Part A: applied scienc and manufacturing ELSEVIER Composites: Part A 30(1999)489-496 Potential application of ceramic matrix composites to aero-engine components Hisaichi Ohnabe a, Shoju Masakia Masakazu Onozuka Kaoru Miyahara. Tadashi Sasa Composite Materials Center, Aero-Engine and space Operations, Ishikawvajima-Harima Heavy Industries Co, Ltd, 3-5-1, Mukodai-cho, Tanashi-shi Tokyo 188, Japan ramic Gas Turbine Development Department, Research Institute, Ishikawajima-Harima Heay Industries Co, Lid, 3-1-15, Toyosu, Koto-ku Tokyo 135, Japan Abstract The present paper describes the potential application of ceramic matrix composites to aero-engine components by reviewing the related published papers and our experience in this field. It contains the material requirements for aero-engines, trends in aero-engine materials use, Japanese projects related to ceramic matrix composites( CMCs) and potential application of CMCs engines, such as combustors, nozzle faps, bladed disks and others. From the point of application to aero-engines, the remaining research and development issues are discussed to some extent. Material developments, particularly of the interface and fibers for high temperature, are still required and stressed @1999 Elsevier Science Ltd. All rights reserved Keywords: A Ceramic matrix composites(CMCs); Jet engine components 1. Introduction CMCs has also been done by P.J. Lamicq and J.F. Jamet Ceramic matrix composites(CMCs)are among advanced The authors have discussed the present status and some materials that have been identified as a key material system future prospects of advanced materials including compo- for improving the thrust-to-weight ratio of high-perfor- sites applied to aero-engines [11]. In this study, recent mance aircraft engines. CMCs are increasingly results obtained in the research and development programs considered by gas turbine designers in the USA of CMC are introduced and discussed in detail, paying parti Europe [3, 4] and Japan [5-7 for rotating as well as cular attention to activities in Japan components. The typical projects related to gas turbines are Integrated High Performance Turbine Engine Technology (IHPTET)[I], High Speed Civil Transport(HSCT) propul 2. Requirements for aero-engines sion system in High Speed Research(HSR)[8, Continuous Fiber Ceramic Composite(CFCC) Program [2] in the USA The requirements for aero-engines are high performance, and the "Novel Oxide Ceramic Composites project [3, 4 light weight, low emission and noise, and low life cycle cost. It is necessary to increase the thrust-to-weight ratio founded by the Commission of the European Community (T/W)in aero-engines, that is, to increase performance it CEC)in Europe and Research Institute of Advanced Mate- rial Gas Generator(AMG)[6] in Japan is necessary to increase turbine inlet temperature (TIT) J. Garnier et al. [9] has provided a review of two CMC Fig. I shows the trends of TIT in jet engines fabrication processes using gas phase chemical vapor infil For super-sonic and hyper-sonic transportation and space tration(CVI) for silicon carbide matrix consolidation and planes, there are different requirements for the subsonic the DIMOX directed metal oxidation growth from a liquid transportations [8]. The highest operating temperatures metal/gas reaction for aluminum oxide matrix formation. occur at takeoff and during cruise portion of the mission An overview of the French experience for thermostructural enced for hours instead of the minutes during takeoff in existing subsonic aircraft. So creep resistance is needed in Corresponding author. Now at: Department of Biocybernetics, Faculty all hot section components. High temperature materials are of Engineering, Niigata University, 8050 Ikarashi 2 no-cho, Niigata 950- also required for the low-emissions combustor and for the 2181, Japan.Tel.:+81-25-262-785;fax:+8l-25-262-7785 noise suppressor nozzle 1359-835X/99/S- see front matter @1999 Elsevier Science Ltd. All rights reserved P:S1359-835X(98)00139-0
