logo

SCIENCE CHINA Technological Sciences, Volume 62 , Issue 8 : 1349-1356(2019) https://doi.org/10.1007/s11431-018-9501-1

An experimental study of ultra-high temperature ceramics under tension subject to an environment with elevated temperature, mechanical stress and oxygen

More info
  • ReceivedDec 13, 2018
  • AcceptedMar 21, 2019
  • PublishedJul 11, 2019

Abstract

Ultra-high temperature ceramic (UHTC) composites are widely used in high-temperature environments in aerospace applications. They experience extremely complex environmental conditions during service, including thermal, mechanical and chemical loading. Therefore, it is critical to evaluate the mechanical properties of UHTCs subject to an environment with elevated temperature, mechanical stress and oxygen. In this paper, an experimental investigation of the uniaxial tensile properties of a ZrB2-SiC-graphite subject to an environment with a simultaneously elevated temperature, mechanical stress and oxygen is conducted based on a high-temperature mechanical testing system. To improve efficiency, an orthogonal experimental design is used. It is suggested that the temperature has the most important effect on the properties, and the oxidation time and stress have an almost equal effect. Finally, the fracture morphology is characterized using scanning electron microscopy (SEM), and the mechanism is investigated. It was concluded that the main fracture mode involved graphite flakes pulling out of the matrix and crystalline fracture, which indicates the presence of a weak interface in the composites.


Funded by

the National Natural Science Foundation of China(Grant,Nos.,11472092,11672088,11502058)

and the National Basic Research Program of China(Grant,No.,2015CB655200)


Acknowledgment

This work was supported by the National Natural Science Foundation of China (Grant Nos. 11472092, 11672088, 11502058), and the National Basic Research Program of China (Grant No. 2015CB655200).


References

[1] Yang Y, Yang J, Fang D. Research progress on thermal protection materials and structures of hypersonic vehicles. Appl Math Mech-Engl Ed, 2008, 29: 51-60 CrossRef Google Scholar

[2] Wuchina E, Opila E, Opeka M, et al. UHTCs: Ultra-high temperature ceramic materials for extreme environment applications. Electrochem Soc Interface, 2007, 16: 30. Google Scholar

[3] Monteverde F, Bellosi A, Scatteia L. Processing and properties of ultra-high temperature ceramics for space applications. Mater Sci Eng-A, 2008, 485: 415-421 CrossRef Google Scholar

[4] Upadhya K, Yang J M, Hoffman W P. Advanced materials for ultrahigh temperature structural applications above 2000°C. Am Ceram Soc Bull, 1997, 76: 51–56. Google Scholar

[5] Tandon R, Dumm H P, Corral E L, et al. Ultra high temperature ceramics for hypersonic vehicle applications. Sandia National Laboratories, 2006. Google Scholar

[6] Guo S Q. Densification of ZrB2-based composites and their mechanical and physical properties: A review. J Eur Ceramic Soc, 2009, 29: 995-1011 CrossRef Google Scholar

[7] Zimmermann J W, Hilmas G E, Fahrenholtz W G, et al. Thermophysical properties of ZrB2 and ZrB2-SiC ceramics. J Am Ceramic Soc, 2008, 91: 1405-1411 CrossRef Google Scholar

[8] Opeka M M, Talmy I G, Wuchina E J, et al. Mechanical, thermal, and oxidation properties of refractory hafnium and zirconium compounds. J Eur Ceramic Soc, 1999, 19: 2405-2414 CrossRef Google Scholar

[9] Fahrenholtz W G, Hilmas G E, Talmy I G, et al. Refractory diborides of zirconium and hafnium. J Am Ceramic Soc, 2007, 90: 1347-1364 CrossRef Google Scholar

[10] Rahman M, Wang C C, Chen W, et al. Electrical resistivity of titanium diboride and zirconium diboride. J Am Ceramic Soc, 1995, 78: 1380-1382 CrossRef Google Scholar

