbide/Boron Ni- D. Kovar, M. D. Thouless, and J w. Halloran, "" Crack Deflectio Propagation in Layered Silicon Nitride/Boron Nitride Ceramics,''J.A Hilmas, A. Brady, U. Abdali, G. Zywicki, and J. W. Halloran, ""Fibrous Monoliths: Nonbrittle Fracture from Powder -Processed Ceramics. Mater. Sci 36A. A. Mammoli, A. L. Graham, I.E Reimanis, and D.L. Tullock, "The Eng.A.A915,263-68(1995 Effect of Flaws on the Propagation of Cracks at Bi-materials Interfaces, Acta R Moon, D Kovar, and K. Bowman, ""Preferred Orientation in Si,N/BN Metall. Mater, 43 31 Crack Deflection at Structured Interlay ID Kovar, G A Brady, M. D. Thouless, and J W. Halloran, ""Interfacial ers, "Ceram. Eng. Sci. Proc., 16[]847-54(1995) A J. Phillipps, W.J. Clegg, and T w. Clyne, ""Fracture Behaviour of alL. Mater. 41 PC. A. Folsom, F. w. Zok, and F. F. Lange, ""Flexural Properties of Brittle Mecholsky, A. E. Carlsson, and E.R. Fuller Jr. Materials Research Society, Multilayer Materials: 1, Modeling, J. Am. Ceram. Soc., 77[3]689-96(1994) 40B. Cotterell and J.R. Ri Slightly Curved or Kinked Cracks, Int J. R. W. Trice and J W. Halloran, " Microstructure of Si,N/BN Ceramic Frac,l62]155-69(198 4M.-Y. He, A Bartlett, A G. Evans, and J W. Hutchinson,""Ki rack out of an Interface: Role of In-Plane Stress, "J. Am. Ceram. Soc., 74 14 Cokes and Carbons;p 31 in Proceedings of the Ist and 2nd Conference 767-71(1991) 42K. J. Kang, ""Criteria for Kinking out of Interface Crack, Eng. Fract 1G.S. Rellick and P. M. Adams, "TEM Studies of Resin-Based Matrix Mech, 49 [41 Microstructure in Carbon/Carbon Composites, Carbon, 32 [1 127-44(1994) A J Phillipps, w.J. Clegg, and T. w. CI The Failure of Laye ISW. Sinclair and H. Simmons, ""Micro ure and Thermal Shock Behav 16B.T.Kelly, s"The An Mater: Set, Lent, 6, 627-29(1987). 4D. Kovar and M. D. Thouless, ""Simple Method for Measuring Frictional Sliding Resistance and Ener .. Am. ce Interpretation by the Semicontinuum Model, Philos. Mag, 32 [4]859-67 ram Soc., 80 [3]673-79(1997) 4R. L. Tsai and R. Raj, Creep Fracture in Ceramics Containing Small Yates, M.J. Ovary, and O. Pirgon,"The Anisotropic Thermal Expan- sion of Boron Nitride I. Experimental Results and Their Analysis, ""Philos. 46M. D. Thouless, "A Review of Creep Rupture in Materials Containing an ag,32|4]847-57(1975 A Curtin, "Theory of Mechanical Properties of Ceramic-Matrix Com- 77M. K. Ferber and M. G. Jenkins, ""Evaluation of the Strength and Creep- posites, J Am Ceram Soc., 74 [11] 2837-45(1991) Fibre-Reinforced Brittle-Matrix Composites, "J Mater. Sci., 29, 3857-96 derhorn, B J Hockey, R E. Krause, and GG Tensile Creep in Silicon Ni- Standard Practice for Measuring Ultrasonic Velocity in Material m. Ceram.Soc,7818]2085-96(1995 ASTM tion E 494-92a, pp. 179-90. 1994 Annual Book of ASTM Stan- 49M. N. Menon, H. T Fange, D. C. Wu, M. G. Jenkins, M. K. Ferber, K.L. Testing and of an Advanced Silicon Nitride: Part 1, Experimental Observations, J.Am P G. Charalambides, J. Lund, A G. Evans, and R. M. McMeeking,"A Test Specimen for the Fracture Resistance of Bimaterial Inter- sow.A Sanders and L. E. Groseclose, "Flexural Stress Rupture and Creep of faces, ' J. Appl. Mech., 56 [3] 77-82(1989) 221 M. Daniel and O. Ishai. Er ring Mechanics of Composite Materials, pp. 48-73. Oxford University Press, Oxford, U. K., 1994 Iu and s H. Hsu, Fractu Multilayer Silicon Nitride G L DePoorter, T. K. Brog, and