Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-27T02:01:55.316Z Has data issue: false hasContentIssue false

The Influence of Microstructure on the Mechanical Behavior of Silicon Nitride Ceramics

Published online by Cambridge University Press:  25 February 2011

P. F. Becher
Affiliation:
Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge, TN
H. T. Lin
Affiliation:
Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge, TN
S. L. Hwang
Affiliation:
Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge, TN
M. J. Hoffmann
Affiliation:
Max-Planck-Institut für Metallforschung Powder Metallurgy Laboratory Stuttgart, Germany
I-Wei Chen
Affiliation:
University of MichiganDepartment of Materials Science Ann Arbor, MI
Get access

Extract

The introduction of elongated silicon nitride grains during densification in the presence of a liquid phase can impart considerable improvement to the fracture toughness. This toughening is not universally attained but depends on the activation of intergranular rather than transgranular fracture. This is reminiscent of the requirement of interfacial debonding in whiskerreinforced ceramics. In fact, additional observations such as bridging in the crack wake by elongated grains and pullout of some of these grains further suggest that the crack wake mechanisms that contribute to the toughening of whisker-reinforced ceramics can also operate in silicon nitrides containing elongated grains. Various investigators have found that, consistent with crack wake mechanisms, the fracture toughness of silicon nitrides increases with increase in the diameter of the larger elongated grains. However, little is known about the effects of the grain boundary phase(s) and their properties on the interfacial debonding/intergranular fracture in such silicon nitrides. This is critical as observations show that crack propagation in some systems exhibiting larger elongated grains occurs transgranularly and no toughening occurs.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. a.Becher, P. F., Hsueh, C. H., Angelini, P., and Tiegs, T. N., “Toughening Behavior in Whisker Reinforced Ceramic Matrix Composites,” J. Am. Ceram. Soc. 71(12) 1050–61 (1988). b. P. F. Becher, “Microstructural Design of Toughened Ceramics,” J. Am. Ceram. Soc. 74(2) 255-69 (1991). c. P. F. Becher, E. R. Fuller, Jr., and P. Angelini, “Matrix-Grain-Bridging Contributions to the Toughening of Whisker-Reinforced Ceramics,” J. Am. Ceram. Soc. 74(9) 2131-35 (1991).Google Scholar
2. Budiansky, B., Hutchinson, J. W., and Evans, A. G., “Matrix Fracture in Fiber- Reinforced Ceramics,” J. Mech. Phys. Solids 34(2) 167–89 (1986).Google Scholar
3. a.Cook, R. F., “Segregation Effects in the Fracture of Brittle Materials: Ca-A12O3 ,” Acta Metall. 38(6) 10831100 (1990). b. S. T. Bennison and B. R. Lawn, "Role of Interfacial Grain-Bridging Friction in the Crack-Resistance and Strength Properties of Nontransforming Ceramics," Acta Metall. 37(10) 2659-71 (1989).Google Scholar
4. a.Lange, F. F., “Fracture Toughness of Si3N4 as a Function of the Initial a-Phase Content,” J. Am. Ceram. Soc. 62 (7-8) 428–30 (1979). b. C. W. Li and J. Yamanis, "Super-Tough Silicon Nitride with R-Curve Behavior," Ceram. Sci. and Engr Proc., 10 (7-8) 632-45 (1989).Google Scholar
5. a.Alexander, K. B., Becher, P. F., and Waters, S. B., “Characterization of Silicon Carbide Platelet-Reinforced Alumina,” pp. 106–7 in Proc. 12th Int'l Congress for Electron Microscopy, San Francisco Press, San Francisco, CA, 1990. b. S. M. Ketchion, G. Leng-Ward, and M. H. Lewis, "SiC Dispersoid-Reinforced Si3N4 Composites," pp. 757-63 in Ceramic Trans., Vol. 19, M. D. Sacks (ed.), Am. Ceram. Soc., Westerville, OH. 1990.Google Scholar
6. Vekinis, G., Ashby, M. F., and Beaumont, P. W. R., “R-Curve Behavior of A120 3 Ceramics,” Acta Metall. Mater. 38(6) 1151–62 (1990).Google Scholar
7. Kawashima, T., Okamoto, H., Yamamoto, H., and Kitamura, A., “Grain Size Dependence of the Fracture Toughness of Silicon Nitride Ceramics,” J. Ceram. Soc. Japan, 99: 14, (1991).Google Scholar
8. Mitomo, M., “Toughening of Silicon Nitride Ceramics By Microstructural Control,” pp. 101–07 in Proc. Sci. Eng'g Ceram., Kimura, S. & Niihara, K., eds., Ceram. Soc. Jpn, Tokyo, 1991.Google Scholar
9. Tien, T. Y., “Silicon Nitride Ceramics-Alloy Design,” lectures at Max-Planck-Institut, Institut für Metallforschung, Stuttgart, Germany.Google Scholar
10. Tajima, Y., Urashima, K., Watanabe, M., and Matsuo, Y., “Fracture Toughness and Microstructure Evaluation of Silicon Nitride Ceramics,” pp. 1034–41 in Ceramic Transactions, Vol. 1: Ceramic Powder Science-IIB, Messing, G. L., Fuller, E. R. Jr., and Hausner, H. (editors), Am. Ceram. Soc., Westerville, OH, 1988.Google Scholar
11. Rühle, M., Kleebe, H. J., Cannon, R. M., and Clarke, D. R., “Atomistic Structure and Composition of Grain Boundaries in Silicon Nitride Ceramics,” this volume.Google Scholar
12. Pyzik, A. J. and Beaman, D. R., “Self-Reinforced Silicon Nitride,” to be published.Google Scholar
13. Rice, R. W., “Microstructure Dependence of Mechanical Behavior of Ceramics,” Treatise Mat. Sci. Tech., 11:199381 (1977).Google Scholar
14. Petzow, G. and Hoffmann, M. J., “Grain Growth Studies in Si3N4-Ceramics,” pp. 91102 in Materials Science Forum, Vols. 113–115, Trans. Tech. Publns, Switzerland, 1993.Google Scholar
15. Freiman, S. W., “Effect of Environment on the Fracture of Ceramics,” Ceramurgia, 2:111–18 (1976).Google Scholar
16. Quinn, G. D., “Review of Static Fatigue in Silicon Nitride and Silicon Carbide,” Ceram. Eng. Sci. Proc. 3(1-2) 7798 (1982).Google Scholar
17. Dauskardy, R. H., Yao, D., Dalgleish, B. J., Becher, P. F., and Ritchie, R. O., “Cyclic Fatigue-Crack Growth in a Silicon Carbide Whisker-Reinforced Alumina Composite: Role of Load Ratio,” to be published.Google Scholar
18. Lin, C. K. J., Jenkins, M. G., and Ferber, M. K., “Evaluation of Tensile Static, Dynamic, and Cyclic Fatigue Behavior for a HIPed Silicon Nitride at Elevated Temperatures,” this volume.Google Scholar