Potential application of ceramic matrix composites to aero-engine components Hisaichi Ohnabea,*, Shoju Masakia , Masakazu Onozukaa , Kaoru Miyaharab , Tadashi Sasab a Composite Materials Center, Aero-Engine and Space Operations, Ishikawajima-Harima Heavy Industries Co., Ltd., 3-5-1, Mukodai-cho, Tanashi-shi, Tokyo 188, Japan b Ceramic Gas Turbine Development Department, Research Institute, Ishikawajima-Harima Heavy Industries Co., Ltd., 3-1-15, Toyosu, Koto-ku, Tokyo 135, Japan Abstract The present paper describes the potential application of ceramic matrix composites to aero-engine components by reviewing the related published papers and our experience in this field. It contains the material requirements for aero-engines, trends in aero-engine materials use, Japanese projects related to ceramic matrix composites (CMCs) and potential application of CMCs to aero-engines, such as combustors, nozzle flaps, bladed disks and others. From the point of application to aero-engines, the remaining research and development issues are discussed to some extent. Material developments, particularly of the interface and fibers for high temperature, are still required and stressed. q 1999 Elsevier Science Ltd. All rights reserved. Keywords: A. Ceramic matrix composites (CMCs); Jet engine components 1. Introduction Ceramic matrix composites (CMCs) are among advanced materials that have been identified as a key material system for improving the thrust-to-weight ratio of high-performance aircraft engines. CMCs are increasingly being considered by gas turbine designers in the USA [1,2], Europe [3,4] and Japan [5–7] for rotating as well as static components. The typical projects related to gas turbines are Integrated High Performance Turbine Engine Technology (IHPTET) [1], High Speed Civil Transport (HSCT) propulsion system in High Speed Research (HSR) [8], Continuous Fiber Ceramic Composite (CFCC) Program [2] in the USA and the ‘Novel Oxide Ceramic Composites’ project [3,4] founded by the Commission of the European Community (CEC) in Europe and Research Institute of Advanced Material Gas Generator (AMG) [6] in Japan. J. Garnier et al. [9] has provided a review of two CMC fabrication processes using gas phase chemical vapor infiltration (CVI) for silicon carbide matrix consolidation and the DIMOXe directed metal oxidation growth from a liquid metal/gas reaction for aluminum oxide matrix formation. An overview of the French experience for thermostructural CMCs has also been done by P.J. Lamicq and J.F. Jamet [10]. The authors have discussed the present status and some future prospects of advanced materials including composites applied to aero-engines [11]. In this study, recent results obtained in the research and development programs of CMC are introduced and discussed in detail, paying particular attention to activities in Japan. 2. Requirements for aero-engines The requirements for aero-engines are high performance, light weight, low emission and noise, and low life cycle cost. It is necessary to increase the thrust-to-weight ratio (T/W) in aero-engines, that is, to increase performance it is necessary to increase turbine inlet temperature (TIT). Fig. 1 shows the trends of TIT in jet engines. For super-sonic and hyper-sonic transportation and space planes, there are different requirements for the subsonic transportations [8]. The highest operating temperatures occur at takeoff and during cruise portion of the mission cycle, and the most severe engine conditions are experienced for hours instead of the minutes during takeoff in existing subsonic aircraft. So creep resistance is needed in all hot section components. High temperature materials are also required for the low-emissions combustor and for the noise suppressor nozzle. Composites: Part A 30 (1999) 489–496 1359-835X/99/$ - see front matter q 1999 Elsevier Science Ltd. All rights reserved. PII: S1359-835X(98)00139-0 * Corresponding author. Now at: Department of Biocybernetics, Faculty of Engineering, Niigata University, 8050 Ikarashi 2 no-cho, Niigata 950- 2181, Japan. Tel.: 1 81-25-262-7785; fax: 1 81-25-262-7785
