88 D B. Marshall, J.B. Davis Current Opinion in Solid State and Materials Science 5(2001)283-20 d performance of an all-oxide ceramic composite. J Am Ceram site (mullite alumina) with systematically varied density and Socl998;81:2077-86 strength of the matrix L*16 Zok Fw, Levi CG. Mechanical es of porous-matrix [27 Morgan PED, Marshall DB. Ceramic composites of monazite and omposites. Adv Eng Mater 2001; 3: 15-23, Review of porous lumina. J Am Ceram Soc 1995: 78: 1553-63 posites, covering mechanics considerations in th [28]Goettler RW, Sambasivan S, Dravid V, Kim S Interfaces in oxide fiber- oxide matrix ceramic composites. In: Pechenik A, Kalia rties under tensile loading in various directions as well as in RH, Vashita P, eds Computer Aided Design of sence of notches and holes, and assessment of prospects for Materials, New York: Oxford University Press, 1999: 333-349 CawO, ErTaO, interphases: strengths of Scheelite-coated [17 Levi ok FW, Yang JY, Mattoni M, Lofvander JPA N6100 fibers after 1100C/1 h-no strength loss. howeve Microstructural design of stable po matrices for strength loss in comp made with Al, O, polymer ceramic composites. Z Metallkde 1999: 90: 1037-47, The princi- [29] Lewis MH, Tye A, Butler EG, Doleman PA. Oxide CMCs les guiding the microstructural design of porous matrix compos thesis and novel fibre development. J Eur Ceram ites using two particulate oxide constituents, in different size Soc 2000, 20: 639-44, Deposition of rare-earth vanadates and scales and with distinctly different sintering kinetic hosphate from colloidal precursors or by magnetron sputterin Thermal stability with reference to al fibres and matrice recursor(Al, (OH)s CI) on microstructure and tensile 30] Marshall DB, Waldrop JR, Morgan PED. Thermal grooving at the described monazite. Acta Mate [18 Harrison MG, Millard ML, Szweda A. Fiber Reinforced Ceramic 2000: 48: 4471-4, Atomic force microscopy of monazite alumina Matrix ce te Member and method for Making. US Patent interface fracture surfaces No.5306554; UK Patent No.2230259(1994 [31 Marshall DB, Davis JB, Morgan PED, Waldrop JR, Porter JP [19]Kramb VA, John R, Zawada LP Notched fracture behavior of an Properties of La-monazite as an interphase in oxide composites. Z oxide/oxide ceramic-matrix composite. J Am Ceram Soc Metallkde 1999: 90: 1048-52, Room temperature deformation of 1999: 82: 3087-96, Tensile test data from Gen IV(N610) at room onazite at rough sliding interfaces. temperature and 950"C: shows some notch sensitivity at RT(66% [32 Hay Rs Monazite and scheelite deformation mechanisms. Ceram net section strength) and large notch sensitivity at 950C(30% net Eng Sci Proc 2000: 21: 203-28, TEM observations showing dislo- ection strength ). Observations of damage from fracture surfaces cations and twins in materials deformed at room temperature nd polished sections indicate embrittlement at 950C [33] Meldrum A, Boatner LA, Ewing RC. A comparison of radiation [20 Buchanan DJ, John R, Zawada LP. Notched fracture behavior of effects in crystalline ABO4 type phosphates and silicates. Mineral xide-oxide Nextel 720/As composite. Ceram Eng Sci Proc Mag 2000: 64: 185-94, Radiation damage was monitored 2000: 21: 567-74, Tensile test data showing no effect of notches function of temperature in situ in a transmission electron micro- on net section strength of Nextel 710/alumino-silicate matrix ope. The critical temperature, above which the recrystallization omposite at temperatures up to 1100.C, and small effect at processes are faster than damage accumulation and amorphization 1200.C (-20% reduction). annot be induced, was only 35C for LaPO4, much lower than [21] John R, Buchanan DJ, Zawada LP. Creep deformation and ruptur for other phosphates and silicates behavior of a notched oxide-oxide Nextel 720/As