Abstract
Nondestructive techniques for evaluating and characterizing coatings were extensively demanded by the thermal spray community; nonetheless, few results have been produced in practice due to difficulties in analyzing the complex structure of thermal spray coatings. Of particular interest is knowledge of the elastic modulus values and Poisson’s ratios, which are very important when seeking to understand and/or model the mechanical behavior or to develop life prediction models of thermal spray coatings used in various applications (e.g., wear, fatigue, and high temperatures). In the current study, two techniques, laser-ultrasonics and Knoop indentation, were used to determine the elastic modulus of thermal spray coatings. Laser-ultrasonics is a noncontact and nondestructive evaluation method that uses lasers to generate and detect ultrasound. Ultrasonic velocities in a material are directly related to its elastic modulus value. The Knoop indentation technique, which has been widely used as a method for determining elastic modulus values, was used to compare and validate the measurements of the laser-ultrasonic technique. The determination of elastic modulus values via the Knoop indentation technique is based on the measurement of elastic recovery of the dimensions of the Knoop indentation impression. The approach used in the current study was to focus on evaluating the elastic modulus of very uniform, dense, and near-isotropic titania and WC-Co thermal spray coatings using these two techniques. Four different coatings were evaluated: two titania coatings produced by air plasma spray (APS) and high-velocity oxyfuel (HVOF) and two types of WC-Co coatings, conventional and multimodal (nanostructured and microsized particles), deposited by HVOF.
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References
L. Pawlowski, The Science and Engineering of Thermal Spray Coatings, John Wiley & Sons, Chichester, West Sussex, England, 1995
R. McPherson, A Review of Microstructure and Properties of Plasma Sprayed Ceramic Coatings, Surf. Coat. Technol., Vol 39/40, 1989, p 173–181
R. McPherson and B.V. Shaffer, Interlamellar Contact Within Plasma-Sprayed Coatings, Thin Solid Films, Vol 97, 1982, p 201–204
R. McPherson, The Relationship Between the Mechanism of Formation, Microstructure and Properties of Plasma-Sprayed Coatings, Thin Solid Films, Vol 83, 1981, p 297–310
R. McPherson, A Model for the Thermal Conductivity of Plasma-Sprayed Ceramic Coatings, Thin Solid Films, Vol 112, 1984, p 89–95
J. Ilavsky, A.J. Allen, G.G. Long, and S. Krueger, Influence of Spray Angle on the Pore and Crack Microstructure of Plasma-Sprayed Deposits, J. Am. Ceram. Soc., Vol 80 (No. 3), 1997, p 733–742
S.H. Leigh and C.C. Berndt, Quantitative Evaluation of Void Distributions Within a Plasma-Sprayed Ceramic, J. Am. Ceram. Soc., Vol 82 (No. 1), 1999, p 17–21
T. Nakamura, G. Qian, and C.C. Berndt, Effects of Pores on Mechanical Properties of Plasma-Sprayed Ceramic Coatings, J. Am. Ceram. Soc., Vol 83 (No. 3), 2000, p 578–584
S. Kuroda and T.W. Clyne, The Quenching Stress in Thermally Sprayed Coatings, Thin Solid Films, Vol 200, 1991, p 49–66
S.H. Leigh, C.K. Lin, and C.C. Berndt, Elastic Response of Thermal Spray Deposits Under Indentation Tests, J. Am. Ceram. Soc., Vol 80 (No. 8), 1997, p 2093–2099
R.S. Lima and B.R. Marple, High Weibull Modulus HVOF Titania Coatings, J. Thermal Spray Technol., Vol 12 (No. 2), 2003, p 240–249
R.S. Lima and B.R. Marple, Optimized High Velocity Oxy-Fuel Titania Coatings, J. Thermal Spray Technol., Vol 12 (No. 3), 2003, p 360–369