H. Ohmabe et al /Composites: Part A 30(1999)489-496 2100 2000 SST/HST 三出 (V2500) (RJ500) 1500 FJR710■ HI-17 F3-30 1300 J3-1B 1945 1965 1975 1985 1995 Fig. 1. Trends of TIT in a jet engine [5] 3. Trends in aero-engine materials use in Fig. I is reached by the introduction of thermal barrie coating(TBC)and cooling of the blades by air One of the scenarios for penetration of advanced materi- Then, as for CMC, it will contribute to raise the TIt als is represented in Fig. 2. The percentage weight of CMCs above superalloys with coating drastically and elimination is forecast 5-6% by the year 2010 of cooling air can contribute performance increases Fig 3 shows the trends in development of high tempera- course overall system benefit should be considered ture materials for gas turbine blades. Though many mono- for the successful implementation of CMCs into aero- lithic ceramics materials exhibit intrinsic properties, the engines principal problem relative to their use in aero-engines has been their flaw sensitivity and brittle fracture modes Continuous fiber CMCs are very interesting materials due to(i their high temperature performance compared with 4. Japanese national projects related to CMC uper alloys and (ii)their higher fracture toughness development compared with monolithic ceramics in aero-engines, in which structural integrity is most required. For that reason, CMC-related projects in Japan include AMG, Sup CMCs are potential materials to meet these aero-engine Hypersonic Transport Propulsion System(HYPR), Ceramic requirements in general Gas Turbine(CGT)[13], International Co-operative Study Since the maximum use temperature for the super alloys on Analytical Technique Development of Advanced Mate is about 1000.C, the material temperature above this value rial Characteristics based on Smart Modeling (VAMAS) STEEL NICKEL CARBON FBRE COMPOSTE TITANIUM TI ALUMINIDE 1960 2000 010 Fig. 2. Trends in civil gas turbine material usage [12]
3. Trends in aero-engine materials use One of the scenarios for penetration of advanced materials is represented in Fig. 2. The percentage weight of CMCs is forecast 5–6% by the year 2010. Fig. 3 shows the trends in development of high temperature materials for gas turbine blades. Though many monolithic ceramics materials exhibit intrinsic properties, the principal problem relative to their use in aero-engines has been their flaw sensitivity and brittle fracture modes. Continuous fiber CMCs are very interesting materials due to (i) their high temperature performance compared with super alloys and (ii) their higher fracture toughness compared with monolithic ceramics in aero-engines, in which structural integrity is most required. For that reason, CMCs are potential materials to meet these aero-engine requirements in general. Since the maximum use temperature for the super alloys is about 10008C, the material temperature above this value in Fig. 1 is reached by the introduction of thermal barrier coating (TBC) and cooling of the blades by air. Then, as for CMC, it will contribute to raise the TIT above superalloys with coating drastically and elimination of cooling air can contribute performance increases. Of course, overall system benefit should be considered for the successful implementation of CMCs into aeroengines. 4. Japanese national projects related to CMC developments CMC-related projects in Japan include AMG, Super/ Hypersonic Transport Propulsion System (HYPR), Ceramic Gas Turbine (CGT) [13], International Co-operative Study on Analytical Technique Development of Advanced Material Characteristics based on Smart Modeling (VAMAS) 490 H. Ohnabe et al. / Composites: Part A 30 (1999) 489–496 Fig. 1. Trends of TIT in a jet engine [5]. Fig. 2. Trends in civil gas turbine material usage [12]
H. Ohnabe et al /Composites: Part A 30(1999)489-490 uau IMC(TiAn) NOTES t Ni Alloy Mc Inter-Metallic Compound MMC Ti Alloys eel 1990 2000 2010 2020 Fig. 3. Trends in development of high temperature materials for turbine components. [ 14] and the World Energy Net-Work (WE-NET) Project. 5. Potential application of CMCs to aero-engines They are shown in Fig. 4. It should be noted that they are not all gas turbine specific Besides offering higher temperature capability and elim- Of these, the project with direct relevance to aero-engines inating cooling requirements, CMCs offer a significant is AMG. However, the potential applications of the AMG weight reduction. Fig. 5 shows potential applications of project also include land and marine gas turbines/gas CMCs, as non-structural and structural parts of aero-engine components(referring to the engine layout [15D) SUPER ALLOYS SC ODS, PW RIMCOF (1) COMPOSITE MATERIALSκ RIMCOF FNCERAM|CSLHCcMcEAPc(42) 匚 NC TiAlNb--bas /C LCERAMICS, CHC CGT(+3) SC PM. ODS, MNG, C/C, CM EsC, TBC/ODS, CMC CC.WE-NET(47) YEAR ITUTE FOR METALS COMPOSITES FOR FUTURE INDUSTRIES NG RESEARCH ASSOCIATION FOR HIGH PERFORMANCE CERAMICS CERAMIC GAS TURBINE NGINEERING RESEARCH ASSOCIATION FOR SUPER/HYPER-SONIC * 5)VERSAILLES PROJECT ON ADVANCED MATER IALS AND STANDARDS (#6)RESEAR( UTE OF ADVANCED MATER IALS GAS-GENERATOR (7)WORLD ENERGY NET-WORK Fig 4. Japanese national projects for CMC development
