Microstructures and Densification Behaviors of $Al_2O_3-ZrO_2(ZTA)$ Composites Fabricated by a Surface-induced Coating

표면-유기 코팅에 의해 합성한 $Al_2O_3-ZrO_2(ZTA)$ 복합체의 미세구조와 소결거동

  • 장현명 (포항공과대학교 재료공학과 정밀세라믹스 공정과학연구실) ;
  • 문종하 (포항공과대학교 재료공학과 정밀세라믹스 공정과학연구실) ;
  • 김광수 (포항공과대학교 재료공학과 정밀세라믹스 공정과학연구실)
  • Published : 1994.01.01

Abstract

Al2O3-ZrO2(ZTA) composites were fabricated by a surface-induced coating of the precursor for the ZrO2 phase on the kinetically stable colloid particles of Al2O3. The fabricated composites were characterized by a uniform spatial distribution of the dispersed ZrO2 phase and by the absence of large ZrO2 grains throughout the Al2O3 matrix. The fracture toughness (KIC) and the bending strength of ZTA composites sintered at 1$600^{\circ}C$, respectively, were 5.6 MPa.m1/2 (for 20 wt% ZrO2) and 600 MPa (for 15wt% ZrO2). The fraction of tetragonal ZrO2 phase decreases as the total content of ZrO2, suggesting that both the stress-induced tlongrightarrowm transformation and the microcrack nucleation contribute to the toughening of the ZTA composites fabricated by the surface-induced coating.

Keywords

References

  1. Fundamentals of Fracture Mechanics J.F. Knoff
  2. Fine Ceramics Structural Ceramics O. Kamigaito;S. Saito(ed.)
  3. J. Am. Ceram. Soc. v.64 no.7 Toughening of Ceramics by Circumferential Microcracking A.G. Evans;K.T. Faber
  4. J. Am. Ceram. Soc. v.67 no.4 Crack-Growth Resistance of Microcracking Brittle Materials A.G. Evans;K.T. Faber
  5. Ceram. Eng. Sci. Proc. v.5-6 Toughening Mechanism for Ceramics in Automotive Applications K.T. Faber
  6. J. Mat. Sci. v.19 Transformation Toughening, Part 1-5 F.F. Lange
  7. J. Am. Ceram. Soc. v.64 no.1 Transient Thermal Stress Behavior in ZrO₂-Toughened Al₂O₃ P.F. Becher
  8. J. Am. Ceram. Soc. v.66 no.10 Uniformity of Al₂O₃-ZrO₂Composites by Colloidal Filtration I.A. Aksay;F.F. Lange;B.I. Davis
  9. J. Am. Ceram. Soc. v.74 no.12 Effects of pH and Particle Size on the Processing of and the Development of Microstructure in Alumina-Zirconia Composites A. Bleier;C.G. Westmoreland
  10. J. Mater. Res. v.5 no.3 Homogeneous Fabrication and Densification of Zirconia-toughened Alumina(ZTA) Composite by the Surface-induced Coating H.M. Jang;J.H. Moon
  11. J. Am. Ceram. Soc. v.55 no.2 Linear Intercept Technique for Measuring Grain Size in Two-phase Polycrystalline Ceramics J.C. Wurst;J.A. Nelson
  12. Quantitative Streology Particle and Grain Size Distributions E.E. Underwood
  13. J. Am. Ceram. Soc. v.55 no.6 Phase Analysis in Zirconia Systems R.C. Garvie;P.S. Nicholson
  14. J. Mater. Sci. v.10 no.12 Equilibrium Penny-like Cracks in Indentation Fracture B.R. Lawn;E.R. Fuller
  15. Advances in Ceramis;Science and Technology of Zirconia v.3 Design of Transformation-toughened Ceramics N. Claussen;M. Ruhle;A.H. Heuer(ed.);L.W. Hobbs(ed.)