M. J Readey, ""Structural Ceramics; pp 1019-24 in Properties and Selection, Vol. 2, ASM Metals Handbook. ASM Bo 52C. A. Folsom. F. w. Zok and F.F. "Flexural Properties of Brittle International, Metals Park, OH, 1990. Multilayer Materials: Il, Experiments, Ceram Soc., 77[] 2081-87 24H. O. Pierson, Handbook of Carbon, Graphite, Diamond, and Fullerines Properties, Processing, and Applications: p. 191. Noyes Publications, Park Baskaran and J w. Halloran. "SiC-Based Fibrous monolithic Ceram- s, Ceram. Eng. Sci. Proc., 14 [9-10J813-23(1993) Mechanical Properties, and Thermal P luminum Oxide Fibrous monoliths,. M.S. Thesis. Uni- Edgar INSPEC, London, U. K. pegas of Group ll Nitrides. Edited by J.H. ichigan, Ann Arbor, MI, 1996 U. K. Abdali, "" Metal-Toughened Oxide Fibrous Monoliths", M.S. Thesis cs: IV, Mechanical Properties and Oxidation Behavior of the Alumina/Nickel High Temp. Chem. Inorg. Ceram. Mater. Proc. Conf. 30, 167-80(1977) System, " J. Am. Ceram Soc., 77[5]1256-62(1994).3 W. S. Coblenz, ‘‘Fibrous Monolithic Ceramics and Method for Production,’’ U.S. Pat. No. 4 772 524, 1988. 4 G. E. Hilmas, G. A. Brady, and J. W. Halloran, ‘‘SiC and Si3N4 Fibrous Monoliths: Nonbrittle Fracture from Powder-Processed Ceramics Produced by Coextrusion’’; pp. 609–14 in Ceramic Transactions, Vol. 51, Fifth International Conference on Ceramic Processing Science and Technology. Edited by H. Hausner, G. L. Messing, and S.-I. Hirano. American Ceramic Society, Wester￾ville, OH, 1994. 5 G. A. Brady, G. E. Hilmas, and J. W. Halloran, ‘‘Forming Textured Ceram￾ics by Multiple Coextrusion’’; see Ref. 4, pp. 297–301. 6 S. Baskaran, S. D. Nunn, D. Popovic, and J. W. Halloran, ‘‘Fibrous Mono￾lithic Ceramics: I, Fabrication, Microstructure, and Indentation Behavior,’’ J. Am. Ceram. Soc., 76 [9] 2209–16 (1993). 7 S. Baskaran and J. W. Halloran, ‘‘Fibrous Monolithic Ceramics: II, Flexural Strength and Fracture Behavior of the Silicon Carbide/Graphite System,’’ J. Am. Ceram. Soc., 76 [9] 2217–24 (1993). 8 S. Baskaran and J. W. Halloran, ‘‘Fibrous Monolithic Ceramics: III, Me￾chanical Properties and Oxidation Behavior of the Silicon Carbide/Boron Ni￾tride System,’’ J. Am. Ceram. Soc., 77 [5] 1249–55 (1994). 9 G. Hilmas, A. Brady, U. Abdali, G. Zywicki, and J. W. Halloran, ‘‘Fibrous Monoliths: Nonbrittle Fracture from Powder-Processed Ceramics,’’ Mater. Sci. Eng. A, A915, 263–68 (1995). 10R. Moon, D. Kovar, and K. Bowman, ‘‘Preferred Orientation in Si3N4/BN Fibrous Monoliths,’’ unpublished work. 11D. Kovar, G. A. Brady, M. D. Thouless, and J. W. Halloran, ‘‘Interfacial Fracture between Boron Nitride and Silicon Nitride and Its Applications to the Failure Behavior of Fibrous Monolithic Ceramics’’; pp. 243–48 in Instability Dynamics, Scaling, and Ductile/Brittle Behavior, Materials Research Society Symposium Proceedings, Vol. 409. Edited by R. L. Blumberg Selinger, J. J. Mecholsky, A. E. Carlsson, and E. R. Fuller Jr. Materials Research Society, Pittsburgh, PA, and Boston, MA, 1996. 12R. W. Trice and J. W. Halloran, ‘‘Microstructure of Si3N4/BN Ceramic Composite,’’ unpublished work. 13S. Mrozwski, ‘‘Mechanical Strength, Thermal Expansion, and Structure of Cokes and Carbons’’; p. 31 in Proceedings of the 1st and 2nd Conference on Carbon. Waverly Press, Baltimore, MD, 1956. 14G. S. Rellick and P. M. Adams, ‘‘TEM Studies of Resin-Based Matrix Microstructure in Carbon/Carbon Composites,’’ Carbon, 32 [1] 127–44 (1994). 