composite. [34] Parthasarathy TA, Boakeye E, Cinibulk MK, Perry MD. Fabrica- Ceram Eng Sci Proc 2000: 21: 567-74, Tensile creep data from the tion and testing of oxide/oxide microcomposites with monazite same composites as in Ref. 20). and hibonite as interlayers. J Am Ceram Soc 1999: 82: 3575-83 [22] Jurf RA, Butner SC. Advances in oxide-oxide CMC J Eng Gas Strengths of single fiber composites: sapphire+LaPO, +10 ur Turbines Power 2000: 122: 202-5. Tensile strengths lextel Al,O, Also hibonite(CaAln,g) 710/alumino-silicate matrix composite after long-term aging at 35] Keller KA, Mah T-L, Boakye EE, Parthasarathy TA Gel-casting temperatures up to 1200.C nd reaction bonding of oxide-oxide minicomposites with mona [23] Haslam JJ, Berroth KE, Lange FF. Processing and properties of zite interphase. Ceram Eng Sci Proc 2000, 21: 525-34 n all-oxide composite with a porous matrix J Eur Ceram Soc [*36 Keller KA, Mah T, Parthasarathy TA, Boakye EE, Cinibulk M. 2000: 20: 607-18, Formation of mullite-zirconia matrix composite Evaluation of all-oxide composites based on coated Nextel 610 using a vibro- impregnation process with tape freezing followed and 650 fibers. Ceramic Engineering and Science Proceedings by sintering without shrinkage in a reactive atmosphere 2001, in press. Unidirectional composites of Nextel fibers(610, [24] Carelli E, Fujita H, Yang J, Zok Fw. On the mechanical properties 650 and 720) with monazite coatings and alumina matrix: after of a porous-matrix ceramic composite following thermal aging, J heat treatments at 1100 and 1200C, the strengths of composites Am. Ceram. Soc. (in press). Effect of long-term aging at with monazite coatings were all higher than those of the core. temperatures up to 1200"C on properties of Nextel 720/mullite sponding control specimens, the largest differences being seen lumina matrix composite after 1200.C treatment (e.g, 200 MPa for coated Nextel 610 [25 Heathcote JA, Gong XY, Yang JY, Ramamurty U, Zok Fw omposite after 5 h at 1200C, 45 MPa for uncoated control J Am Ceram Soc 1999: 82. 2721-30. Detailed measurements of [37] Davis JB, Marshall DB, Morgan PED. Monazite containing room temperature tensile properties of 2-D composite consisting oxide-oxide composites. J Eur Ceram Soc 2000: 20:583-7, Prop- of Nextel 610 fibers in porous mullite- alumina matrix(both 0/90 erties of composite formed by infiltrating Nextel" 610 fibe nd 45). Notch sensitivity is assessed using center-hole tension preform with slurry of alumina in solution precursor for monazite tests: some loss of strength is observed in the presence of notches. *38] Davis JB, Marshall DB, Morgan PED. Oxide composites o but much less than for a fully notch sensitive material. Effects o AlO and LaPO. J Eur Ceram Soc 1999 19: 2421-6. Fracture ole size on strength were rationalized by comparing with stres servations from composite formed by infiltrating NextelTM 610 tributions predicted using non-linear continuum and shear band fiber preform with slurry of alumina in solution precursor for monazite and from composite with sapphire fibers and fully dense [26] Mattoni M, Yang JY, Levi CG, Zok Fw. Effects of a precursor. monazite matrIx derived alumina on the mechanical properties of a porous matrix, [39] Morgan PED, Marshall DB, Davis JB, Housley RM. The weak all-oxide ceramic composite, Mater. Sci. Eng.