tes Science and Technology 61(2001)1561-1570 fracture specimen correlated well with both the length of [5] Zawada LP, Lee SS. Evaluation of four CMCs for aerospace the continuous surface matrix crack and the extent of the turbine engine divergent flaps and seals. Ceram Eng Sci Proc matrix cracking away from the crack plane. At both 23 (6] Heredia FE, Spearing SM, Mackin TJ, He MY. Evans AG 95:16(4):337-9 and 950 C, the extent of matrix cracking extended Notch effects in carbon matrix composites. J Am Ceram Soc beyond the 0o fiber failure locations. Thus, good correla 994:77(11):2817-27 ion between the ultrasonic C-scans and extent of matrix [7 Mackin TJ, Purcell TE, He MY, Evans AG. Notch sensitivit cracking indicated C-scans can be used effectively to and stress redistribution in three ceramic-matrix composites 1995; monitor damage progression from notches in oxide/ 3(7):1719-28 oxide cmc [8 Kramb VA, John R, Zawada LP. Notched fracture an oxide/oxide ceramic matrix composite. J Am Cer [9 Kramb VA Notched fracture behavior of an oxide/oxide cerar Acknowledgements matrix composite. PhD thesis, University of Dayton, Department This research was conducted at the Materials and [0 Stubbs DA, Clemons GS. Screening metal matrix composites sing ultrasonic reflector plate and X-ray radiography non- Manufacturing Directorate, Air Force Research Labora- destructive evaluation techniques. In: Characterization of tita- tory(AFrl/MlLN, wright-Patterson Air Force Base, nium matrix composites, voL. VIl--mechanical behavior and OH 45433-7817. The NDE facilities were provided by the rance of TMCs. NASP Technical Memorandum NDE Branch of AFRL (AFRL/MLLP). vAK.was in part by the Dayton Area Graduate St [1] Stubbs DA, Clemons GS. Guidelines for standardizing the gain udIes Institute(DAGSi) and in part by AFOSR/ AASERT of ultrasonic inspection systems used to acquire ultrasonic reflec tor plate C-scans. In: Characterization of titanium matrix com- Program( Contract No. F49620-95-1-0500) d damage tolerance of TMCs, vo VIL. NASP Technical Memorandum 1199. 1995. [2] 3M Company Product Data Sheet, 3M Ceramic Fibers Products, References 207-1W-l,St.Paul,MN55144-1 [13 John R, Rigling B. Effect of height to width ratio on K and CMOD solutions for a single edge cracked geometry with lamped specimen ends. Eng Frac Mech 60(2): 147-1997: 56 Ceram Soc1996:79(1):266-74. [14 Hartman GA, Buchanan DJ. Methodologies for thermal and 2 Tu wC, Lange FF, Evans AG. Concept for a damage-tolerant mechanical testing of TMC materials. In: Characterization of ceramic composite with"strong"interfaces. J Am Ceram Soc fibre reinforced titanium matrix composites. 77th Meeting of the 1996:79(2):417-24 AGARD Structures and Materials Panel, AGARD Report 796, B Levi CG, Yang JY, Dalgleish BJ, Zok FW, Evans AG. Proces- ordeaux. france sing and performance of an all-oxide ceramic composite. J Am [15 Hartman DA, Russ SM. Techniques for mechanical and thermal Ceram Soc I998:81(8):2077-86 4 Zawada LP, Hay RS, Lee Ss, Staehler J, Characterization and editing of Ti3Al/SCS-6 metal matrix composites. In: Johnson wS, or. Metal matrix composites: testing, analysis, and failure high temperature mechanical behavior of an oxide/oxide compo- modes, ASTM STP 1032. Philadelphia, PA: American Society for site. submitted for publication J Am Ceram Soc Testing and Materials, 1989.fracture specimen correlated well with both the length of the continuous surface matrix crack, and the extent of the matrix cracking away from the crack plane. At both 23 and 950
