Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-24T08:54:38.412Z Has data issue: false hasContentIssue false

Microstructure and Indentation Fracture of Dysprosium Niobate

Published online by Cambridge University Press:  01 June 2005

Byong-Taek Lee
Affiliation:
Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
Waltraud M. Kriven*
Affiliation:
Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

The high-temperature indentation fracture and microstructures of dysprosium niobate (DyNbO4) were investigated by optical, scanning, and transmission electron microscopy (OM, SEM, and TEM). Polycrystalline samples were sintered at 1350 °C for 3 h and cut into 3 mm disks for TEM. The disks were indented in a Nikon QM (Tokyo, Japan) hot hardness indenter at room temperature up to 1000 °C. Many lamellar twins having different widths were observed by TEM as well as intergranular microcracks. The room temperature hardness was relatively low at 5.64 GPa and decreased with elevated temperatures. Crack lengths were short, showing a typical micro-cracking effect. In the sample indented at 1000 °C, dislocations in periodic arrays were evident, and their density increased markedly due to heavy plastic deformation.

Type
Articles
Copyright
Copyright © Materials Research Society 2005

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

1Garvie, R.C., Hannink, R.H.J. and Pascoe, R.T.: Ceramic Steel? Nature 258, 703 (1975).CrossRefGoogle Scholar
2Claussen, N.: Fracture toughness of Al2O3 with an unstablized ZrO2 dispersed phase. Am. Ceram. Soc. 59, 49 (1976).CrossRefGoogle Scholar
3Green, D.J., Hannink, R.H.J. and Swain, M.V.: Transformation Toughening of Ceramics (CRC Press, Boca Raton, FL, 1989).Google Scholar
4Claussen, N., Steeb, J. and Pabst, R.F.: Effect of induced microcracking on the fracture toughness of ceramics. J. Am. Ceram. Soc. Bull. 56, 559 (1977).Google Scholar
5Lee, B.T. and Hiraga, K.: Crack propagation and deformation behavior of Al2O3-24 vol. % ZrO2 composite studied by transmission electron microscopy. Mater. Res. 9, 1199 (1994).CrossRefGoogle Scholar
6Lee, B.T., Koyama, T., Nishiyama, A. and Hiraga, K.: Microstructure and fracture characteristic of Si3N4–ZrO2(MgO) ceramic composite studied by transmission electron microscopy. Scrip. Meta. et Mater. 32, 1073 (1995).CrossRefGoogle Scholar
7First, R.C. and Heuer, A.H.: Deformation twinning in single-crystal monoclinic zirconia: A first report. J. Am. Ceram. Soc. 75, 2302 (1992).CrossRefGoogle Scholar
8Kriven, W.M., Siah, L.F., Schmücker, M. and Schneider, H.: High temperature microhardness of single crystal mullite. J. Am. Ceram. Soc. 87, 970 (2004).CrossRefGoogle Scholar
9Tsunekawa, S. and Takei, H.: Study on the room temperature phase of LaNbO4. Mater. Res. Bull. 12, 1087 (1977).CrossRefGoogle Scholar
10 Powder Diffraction File Card No. 22-1125 (International Center for Diffraction Data, Newtown Square, PA, 1991).Google Scholar
11Jian, L. and Wayman, C.M.: Monoclinic-to-tetragonal phase transformation in a ceramic rare-earth orthoniobate, LaNbO4. J. Am. Ceram. Soc. 80, 803 (1997).CrossRefGoogle Scholar
12Tsunekawa, S. and Takei, H.: Twinning structure of ferroelastic LaNbO4 and NdNbO4 crystals. Phys. Status Solidi A 50, 695 (1978).CrossRefGoogle Scholar