(2000)in press interface between monazites and refractory ceramic oxides. In Measurements of changes in properties of porous matrix compo- Pechenik A, Kalia RK Vashishta P, eds Computer Aided Design288 D.B. Marshall, J.B. Davis / Current Opinion in Solid State and Materials Science 5 (2001) 283–289 and performance of an all-oxide ceramic composite. J Am Ceram site (mullite alumina) with systematically varied density and Soc 1998;81:2077–86. strength of the matrix. [**16] Zok FW, Levi CG. Mechanical properties of porous-matrix [27] Morgan PED, Marshall DB. Ceramic composites of monazite and composites. Adv Eng Mater 2001;3:15–23, Review of porous alumina. J Am Ceram Soc 1995;78:1553–63. matrix composites, covering mechanics considerations in the [28] Goettler RW, Sambasivan S, Dravid V, Kim S. Interfaces in oxide design of the composite microstructures, a survey of mechanical fiber — oxide matrix ceramic composites. In: Pechenik A, Kalia properties under tensile loading in various directions as well as in RH, Vashita P, eds. Computer Aided Design of High-Temperature the presence of notches and holes, and assessment of prospects for Materials, New York: Oxford University Press, 1999: 333–349. long-term stability. CaWO & ErTaO interphases: strengths of Scheelite-coated 4 4 [*17] Levi CG, Zok FW, Yang JY, Mattoni M, Lofvander JPA. N6100 fibers after 11008C/1 h — no strength loss. However Microstructural design of stable porous matrices for all-oxide strength loss in composites made with Al O polymer 2 3 ceramic composites. Z Metallkde 1999;90:1037–47, The princi- [29] Lewis MH, Tye A, Butler EG, Doleman PA. Oxide CMCs: ples guiding the microstructural design of porous matrix compos- interphase synthesis and novel fibre development. J Eur Ceram ites using two particulate oxide constituents, in different size Soc 2000;20:639–44, Deposition of rare-earth vanadates and scales and with distinctly different sintering kinetics are are phosphates from colloidal precursors or by magnetron sputtering. reviewed. The effects of multiple reinfiltration with an alumina Thermal stability with reference to potential fibres and matrices. precursor (Al (OH) Cl) on microstructure and tensile properties 2 5 [30] Marshall DB, Waldrop JR, Morgan PED. Thermal grooving at the are described. interface between alumina and monazite. Acta Mater [18] Harrison MG, Millard ML, Szweda A. Fiber Reinforced Ceramic 2000;48:4471–4, Atomic force microscopy of monazite alumina Matrix Composite Member and method for Making. US Patent interface fracture surfaces. No. 5 306 554; UK Patent No. 2 230 259 (1994). [*31] Marshall DB, Davis JB, Morgan PED, Waldrop JR, Porter JP. [19] Kramb VA, John R, Zawada LP. Notched fracture behavior of an Properties of La-monazite as an interphase in oxide composites. Z oxide/oxide ceramic-matrix composite. J Am Ceram Soc Metallkde 1999;90:1048–52, Room temperature deformation of 1999;82:3087–96, Tensile test data from Gen IV (N610) at room monazite at rough sliding interfaces. temperature and 9508C: shows some notch sensitivity at RT (66% [*32] Hay RS. Monazite and scheelite deformation mechanisms. Ceram net section strength) and large notch sensitivity at 9508C (30% net Eng Sci Proc 2000;21:203–28, TEM observations showing dislo￾section strength). Observations of damage from fracture surfaces cations and twins in materials deformed at room temperature. and polished sections indicate embrittlement at 9508C. [33] Meldrum A, Boatner LA, Ewing RC. A comparison of radiation [20] Buchanan DJ, John R, Zawada LP. Notched fracture behavior of effects in crystalline ABO -type phosphates and silicates. Mineral 4 oxide-oxide Nextel 720/AS composite. Ceram Eng Sci Proc Mag 2000;64:185–94, Radiation damage was monitored as a 2000;21:567–74, Tensile test data showing no effect of notches function of temperature in situ in a transmission electron micro￾on net section strength of Nextel 710/alumino-silicate matrix scope. The critical temperature, above which the recrystallization composite at temperatures up to 11008C, and small effect at processes are faster than damage accumulation and amorphization 12008C (|20% reduction). cannot be induced, was only 358C for LaPO , much lower than 4 [21] John R, Buchanan DJ, Zawada