Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-02T19:06:34.771Z Has data issue: false hasContentIssue false
  • English
  • Français

Formation of in situ reinforced microstructures in α-sialon ceramics: Part III. Static and dynamic ripening

Published online by Cambridge University Press:  03 March 2011

Hong Peng ,
Zhijian Shen  and
Mats Nygren
Hong Peng
Affiliation:
Department of Inorganic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
Zhijian Shen*
Affiliation:
Department of Inorganic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
Mats Nygren
Affiliation:
Department of Inorganic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Dual cation (Yb + Y)-stabilized α-sialon ceramics with either stoichiometric composition or nonstoichiometric composition that yield less than 3 vol% of an additional intergranular liquid/glass phase were consolidated by spark plasma sintering (SPS). This process allows very fast heating and cooling, thus providing a unique possibility to monitor and manipulate the kinetics of phase transformation and grain growth during sintering. Below a temperature threshold, full densification and complete α-sialon formation are accompanied by very limited grain growth. The grain growth kinetics were investigated both by post heat-treatment of SPS pre-consolidated monophasic α-sialon bodies consisting of sub-micron sized equiaxed grains in a conventional graphite furnace using extended holding times (hours) and directly rapid annealing in the SPS apparatus above the temperature threshold (within minutes). Post heat treatment in the graphite furnace yielded in situ reinforced microstructures consisting of interlocking elongated grains only in the presence of an additional intergranular liquid/glass phase. Direct annealing by SPS process yielded in situ reinforced microstructures whether or not an additional liquid/glass was involved. The former microstructures are formed via the static Ostwald ripening mechanism whereas the latter ones are generated via a dynamic ripening mechanism. This demonstrates that the dynamic ripening provides an efficient means of developing in situ reinforced microstructure in α-sialon ceramics with improved mechanical properties.

Keywords

SinteringCeramicMicrostructure
Type
Articles
Information
Journal of Materials Research , Volume 19 , Issue 8 , August 2004 , pp. 2402 - 2409
Copyright
Copyright © Materials Research Society 2004

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.Hwang, C.J., Susnitzky, W.D. and Beaman, D.R.: Preparation of multication α-SiAlON containing strontium. J. Am. Ceram. Soc. 78, 588 (1995).CrossRefGoogle Scholar
2.Nordberg, L-O. and Ekstrom, T.: Hot-pressed MoSi2-particulate-reinforced α-SiAlON composites. J. Am. Ceram. Soc. 78, 797 (1995).CrossRefGoogle Scholar
3.Shen, Z.J., Ekström, T. and Nygren, M.: Ytterbium-stabilized α-Sialon ceramics. J. Phys. D: Appl. Phys. 29, 893 (1996).CrossRefGoogle Scholar
4.Wang, H., Cheng, Y-B., Muddle, B.C., Gao, L. and Yen, T.S.: Preferred orientation in hot-pressed Ca α-Sialon ceramics. J. Mater. Sci. Lett. 15, 1447 (1996).CrossRefGoogle Scholar
5.Shen, Z.J., Nordberg, L.O., Nygren, M., and Ekstrom, T.: α-Sialon grains with high aspect ratio—Utopia or reality? NATO ASI Series; Series 3. High Technology. 25, edited by Babini, G.N. et al. , (Kluwer Academic Publishers, The Netherlands) (Engineering Ceramics ’96: Higher Reliability through Processing, 1997), pp. 169–178.Google Scholar
6.Chen, I-W. and Rosenflanz, A.: A tough SiALON ceramic based on α-Si3N4 with a whisker-like microstructure. Nature 389, 701 (1997).Google Scholar
7.Kim, J., Rosenflanz, A. and Chen, I-W.: Microstructure control of in-situ-toughened α-SiAlON ceramics. J. Am. Ceram. Soc. 83, 1819 (2000).CrossRefGoogle Scholar
8.Stranski, I.N. and Totomanow, D.: Rate of formation of (crystal) nuclei and the Ostwald step rule. Z. Physik. Chem. A 163, 399 (1933).CrossRefGoogle Scholar
9.Kitayama, M., Hirao, K., Toriyama, M. and Kanzaki, S.: Anistropic Ostwald ripening in β-Si3N4 with different lanthanide additives. Ceram. Trans. 83, 517 (1998).Google Scholar
10.Kitayama, M., Hirao, K., Toriyama, M. and Kanzaki, S.: Modeling and simulation of grain growth in Si3N4 I. Anisotropic Ostwald ripening. Acta Mater. 46, 6541 (1998).CrossRefGoogle Scholar
11.Shen, Z.J. and Nygren, M.: Kinetic aspects of superfast consolidation of silicon nitride based ceramics by spark plasma sintering. J. Mater. Chem. 11, 204 (2001).CrossRefGoogle Scholar
12.Kawaoka, H., Adachi, T., Sekina, T., Choa, Y.H., Gao, L. and Niihara, K.: Effect of α/β phase ratio on microstructure and mechanical properties of silicon nitride ceramics. J. Mater. Res. 16, 2264 (2001).Google Scholar
13.Shen, Z.J. and Nygren, M.: On the preparation of bio-, nano- and structural ceramics and composites by spark plasma sintering. Solid State Sci. 5, 125 (2003).Google Scholar
14.Shen, Z.J., Peng, H. and Nygren, M.: Formation of in-situ reinforced microstructure in α-sialon ceramics I: Stoichiometric oxygen-rich compositions. J. Mater. Res. 17, 336 (2002).Google Scholar
15.Peng, H., Shen, Z.J. and Nygren, M.: Formation of in-situ reinforced microstructure in α-sialon ceramics: Part II. In the Presence of a liquid phase. J. Mater. Res. 17, 1136 (2002).CrossRefGoogle Scholar
16.Shen, Z.J., Zhe, Z., Peng, H. and Nygren, M.: Formation of tough interlocking microstructures in silicon nitride ceramics by dynamic ripening. Nature 417, 266 (2002).CrossRefGoogle ScholarPubMed
17.Evans, A.G. and Charles, E.A.: Fracture toughness determinations by indentation. J. Am. Ceram. Soc. 59, 371 (1976).CrossRefGoogle Scholar
18.Werner, P-E.: A Fortran program for least-squares refinement of crystal structure cell dimensions. Arkiv för kemi. 31, 513 (1969).Google Scholar
19.Peng, H., Shen, Z.J. and Nygren, M.: Reaction sequences occurring in dense Li-doped sialon ceramics: influence of temperature and holding time. J. Mater. Chem. 13, 2285 (2003).CrossRefGoogle Scholar
20.Shen, Z.J., Peng, H. and Nygren, M.: Rapid formation and deformation of Li-doped sialon ceramics. J. Am. Ceram. Soc. 2004 (in press).CrossRefGoogle Scholar
21.Emoto, H. and Mitomo, M.: Control and characterization of abnormally grown grains in silicon nitride ceramics. J. Eur. Ceram. Soc. 17 797–804 (1997).Google Scholar
22.Shen, Z.J., Peng, H., Pettersson, P. and Nygren, M.: Self-reinforced α-sialon ceramics with improved damage tolerance developed by a new processing strategy. J. Am. Ceram. Soc. 85, 2876 (2002).CrossRefGoogle Scholar
23.Hirao, K., Hyuga, H., Yamauchi, Y., Shen, Z.J. and Nygren, M.: Wear properties of Yb α-sialon ceramics. Wear (in press).Google Scholar