13Jian, L. and Wayman, C.M.: Compressive behavior and domain-related shape memory effect in LaNbO4 ceramics. Mater. Lett. 26, 1 (1996).CrossRefGoogle Scholar
14Quinn, C. and Wusirika, R.: Twinning in YNbO4 J. Am. Ceram. Soc. 74 [2], 431 (1991).CrossRefGoogle Scholar
15Lee, B.T., Siah, L-F. and Kriven, W.M. Microstructure and indentation fracture of DyNbO4 studied by TEM, Presented at 26th Ann. Int. Conf. on Advanced Ceramics and Composites, Cocoa Beach, Florida, Jan. 13-18th (2002), Abstract No. ECD3-F-02-2002.Google Scholar
16Aizu, K.: Possible species of ‘ferroelastic’ crystals and of simultaneously ferroelectric and ferroelastic crystals. J. Phys. Soc. Jpn. 27, 387 (1969).CrossRefGoogle Scholar
17Aizu, K.: Possible species of ferromagnetic, ferroelectric and ferroelastic crystals. Phys. Rev. B2, 754 (1970).CrossRefGoogle Scholar
18Wadhavan, V.K.: Ferroelasticity and related properties of crystals. Phase Trans. 3, 3 (1982).CrossRefGoogle Scholar
19Wadhavan, V.K.: Ferroelasticity: Introductory survey and present status. Phase Trans. 34, 3 (1991).CrossRefGoogle Scholar
20Dudnick, E.F. and Kiosse, G.A.: The structural peculiarities of some pure ferroelastics. Ferroelectrics 48, 33 (1983).CrossRefGoogle Scholar
21Weber, H.P., Tofield, B.C. and Liao, P.F.: Ferroelastic behavior and the monoclinic-to-orthorhombic phase transition in MP5O14 (M - La-Tb). Phys. Rev. B11, 1152 (1975).CrossRefGoogle Scholar
22Virkar, A.V., Jue, J.F., Smith, P., Mehta, K. and Prettyman, K.: The role of ferroelasticity in toughening of brittle materials. Phase Trans. 35, 27 (1991).CrossRefGoogle Scholar
23Virkar, A.V. and Matsumoto, R.L.K.: Ferroelastic domain switching as a toughening mechanism in tetragonal zirconia. J. Am. Ceram. Soc. 69 C224 (1986).CrossRefGoogle Scholar
24Kriven, W.M. Twinning in structural ceramics, in Twinning in Advanced Materials, edited by Yoo, M.H. and Wuttig, M. (TMS, Warrendale, PA, 1994), pp. 435448.Google Scholar
25Gülgün, M.A. and Kriven, W.M.: A simple solution-polymerization route for oxide powder synthesis. Ceram. Trans. 62, 57 (1995).Google Scholar
26Gülgün, M.A., Kriven, W.M., and Nyugen, M.H.: Processes for preparing mixed-oxide powders, U.S. Patent No. 6482487, 19 November 2002.Google Scholar
27Siah, L.F. In situ, in air, high temperature phase transformations in RNbO4 and R2TiO5 (R - Dy and Y), using a thermal-image furnace. Ph.D. Thesis, University of Illinois—Urbana-Champaign (April 2002), pp. 1821.Google Scholar
28Lee, B.T., Chun, B.S. and Hiraga, K.: Microstructure of gas-atomized Al-20 wt% Si–1 wt% Ni powders studied by electron microscopy. J. Mater. Res. 9, 2519 (1994).CrossRefGoogle Scholar
29Lee, B.T., Hayashi, S., Hirai, T. and Hiraga, K.: Crack propagation behavior of CVD Si3N4–TiN composite examined by high-resolution electron microscopy. Mater. Trans. JIM. 34, 573 (1993).CrossRefGoogle Scholar
30Lee, B.T., Pezzotti, G. and Hiraga, K.: Microstructure and fracture behavior of SiC-platelet-reinforced Si3N4 matrix composites. Mater. Sci. Eng. A 177, 151 (1994).CrossRefGoogle Scholar
31Lee, B.T., Nishiyama, A. and Hiraga, K.: Micro-indentation fracture of ZrO2(Y2O3)–Al2O3 ceramic composites studied by micro-indentation and high-resoluion electron microscopy. Proc. ICSMA. Inter. Symp. Strength Mater. 10, 435 (1994).Google Scholar