[11] Mishra (Pathak) S K, Das S, Das S K, et al. Sintering studies on ultrafine ZrB2 powder produced by a self-propagating high-temperature synthesis process. J Mater Res, 2000, 15: 2499-2504 CrossRef ADS Google Scholar

[12] Opeka M M, Talmy I G, Zaykoski J A. Oxidation-based materials selection for 2000°C+hypersonic aerosurfaces: Theoretical considerations and historical experience. J Mater Sci, 2004, 39: 5887-5904 CrossRef ADS Google Scholar

[13] Chamberlain A L, Fahrenholtz W G, Hilmas G E, et al. High-strength zirconium diboride-based ceramics. J Am Ceramic Soc, 2004, 87: 1170-1172 CrossRef Google Scholar

[14] Rezaie A, Fahrenholtz W G, Hilmas G E. Effect of hot pressing time and temperature on the microstructure and mechanical properties of ZrB2-SiC. J Mater Sci, 2007, 42: 2735-2744 CrossRef ADS Google Scholar

[15] Watts J, Hilmas G, Fahrenholtz W G. Mechanical characterization of ZrB2-SiC composites with varying SiC particle sizes. J Am Ceramic Soc, 2011, 94: 4410–4418. Google Scholar

[16] Wang Z, Hong C, Zhang X, et al. Microstructure and thermal shock behavior of ZrB2-SiC-graphite composite. Mater Chem Phys, 2009, 113: 338-341 CrossRef Google Scholar

[17] Zhou S, Wang Z, Zhang W. Effect of graphite flake orientation on microstructure and mechanical properties of ZrB2-SiC-graphite composite. J Alloys Compd, 2009, 485: 181-185 CrossRef Google Scholar

[18] Zhang X, Wang Z, Sun X, et al. Effect of graphite flake on the mechanical properties of hot pressed ZrB2-SiC ceramics. Mater Lett, 2008, 62: 4360-4362 CrossRef Google Scholar

[19] Wang Z, Wang S, Zhang X, et al. Effect of graphite flake on microstructure as well as mechanical properties and thermal shock resistance of ZrB2-SiC matrix ultrahigh temperature ceramics. J Alloys Compd, 2009, 484: 390-394 CrossRef Google Scholar

[20] Wang L, Liang J, Fang G. High temperature fracture behavior of ZrB2SiC-graphite composite in vacuum and air. J Alloys Compd, 2015, 619: 145-150 CrossRef Google Scholar

[21] Chen H, Wang Z, Meng S, et al. The failure mechanism of ZrB2-SiC-graphite composite heated by high electric current. Mater Lett, 2009, 63: 2346-2348 CrossRef Google Scholar

[22] Zhi W, Zhanjun W, Guodong S. Effect of annealing treatment on mechanical properties of a ZrB2-SiC-graphite ceramic. Mater Sci Eng-A, 2011, 528: 2870-2874 CrossRef Google Scholar

[23] Zhi W, Qiang Q, Zhanjun W, et al. Effect of oxidation at 1100°C on the strength of ZrB2-SiC-graphite ceramics. J Alloys Compd, 2011, 509: 6871-6875 CrossRef Google Scholar

[24] Jin H, Meng S, Zhang X, et al. Effects of oxidation temperature, time, and ambient pressure on the oxidation of ZrB2-SiC-graphite composites in atomic oxygen. J Eur Ceramic Soc, 2016, 36: 1855-1861 CrossRef Google Scholar

[25] ASTM: C1366-97: Standard Test Method for Tensile Strength of Monolithic Advanced Ceramics at Elevated Temperatures. ASTM International. West Conshohocken, 1997. Google Scholar

[26] ASTM: C1273-95a: Standard Test Method for Tensile Strength of Monolithic Advanced Ceramics at Ambient Temperatures. ASTM International. West Conshohocken, 2000. Google Scholar

  • Figure 1

    (Color online) The UHTC uniaxial tensile specimens. (a) Diagram of specimen; (b) the real specimens; (c) SEM observation on the surface after polishing.