C, the extent of matrix cracking extended beyond the 0
fiber failure locations. Thus, good correla￾tion between the ultrasonic C-scans and extent of matrix cracking indicated C-scans can be used effectively to monitor damage progression from notches in oxide/ oxide CMC. Acknowledgements This research was conducted at the Materials and Manufacturing Directorate, Air Force Research Labora￾tory (AFRL/MLLN), Wright-Patterson Air Force Base, OH 45433-7817. The NDE facilities were provided by the NDE Branch of AFRL (AFRL/MLLP). V.A.K. was supported in part by the Dayton Area Graduate Studies Institute (DAGSI) and in part by AFOSR/AASERT Program (Contract No. F49620-95-1-0500). References [1] Lu TJ. Crack branching in all-oxide ceramic composites. J Am Ceram Soc 1996;79(1):266–74. [2] Tu WC, Lange FF, Evans AG. Concept for a damage-tolerant ceramic composite with ‘‘strong’’ interfaces. J Am Ceram Soc 1996;79(2):417–24. [3] Levi CG, Yang JY, Dalgleish BJ, Zok FW, Evans AG. Proces￾sing and performance of an all-oxide ceramic composite. J Am Ceram Soc 1998;81(8):2077–86. [4] Zawada LP, Hay RS, Lee SS, Staehler J, Characterization and high temperature mechanical behavior of an oxide/oxide compo￾site. submitted for publication J Am Ceram Soc. [5] Zawada LP, Lee SS. Evaluation of four CMCs for aerospace turbine engine divergent flaps and seals. Ceram Eng Sci Proc 1995;16(4):337–9. [6] Heredia FE, Spearing SM, Mackin TJ, He MY, Evans AG. Notch effects in carbon matrix composites. J Am Ceram Soc 1994;77(11):2817–27. [7] Mackin TJ, Purcell TE, He MY, Evans AG. Notch sensitivity and stress redistribution in three ceramic-matrix composites 1995; 78(7):1719–28. [8] Kramb VA, John R, Zawada LP. Notched fracture behavior of an oxide/oxide ceramic matrix composite. J Am Ceram Soc 1999; 82(11):3087–96. [9] Kramb VA. Notched fracture behavior of an oxide/oxide ceramic matrix composite. PhD thesis, University of Dayton, Department of Materials Engineering, 1999. [10] Stubbs DA, Clemons GS. Screening metal matrix composites using ultrasonic reflector plate and X-ray radiography non￾destructive evaluation techniques. In: Characterization of tita￾nium matrix composites, vol. VII—mechanical behavior and damage tolerance of TMCs, NASP Technical Memorandum 1199, 1995. [11] Stubbs DA, Clemons GS. Guidelines for standardizing the gain of ultrasonic inspection systems used to acquire ultrasonic reflec￾tor plate C-scans. In: Characterization of titanium matrix com￾posites, mechanical behavior and damage tolerance of TMCs, vol VII. NASP Technical Memorandum 1199, 1995. [12] 3M Company Product Data Sheet, 3M Ceramic Fibers Products, 3M Center-Building 207-1W-11, St. Paul, MN 55144-1000. [13] John R, Rigling B. Effect of height to width ratio on K and CMOD solutions for a single edge cracked geometry with clamped specimen ends. Eng Frac Mech 60 (2): 147– 1997:56. [14] Hartman GA, Buchanan DJ. Methodologies for thermal and mechanical testing of TMC materials. In: Characterization of fibre reinforced titanium matrix composites. 77th Meeting of the AGARD Structures and Materials Panel, AGARD Report 796, Bordeaux, France, 27–28 September 1993. [15] Hartman DA, Russ SM. Techniques for mechanical and thermal testing of Ti3Al/SCS-6 metal matrix composites. In: Johnson WS, editor. Metal matrix composites: testing, analysis, and failure modes, ASTM STP 1032. Philadelphia, PA: American Society for Testing and Materials, 1989. 1570 V.A. Kramb et al. / Composites Science and Technology 61 (2001) 1561–1570