Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
권호 표지
DOI QR코드

DOI QR Code

Influence of CrO3 Sealing Treatment on Properties of Plasma Sprayed Al2O3 Coating

플라즈마 용사 Al2O3 코팅의 특성에 미치는 CrO3 봉공처리의 영향

  • Cho, Kyeong-Sik (School of Advanced Materials & System Engineering, Kumoh National Institute of Technology) ;
  • Lee, Hyun-Kwuon (School of Advanced Materials & System Engineering, Kumoh National Institute of Technology) ;
  • Kwon, Jeong-Cheol (Top Win Tech Co.)
  • 조경식 (금오공과대학교 신소재시스템공학부) ;
  • 이현권 (금오공과대학교 신소재시스템공학부) ;
  • 권정철 (제일윈텍(주))
  • Received : 2011.01.02
  • Accepted : 2011.01.10
  • Published : 2011.03.31
Download PDF
⟨ Previous Next ⟩

Abstract

Plasma sprayed ceramic coatings inherently contain pores and usually also cracks. Post-treatment of the plasma sprayed coatings is a way to close the connected pores and cracks. In this study, post-sealing treatment in plasma sprayed $Al_2O_3$ coatings was employed to overcome the reduction of coating properties. $Al_2O_3$ plasma thermal spray coating was made on aluminum alloys plate, $CrO_3$ post coating and heat treatment at $550^{\circ}C$ was carried out in order for final $Cr_2O_3$ to be saturated through phase transformation. Chromia sealing began at the fine defect in coated microstructure, while larger pores were permeated later. The increase in concentration and treatment frequency of sealing solution resulted in the decrease of porosity of coating layer, while cracks occurred partially after the third treatment. After twice treatment of 10M $CrO_3$ solution, microhardness and breakdown voltage of $Al_2O_3$ coatings were found to increase by ${\fallingdotseq}$ 50% and ${\fallingdotseq}$ 390% respectively than without post-treatment.

Keywords

References

  1. A. H. Seok and C. H. Lee, “A Study on the Wear Behavior of Plasma Sprayed WC-12% Co/NiCrSiB Mixed Coating,” J. Kor. Inst. Met & Meter., 36 [6] 943-51 (1998).
  2. B.-Y. Kim, D. Y. Lee, Y.-N. Kim, M.-S. Jeon, J. K. Song, S. Y. Kim, and K. Y. Kim, “Effect of Al Alloy Composition on Physical and Crystallographical Properties of Plasma Electrolytic Oxidized Coatings. I. Physical Properties of PEO Layer(in Korean),” J. Kor. Ceram. Soc., 47 [3] 256-61 (2010). https://doi.org/10.4191/KCERS.2010.47.3.256
  3. B.-Y. Kim, D. Y. Lee, M. C. Shin, H.-G. Shin, B.-K. Kim, S. Y. Kim, and K. Y. Kim, “Effect of Al Alloy Composition on Physical and Crystallographical Properties of Plasma Electrolytic Oxidized Coatings II. Crystallographic Analysis of PEO Layer(in Korean),” J. Kor. Ceram. Soc., 47 [4] 283-89 (2010). https://doi.org/10.4191/KCERS.2010.47.4.283
  4. L. Pawlowsky, The Science and Engineering of Thermal Spray Coatings; pp. 28-52, John Wiley & Sons, New York, 1995.
  5. S. Sampath, H. Herman, and S. Rangaswamy, pp. 48 in Proc. of 1st National Thermal Spray Conf., Orlando, 1987.
  6. H. L. Filmer, J. Hochstrasser, A. R. Nicoll, and S. Rangaswamy, “Plasma Spray Deposition of Alumina-Based Ceramic Coatings,” Am. Ceram. Soc. Bull., 69 [12] 1955-58 (1990).
  7. T. C. Willis, J. White, R. M. Jordan, and I. R. Hyghes, pp. 21 in 3rd Inter. Conf. on Solidification Processing, Sheffield, U.K., 1987.
  8. R. A. Pike, V. M. Patarini, R. Zatorski, and F. P. Lamm, “Plasma-sprayed Coatings as Adherend Surface Pretreatments,” Inter. J. Adhesion and Adhesives, 12 [4] 227-31 (1992). https://doi.org/10.1016/0143-7496(92)90058-4
  9. J. Carr and J. Jones, pp. 43 in Post Densified $Cr_2O_3$ Coatings for Adiabatic Engine, Kaman Science. Corp. 1990.
  10. B. Kubota, “Decomposition of Higher Oxide of Chromium Under Various Pressures of Oxygen,” J. Am. Ceram. Soc., 44 [5] 239-48 (1961). https://doi.org/10.1111/j.1151-2916.1961.tb15368.x
  11. K. W. Jzwiak, W. lgnaczak, D. Dominiak, and T. P. Maniecki, “Thermal Stability of Bulk and Silica Supported Chromium Trioxide,” Appl. Catal. A, 253 33-45 (2004).
  12. A. Rahman, M. H. Mohamed, M. Ahmed, and A. M. Aitami, “Characterization of Chromia/Alumina Catalysts by X-ray Photoelectron Spectroscopy, Proton Induced X-ray Emission and Thermogravimetric Analysis,” Appl. Catal. A, 121 203-16 (1995). https://doi.org/10.1016/0926-860X(94)00204-5
  13. F. R. Feret, D. Roy, and C. Boulager, “Determination of Alpha and Beta Alumina in Ceramic Alumina by X-ray Diffraction,” Spectrochem. Acta B, 55 1051-61 (2000). https://doi.org/10.1016/S0584-8547(00)00225-1
  14. Y. K. Park, G. S. Choi, and D. H. Lee, “Effects of Spraying Conditions on the Porosity and Hardness of Plasma Sprayed MgO Stabilized Zirconia Thermal Barrier Coatings,” Kor. J. Mater. Res., 2 [2] 85-94 (1992).
  15. J. R. Davis, pp. 45 in Handbook of Thermal Spray Technology, ASM International, Ohio, USA, 2004.
  16. H. Kim, S. Odoul, C. H. Kim, and Y. G. Kwon, “Electrical Insulation Properties of the Plasma Sprayed Ceramic Coatings,” J. Kor. Inst. Met & Meter., 39 [3] 321-27 (2001).
  17. B. H. Kim and D. S. Suhr, “Effect of Particle Size on the Characterization of Plasma Sprayed Al2O3 Coating Layer,” Kor. J. Mater. Res., 9 [4] 428-33 (1999).