LP. Creep deformation and rupture for other phosphates and silicates. behavior of a notched oxide-oxide Nextel 720/AS composite. [34] Parthasarathy TA, Boakeye E, Cinibulk MK, Perry MD. Fabrica￾Ceram Eng Sci Proc 2000;21:567–74, Tensile creep data from the tion and testing of oxide/oxide microcomposites with monazite same composites as in Ref. [20]. and hibonite as interlayers. J Am Ceram Soc 1999;82:3575–83, [22] Jurf RA, Butner SC. Advances in oxide-oxide CMC. J Eng Gas Strengths of single fiber composites: sapphire1LaPO4110 mm Turbines Power 2000;122:202–5, Tensile strengths of Nextel Al O Also hibonite (CaAl O ). 2 3 12 19 710/alumino-silicate matrix composite after long-term aging at [35] Keller KA, Mah T-I, Boakye EE, Parthasarathy TA. Gel-casting temperatures up to 12008C. and reaction bonding of oxide-oxide minicomposites with mona- [23] Haslam JJ, Berroth KE, Lange FF. Processing and properties of zite interphase. Ceram Eng Sci Proc 2000;21:525–34. an all-oxide composite with a porous matrix. J Eur Ceram Soc [**36] Keller KA, Mah T, Parthasarathy TA, Boakye EE, Cinibulk M. 2000;20:607–18, Formation of mullite-zirconia matrix composite Evaluation of all-oxide composites based on coated Nextel 610 using a vibro-impregnation process with tape freezing followed and 650 fibers. Ceramic Engineering and Science Proceedings by sintering without shrinkage in a reactive atmosphere. 2001, in press. Unidirectional composites of NextelE fibers (610, [*24] Carelli E, Fujita H, Yang J, Zok FW. On the mechanical properties 650 and 720) with monazite coatings and alumina matrix: after of a porous-matrix ceramic composite following thermal aging, J. heat treatments at 1100 and 12008C, the strengths of composites Am. Ceram. Soc. (in press). Effect of long-term aging at with monazite coatings were all higher than those of the corre￾temperatures up to 12008C on properties of Nextel 720/mullite- sponding control specimens, the largest differences being seen alumina matrix composite. after 12008C treatment (e.g., 200 MPa for coated Nextel 610 [*25] Heathcote JA, Gong XY, Yang JY, Ramamurty U, Zok FW. composite after 5 h at 12008C, 45 MPa for uncoated control In-plane mechanical properties of an all-oxide ceramic composite. composite). J Am Ceram Soc 1999;82:2721–30, Detailed measurements of [*37] Davis JB, Marshall DB, Morgan PED. Monazite containing room temperature tensile properties of 2-D composite consisting oxide-oxide composites. J Eur Ceram Soc 2000;20:583–7, Prop￾of Nextel 610 fibers in porous mullite-alumina matrix (both 0/90 erties of composite formed by infiltrating NextelE 610 fiber and 458). Notch sensitivity is assessed using center-hole tension preform with slurry of alumina in solution precursor for monazite. tests: some loss of strength is observed in the presence of notches, [*38] Davis JB, Marshall DB, Morgan PED. Oxide composites of but much less than for a fully notch sensitive material. Effects of Al O and LaPO . J Eur Ceram Soc 1999;19:2421–6, Fracture 23 4 hole size on strength were rationalized by comparing with stress observations from composite formed by infiltrating NextelTM 610 distributions predicted using non-linear continuum and shear band fiber preform with slurry of alumina in solution precursor for models. monazite and from composite with sapphire fibers and fully dense [*26] Mattoni M, Yang JY, Levi CG, Zok FW. Effects of a precursor- monazite matrix. derived alumina on the mechanical properties of a porous-matrix, [39] Morgan PED, Marshall DB, Davis JB, Housley RM. The weak all-oxide ceramic composite, Mater. Sci. Eng. (2000) in press. interface between monazites and refractory ceramic oxides. In: Measurements of changes in properties of porous matrix compo- Pechenik A, Kalia RK Vashishta P, eds. Computer Aided Design