The Evaluation of Crack Propagation in Functionally Graded Materials with Coatings

코팅 경사기능 재료의 균열전파에 관한 평가

  • Kwon, Oh-Heon (Division of Safety Engineering, Pukyong National University)
  • 권오헌 (부경대학교 안전공학부)
  • Published : 2008.08.31

Abstract

Recently, new functionally graded material(FGM) that has a spatial variation in composition and properties is developed because of its good quality. This material yields the demands for resistance to corrosion and high temperature in turbine blade, wear resistance as in gears and high strength machine parts. Especially coating treatment in FGM surface brings forth a mechanical weak at the interface due to discontinuous stress resulting from a steep material change. It often, leads cracks or spallation in a coating area around an interface. The behavior of propagation cracks in FGMs was here investigated. The interface stresses were reduced because of graded material properties. Also graded material parameter with exponential equation was founded to influence the stress intensity factor. And the resistance curve with FGM coating was slightly increased.

Keywords

References

  1. T. T. Mattew, J. M. Robert, "Crack propagation in graded composite", Composites Science and Tech., Vol. 65, pp. 201-220, 2005 https://doi.org/10.1016/j.compscitech.2004.07.004
  2. K. J. Raob, "$Al_2O_3$ composite coatings for thermal barrier application", Compos, Sci Tech., Vol. 57, No. 1, pp. 81-89, 1997 https://doi.org/10.1016/S0266-3538(96)00111-X
  3. W. Jianxin., M. L. Chad, "On the fracture toughness of ferroelectric ceramic with electric field applied parallel to the crack front", Acta Materialia, Vol. 52, pp. 3435-3446, 2004 https://doi.org/10.1016/j.actamat.2004.03.041
  4. F. Delale, F. Erdogan, "The crack problem for a nonhomogeneous plane", Jour. of App. Mech., Vol. 50, pp. 609-614, 1983 https://doi.org/10.1115/1.3167098
  5. H. P. Xiong, A. Kawasaki, Y. S. Kang, R. Watanabe, "Experimental study on heat insulation performance of functionally graded metal/ceramic coatings and their fracture behavior at high surface temperature", Surface & Coatings Tech.,Vol. 194, pp. 203-214, 2005 https://doi.org/10.1016/j.surfcoat.2004.07.069
  6. P. R. Marur, H. V. Tippur, "Evaluation of mechanical properties of functionally graded material", Jour. of testing and Evaluation, Vol. 26. pp. 539-545, 1998 https://doi.org/10.1520/JTE12112J
  7. C. E. Rousseau, "Evaluation of crack tip field and fracture parameters in functionally graded materials", Ph.D. Dissertation, Auburn University, 2000
  8. H. Cai, G. Bao, "Crack bridging in functionally graded coatings", Int. J. Solids Structure, Vol. 35, No.7-8, pp. 701-717, 1998 https://doi.org/10.1016/S0020-7683(97)00082-6
  9. V. Parameswaran, A. Shukla, "Asymptotic stress field for stationary cracks along the gradient in functionally graded materials", J. Appl. Mech., Vol. 69, pp. 240-243, 2002 https://doi.org/10.1115/1.1459072
  10. S. Chi, Y. L. Chung, "Cracking in coating sub strate composite with multi layered and coatings", Eng. Fract. Mech., Vol. 70, pp. 1227-1243, 2003 https://doi.org/10.1016/S0013-7944(02)00114-5
  11. J. Abanto, J. Lambros, "Investigation of crack growth in functionally graded materials using digital image correlation", Eng. Fract. Mech., Vol. 69, pp. 1695-1711, 2002 https://doi.org/10.1016/S0013-7944(02)00058-9