[14] and the World Energy Net-Work (WE-NET) Project. They are shown in Fig. 4. It should be noted that they are not all gas turbine specific. Of these, the project with direct relevance to aero-engines is AMG. However, the potential applications of the AMG project also include land and marine gas turbines/gas generators. 5. Potential application of CMCs to aero-engines Besides offering higher temperature capability and eliminating cooling requirements, CMCs offer a significant weight reduction. Fig. 5 shows potential applications of CMCs, as non-structural and structural parts of aero-engine components (referring to the engine layout [15]). H. Ohnabe et al. / Composites: Part A 30 (1999) 489–496 491 Fig. 3. Trends in development of high temperature materials for turbine components. Fig. 4. Japanese national projects for CMC development
H. Ohnabe et al /Composites: Part A 30(1999)489-496 High Temperature Combustor liner Transition Duct Acoustic Liners 5.1. Blisk(bladed disk) 22 mm) was tested at room temperature in a spin test rig and showed almost the same strength as a thin SiC/Sic disk Blisk(rotating parts)design is driven strongly by the f=5 mm). The disks before and after the test are shown in strength/density ratio differing with static components. Figs. 8 and Lightweight blisks permit additional weight to be removed The dimensions of the above disk are: 210-134 mm reducing shaft loads, bearing compartment loads, and t=22 mm, fiber distribution: 0, 2=0.6: 1.0: 0. 17, volume others. This cascade of impacts can result in system benefits fraction,V6 is 0.32 and density is 1.97g cm. The burs that are much greater than for the individual CMC applica- speed was 32 800 rev min [18]. A 3-D bladed disc is now tions. The present manufacturing process [16, 17] is shown under development in the AMG project [191 The mechanical behavior of a continuous fiber SiC (Nica- Following the above manufacturing process, continu- lon, Nippon Carbon, Japan ) SIC (Du Pont) rotating disk was ous Si-Ti-C-O Tyranno"(Ube Industries, Japan) fiber also investigated by test and finite element analysis, taking reinforced SiC matrix composites were developed. Their into account the effect of the material's non-linear stress- stress-strain curves for 3-D CMC densified by chemical strain relationship. For the two geometries spin- vapor infiltration(CVI) followed by polymer impregna- measured and predicted strain histories showed good tion and pyrolysis(PIP)is shown in Fig. 7. The maxi- lation Burst testing and analysis revealed an excellent abil- mum tensile strength was almost 500 MPa at room ity of the material to redistribute stresses up to a mean temperature equivalent to the ultimate tensile strength. Mean hoop Disks of three dimens woven fabrics, using contin- stressand to a lesser extent, 'peak strain based burst uous Si-Ti-C-O Tyranno"(LOX-M grade), were densi- criteria show consistency between the two geometries of fied by CVI followed by PIP. A thick SiC/SiC disk(t= the disk [20 Machining CVI atment And Pyrolyse Fig. 6. CMC blisk manufacturing process
5.1. Blisk (bladed disk) Blisk (rotating parts) design is driven strongly by the strength/density ratio differing with static components. Lightweight blisks permit additional weight to be removed, reducing shaft loads, bearing compartment loads, and others. This cascade of impacts can result in system benefits that are much greater than for the individual CMC applications. The present manufacturing process [16,17] is shown in Fig. 6. Following the above manufacturing process, continuous Si–Ti–C–O Tyrannoe (Ube Industries, Japan) fiber reinforced SiC matrix composites were developed. Their stress–strain curves for 3-D CMC densified by chemical vapor infiltration (CVI) followed by polymer impregnation and pyrolysis (PIP) is shown in Fig. 7. The maximum tensile strength was almost 500 MPa at room temperature. Disks of three dimensionally woven fabrics, using continuous Si–Ti–C–O Tyrannoe (LOX-M grade), were densi- fied by CVI followed by PIP. A thick SiC/SiC disk (t 22 mm) was tested at room temperature in a spin test rig and showed almost the same strength as a thin SiC/SiC disk (t 5 mm). The disks before and after