15W. Sinclair and H. Simmons, ‘‘Microstructure and Thermal Shock Behav￾ior of BN Composites,’’ J. Mater. Sci. Lett., 6, 627–29 (1987). 16B. T. Kelly, ‘‘The Anisotropic Thermal Expansion of Boron Nitride II. Interpretation by the Semicontinuum Model,’’ Philos. Mag., 32 [4] 859–67 (1975). 17B. Yates, M. J. Ovary, and O. Pirgon, ‘‘The Anisotropic Thermal Expan￾sion of Boron Nitride I. Experimental Results and Their Analysis,’’ Philos. Mag., 32 [4] 847–57 (1975). 18W. A. Curtin, ‘‘Theory of Mechanical Properties of Ceramic-Matrix Com￾posites,’’ J. Am. Ceram. Soc., 74 [11] 2837–45 (1991). 19A. G. Evans and F. W. Zok, ‘‘Review—The Physics and Mechanics of Fibre-Reinforced Brittle-Matrix Composites,’’ J. Mater. Sci., 29, 3857–96 (1994). 20‘‘Standard Practice for Measuring Ultrasonic Velocity in Materials,’’ ASTM Designation E 494-92a; pp. 179–90. 1994 Annual Book of ASTM Stan￾dards, Vol. 03.03. Edited by P. C. Fazio, et al. American Society for Testing and Materials, Philadelphia, PA, 1994. 21P. G. Charalambides, J. Lund, A. G. Evans, and R. M. McMeeking, ‘‘A Test Specimen for Determining the Fracture Resistance of Bimaterial Inter￾faces,’’ J. Appl. Mech., 56 [3] 77–82 (1989). 22I. M. Daniel and O. Ishai, Engineering Mechanics of Composite Materials; pp. 48–73. Oxford University Press, Oxford, U.K., 1994. 23G. L. DePoorter, T. K. Brog, and M. J. Readey, ‘‘Structural Ceramics’’; pp. 1019–24 in Properties and Selection, Vol. 2, ASM Metals Handbook. ASM International, Metals Park, OH, 1990. 24H. O. Pierson, Handbook of Carbon, Graphite, Diamond, and Fullerines: Properties, Processing, and Applications; p. 191. Noyes Publications, Park Ridge, NJ, 1993. 25J. H. Edgar, ‘‘Crystal Structure, Mechanical Properties, and Thermal Prop￾erties of BN’’; pp. 7–21 in Properties of Group III Nitrides. Edited by J. H. Edgar. INSPEC, London, U.K., 1994. 26A. W. Moore, ‘‘Characterization of Pyrolytic Boron Nitride for Semicon￾ductor Materials Processing,’’ J. Cryst. Growth, 106 [1] 6–15 (1990). 27N. J. Archer, ‘‘The Preparation and Properties of Pyrolytic Boron Nitride,’’ High Temp. Chem. Inorg. Ceram. Mater. Proc. Conf., 30, 167–80 (1977). 28E. P. Popov, Introduction to Mechanics of Solids; 188–89. Prentice-Hall, Englewood Cliffs, NJ, 1968. 29B. H. King, ‘‘Influence of Architecture on the Mechanical Properties of Fibrous Monolithic Ceramics’’; Ph.D. Thesis. University of Michigan, Ann Arbor, MI, 1997. 30W. A. Curtin, ‘‘Fiber Pullout and Strain Localization in Ceramic-Matrix Composites,’’ J. Mech. Phys. Solids, 41 [1] 35–53 (1993). 31G. A. Brady, ‘‘Silicon Nitride/Boron Nitride Fibrous Monolithic Ceram￾ics’’; M.S. Thesis. University of Michigan, Ann Arbor, MI, 1996. 32G. A. Danko, D. Popovic, K. Stuffle, B. H. King, J. W. Halloran, J. W. Holmes, and D. F. Hasson, ‘‘Commercial Development of Fibrous Monolithic Ceramics,’’ Ceram. Eng. Sci. Proc., 16 [5] 673–80 (1995). 33M.-Y. He and J. W. Hutchinson, ‘‘Crack Deflection at an Interface between Dissimilar Elastic Materials,’’ Int. J. Solids Struct., 25 [9] 1053–67 (1989). 34V. Gupta, J. Yuan, and D. Martinez, ‘‘Calculation, Measurement, and Con￾trol of Interface Strength in Composites,’’ J. Am. Ceram. Soc., 76 [2] 305–15 (1993). 35D. Kovar, M. D. Thouless, and J. W. Halloran, ‘‘Crack Deflection and Propagation in Layered Silicon Nitride/Boron Nitride Ceramics,’’ J. Am. Ce￾ram. Soc., in press. 