  • Figure 2

    (Color online) High-temperature grip. (a) Top view; (b) side view.

  • Figure 3

    (Color online) Copper induction coil. (a) Side view; (b) top view.

  • Figure 4

    (Color online) High-temperature mechanical property testing system. (a) Schematic diagram; (b) real testing system; (c) electromagnetic induction heating apparatus.

  • Figure 5

    (Color online) Comparison of the strength at high temperatures and room temperature.

  • Figure 6

    Range analysis results.

  • Figure 7

    (Color online) Macroscale fracture morphology.

  • Figure 8

    (Color online) Fracture morphology in different cases. (a) 800°C-5 min-0 MPa; (b) 800°C-10 min-60 MPa; (c) 800°C-30 min-30 MPa; (d) 1000°C-5 min-60 MPa; (e) 1000°C-10 min-30 MPa; (f) 1000°C-30 min-0 MPa; (g) 1200°C-5 min-30 MPa; (h) 1200°C-10 min-0 MPa; (i) 1200°C-30 min-60 MPa.

  • Table 1   Different levels of three factors

    Level

    Temperature (°C)

    Stress (MPa)

    Time (min)

    1

    800

    0

    5

    2

    1000

    30

    10

    3

    1200

    60

    30

  • Table 2   Orthogonal experimental design

    Run-ID

    Experimental error

    Temperature (°C)

    Stress (MPa)

    Time (min)

    1

    1

    1 (800)

    1 (0)

    1 (5)

    2

    1

    2 (1000)

    2 (30)

    2 (10)

    3

    1

    3 (1200)

    3 (60)

    3 (30)

    4

    2

    1 (800)

    2 (30)

    3 (30)

    5

    2

    2 (1000)

    3 (60)

    1 (5)

    6

    2

    3 (1200)

    1 (0)

    2 (10)

    7

    3

    1 (800)

    3 (60)

    2 (10)

    8

    3

    2 (1000)

    1 (0)

    3 (30)

    9

    3

    3 (1200)

    2 (30)

    1 (5)

  • Table 3   Experimental results for different environmental conditions

    Run-ID

    1

    2

    3

    4

    5

    6

    7

    8

    9

    Average strength (MPa)

    159.9

    125.0

    101.1

    194.8

    66.4

    78.8

    125.2

    99.2

    75.9

  • Table 4   Range of different factors

    Factors

    1

    2

    3

    Range

    Experimental error

    128.69

    113.37

    100.12

    28.58

    Temperature

    160.00

    96.90

    85.28

    74.72

    Stress

    100.76

    109.71

    131.71

    30.94

    Time

    112.66

    131.93

    97.59

    34.33

  • Box 1   Testing procedure for UHTC properties in an environment with a simultaneously elevated temperature, mechanical stress and oxygen

    ƒƒ(1) Put the UHTC specimen into the grip, check the centerline of the specimen, coil and loading axis to align the specimen.

    ƒƒ(2) Check the cold-water cooling subsystem, loading controller subsystem and electromagnetic induction heating subsystem.

    ƒƒ(3) Preload the specimen to a small force value 10 N to make the specimen fixed.

    ƒƒ(4) Heat the specimen to the designated temperature, as listed in Table2.

    ƒƒ(5) Load the specimen to the designated stress at rate of 0.5 mm/min.

    ƒƒ(6) Maintain the stress and temperature for the designated time.

    ƒƒ(7) Continue to load the specimen at rate of 0.5 mm/min until failure occurs.

    ƒƒ(8) Turn off the loading and heating subsystems and save the experimental data.

Copyright 2020 Science China Press Co., Ltd. 《中国科学》杂志社有限责任公司 版权所有

京ICP备17057255号       京公网安备11010102003388号