the test are shown in Figs. 8 and 9. The dimensions of the above disk are: f 210–134 mm, t 22 mm, fiber distribution r: u, z 0.6:1.0:0.17, volume fraction, Vf, is 0.32 and density is 1.97 g cm23 . The burst speed was 32 800 rev min21 [18]. A 3-D bladed disc is now under development in the AMG project [19]. The mechanical behavior of a continuous fiber SiC (Nicalon, Nippon Carbon, Japan)/SiC (Du Pont) rotating disk was also investigated by test and finite element analysis, taking into account the effect of the material’s non-linear stress– strain relationship. For the two geometries spin-tested, measured and predicted strain histories showed good correlation. Burst testing and analysis revealed an excellent ability of the material to redistribute stresses up to a mean equivalent to the ultimate tensile strength. ‘Mean hoop stress’ and to a lesser extent, ‘peak strain’ based burst criteria show consistency between the two geometries of the disk [20]. 492 H. Ohnabe et al. / Composites: Part A 30 (1999) 489–496 Fig. 5. Potential applications of CMCs. Fig. 6. CMC blisk manufacturing process
H. Ohnabe et al/Composites: Part A 30(1999)489-490 Fig. 7. Stress-strain curves of 3-D CMC [16, 17 5.2. Nozzle fap Orthogonal 3-D woven SiC polymer derived fibers were consolidated with SiC matrix by the combined process of CVI and PIP. As a result, the weight was reduced to 50% for the present super alloy components and 23% for the seal flap. The demonstrator engine test(Fig. 10), performed for over 30 h at sea level condition showed satisfactory results Fig 9. Fracture mode of 3-D disk(t= 22 mm). Environmental degradation of CMC nozzle flaps after the ngine test was evaluated in terms of the elastic modulus by a newly developed non-destructive inspection technique using impact sound [22, 231 5.3 Exhaust nozzle pts in SST/HST employ eject suppressers. Mixer ejector nozzle devices in scale have been developed for the target to reduce the noise level equivalent to ICAO Annex 16 Chapter 3 regulation with minimum thrust losses. Porous Al2O3 with the incorporation of up to 10% of Sic whiskers was applied to the acoustic linear [24] 5.4 Combust The prototype CMC liner was fabricated by means of filament winding(FW) and PIP in the AMG project(Fig 11)[25]. Si-Ti-C-O fiber and Sic and glass matrix were combined. Small scale CMC ram combustor liner pieces were also fabricated on trial from csic and sicsic and evaluated in the HYPR project [26 The CFCC combustor model parts were also fabricated cess[27] 5.5. Turbine nozzle vane Turbine nozzle vanes have complicated shapes. Research Fig. 8. 3-D disk specimen(I n shape forming is being carried out with slip-casting/Hip
5.2. Nozzle flap Orthogonal 3-D woven SiC polymer derived fibers were consolidated with SiC matrix by the combined process of CVI and PIP. As a result, the weight was reduced to 50% for the present super alloy components and 23% for the seal flap. The demonstrator engine test (Fig. 10), performed for over 30 h at sea level condition showed satisfactory results [21]. Environmental degradation of CMC nozzle flaps after the engine test was evaluated in terms of the elastic modulus by a newly developed non-destructive inspection technique using impact sound [22,23]. 5.3. Exhaust nozzle Exhaust nozzle concepts in SST/HST employ ejector suppressers. Mixer ejector nozzle devices in scale have been developed for the target to reduce the noise level equivalent to ICAO Annex 16 Chapter 3 regulation with minimum thrust losses. Porous Al2O3 with the incorporation of up to 10% of SiC whiskers was applied to the acoustic linear [24]. 5.4. Combustor The prototype CMC liner was fabricated by means of filament winding (FW) and PIP in the AMG project (Fig. 11) [25]. Si–Ti–C–O fiber and SiC and glass matrix were combined. Small scale CMC ram combustor liner pieces were also fabricated on trial from C/SiC and SiC/SiC and evaluated in the HYPR project [26]. The CFCC combustor model parts were also fabricated by slurry impregnation and a subsequent reaction sintering process [27]. 5.5. Turbine nozzle vane Turbine nozzle vanes have complicated shapes. Research on shape forming is being carried out with slip-casting/Hip H. Ohnabe et al. / Composites: Part A 30 (1999) 489–496 493 Fig. 7. Stress–strain curves of 3-D CMC [16,17]. Fig. 8. 3-D disk specimen (t 22 mm). Fig. 9. Fracture mode of 3-D disk (t 22 mm)