36A. A. Mammoli, A. L. Graham, I. E. Reimanis, and D. L. Tullock, ‘‘The Effect of Flaws on the Propagation of Cracks at Bi-materials Interfaces,’’ Acta Metall. Mater., 43 [3] 1149–56 (1995). 37C. M. Warwick and W. J. Clegg, ‘‘Crack Deflection at Structured Interlay￾ers,’’ Ceram. Eng. Sci. Proc., 16 [5] 847–54 (1995). 38A. J. Phillipps, W. J. Clegg, and T. W. Clyne, ‘‘Fracture Behaviour of Ceramic Laminates in Bending—I. Modeling of Crack Propagation,’’ Acta Met￾all. Mater., 41 [3] 805–17 (1993). 39C. A. Folsom, F. W. Zok, and F. F. Lange, ‘‘Flexural Properties of Brittle Multilayer Materials: I, Modeling,’’ J. Am. Ceram. Soc., 77 [3] 689–96 (1994). 40B. Cotterell and J. R. Rice, ‘‘Slightly Curved or Kinked Cracks,’’ Int. J. Fract., 16 [2] 155–69 (1980). 41M.-Y. He, A. Bartlett, A. G. Evans, and J. W. Hutchinson, ‘‘Kinking of a Crack out of an Interface: Role of In-Plane Stress,’’ J. Am. Ceram. Soc., 74 [4] 767–71 (1991). 42K. J. Kang, ‘‘Criteria for Kinking out of Interface Crack,’’ Eng. Fract. Mech., 49 [4] 587–98 (1994). 43A. J. Phillipps, W. J. Clegg, and T. W. Clyne, ‘‘The Failure of Layered Ceramics in Bending and Tension,’’ Composites, 25 [7] 524–33 (1994). 44D. Kovar and M. D. Thouless, ‘‘Simple Method for Measuring Frictional Sliding Resistance and Energy Dissipation in Layered Ceramics,’’ J. Am. Ce￾ram. Soc., 80 [3] 673–79 (1997). 45R. L. Tsai and R. Raj, ‘‘Creep Fracture in Ceramics Containing Small Amounts of a Liquid Phase,’’ Acta Metall., 30, 1043–58 (1982). 46M. D. Thouless, ‘‘A Review of Creep Rupture in Materials Containing an Amorphous Phase,’’ Res. Mech., 22, 213–42 (1987). 47M. K. Ferber and M. G. Jenkins, ‘‘Evaluation of the Strength and Creep￾Fatigue Behavior of Hot Isostatically Pressed Silicon Nitride,’’ J. Am. Ceram. Soc., 78 [8] 2453–62 (1992). 48W. E. Luecke, S. M. Weiderhorn, B. J. Hockey, R. E. Krause, and G. G. Long, ‘‘Cavitation Contributes Substantially to Tensile Creep in Silicon Ni￾tride,’’ J. Am. Ceram. Soc., 78 [8] 2085–96 (1995). 49M. N. Menon, H. T. Fange, D. C. Wu, M. G. Jenkins, M. K. Ferber, K. L. Moare, C. R. Hubbard, and T. A. Nolan, ‘‘Creep and Stress Rupture Behavior of an Advanced Silicon Nitride: Part I, Experimental Observations,’’ J. Am. Ceram. Soc., 77 [5] 1217–27 (1994). 50W. A. Sanders and L. E. Groseclose, ‘‘Flexural Stress Rupture and Creep of Selected Commercial Silicon Nitrides,’’ J. Am. Ceram. Soc., 76 [2] 553–56 (1993). 51H. Liu and S. H. Hsu, ‘‘Fracture Behavior of Multilayer Silicon Nitride/ Boron Nitride Ceramics,’’ J. Am. Ceram. Soc., 79 [9] 2452–57 (1996). 52C. A. Folsom, F. W. Zok, and F. F. Lange, ‘‘Flexural Properties of Brittle Multilayer Materials: II, Experiments,’’ J. Am. Ceram. Soc., 77 [8] 2081–87 (1994). 53S. Baskaran and J. W. Halloran, ‘‘SiC-Based Fibrous Monolithic Ceram￾ics,’’ Ceram. Eng. Sci. Proc., 14 [9–10] 813–23 (1993). 54G. J. Zywicki, ‘‘Aluminum Oxide Fibrous Monoliths’’; M.S. Thesis. Uni￾versity of Michigan, Ann Arbor, MI, 1996. 55U. K. Abdali, ‘‘Metal-Toughened Oxide Fibrous Monoliths’’; M.S. Thesis. University of Michigan, Ann Arbor, MI, 1996. 56S. Baskaran, S. D. Nunn, and J. W. Halloran, ‘‘Fibrous Monolithic Ceram￾ics: IV, Mechanical Properties and Oxidation Behavior of the Alumina/Nickel System,’’ J. Am. Ceram. Soc., 77 [5] 1256–62 (1994). h 2486 Journal of the American Ceramic Society—Kovar et al. Vol. 80, No. 10