R.S. Lima and B.R. Marple, Comparative Study of HVOF and APS Titania Coatings, Proceedings from the First International Surface Engineering Congress and the 13th IFHTSE Congress, N. Dahotre, J.O. Iroh, D. Herring, S. Midea, and H. Kopech, Ed., ASM International, 2003, p 515–519
D.B. Marshall, T. Noma, and A.G. Evans, A Simple Method for Determining Elastic-Modulus-to-Hardness Ratio using Knoop Indentation Measurements, J. Am. Ceram. Soc., Vol 65 (No. 10), 1982, p C-175–176
S. Parthasarathi, B.R. Tittmann, K. Sampath, and E.J. Onesto, Ultrasonic Characterization of Elastic Anisotropy in Plasma-Sprayed Alumina Coatings, J. Thermal Spray Technol., Vol 4 (No. 4), 1995, p 367–373
G. Rosa, P. Psyllaki, R. Oltra, T. Montesin, C. Coddet, and S. Costil, Laser Ultrasonic Testing for Estimation of Adhesion of Al2O3 Plasma Sprayed Coatings, Surf. Eng., Vol 17 (No. 4), 2001, p 332–338
X.Q. Ma, Y. Mizutani, and M. Takemoto, Laser-Induced Surface Acoustic Waves for Evaluation of Elastic Stiffness of Plasma Sprayed Materials, J. Mater. Sci., Vol 36, 2001, p 5633–5641
D. Schneider, T. Schwarz, H.P. Buchkremer, and D. Stover, Non-Destructive Characterization of Plasma-Sprayed ZrO2 Coatings, Thin Solid Films, Vol 224, 1993, p 177–183
D. Schneider and B. Schultrich, Elastic Modulus: A Suitable Quantity for Characterization of Thin Films, Surf. Coat. Technol., Vol 98, 1998, p 962–970
M. Viens, D. Drolet, A. Blouin, J. P. Monchalin, C. Moreau, Nondestructive Characterization of Plasma Sprayed Coatings by Laser Ultrasonics, Thermal Spray: Practical Solutions for Engineering Problems, C.C. Berndt, Ed., Oct 7–11, 1996 (Cincinnati, OH), ASM International, 1996, p 947–951
D.N. Boccaccini and A.R. Boccaccini, Dependence of Ultrasonic Velocity on Porosity and Pore Shape in Sintered Materials, J. Nondestruct. Eval., Vol 16 (No. 4), 1997, p 187–192
M. Asmani, C. Kermel, A. Leriche, and M. Ourak, Influence of Porosity on Young’s Modulus and Poisson’s Ratio in Alumina Ceramics, J. Eur. Ceram. Soc., Vol 21, 2001, p 1081–1086
M.E. Browne, Physics for Engineering and Science, McGraw-Hill, 1999
E. Schreiber, O.L. Anderson, and N. Soga, Elastic Constants and Their Measurement, McGraw-Hill, 1973
Y.M. Liu, T.E. Mitchell, and H.N.G. Wadley, Anitropic Damage Evolution in Unidirectional Fiber Reinforced Ceramics, Acta Mater., Vol 45 (No. 10), 1997, p 3981–3992
Q.B. Zhou, S.Y. Zhang, and Y.K. Lu, Acoustic Anisotropy of Piezoelectric PbB4O7 Crystals Studied by Laser Ultrasonics, Mater. Sci. Eng., B, Vol 83, 2001, p 249–253
M.A. Camerucci, G. Urretavizcaya, and A.L. Cavalieri, Mechanical Behavior of Cordierite and Cordierite-Mullite Materials Evaluated by Indentation Techniques, J. Eur. Ceram. Soc., Vol 21, 2001, p 1195–1204
J. Gong, Z. Zhao, Y. Yang, Z. Guan, and H. Miao, Statistical Variability in the Indentation Toughness of TiCN Particle Reinforced Al2O3 Composite, Mater. Lett., Vol. 49, 2001, p 357–360
H.J. Kim and Y.G. Kweon, Elastic Modulus of Plasma-Sprayed Coatings Determined by Indentation and Bend Tests, Thin Solid Films, Vol 342, 1999, p 201–206
J. Li and C. Ding, Determining Microhardness and Elastic Modulus of Plasma-Sprayed Cr3C2-NiCr Coatings Using Knoop Indentation Testing, Surf. Coat. Technol., Vol 135, 2001, p 229–237
D. Zhu and R.A. Miller, Thermal Conductivity and Elastic Modulus Evolution of Thermal Barrier Coatings Under High Heat Flux Conditions, J. Thermal Spray Technol., Vol 9 (No. 2), 2000, p 175–180
S.W.K. Kweh, K.A. Khor, and P. Cheang, Plasma-Sprayed Hydroxyapatite (HA) Coatings with Flame-Spheroidized Feedstock: Micro-structure and Mechanical Properties, Biomaterials, Vol 21, 2000, p 1223–1234
B.R. Marple, J. Voyer, J.F. Bisson, and C. Moreau, Thermal Spraying of Nanostructured Cermet Coatings, J. Mater. Process. Technol., Vol 117, 2001, p 418–423
MatWeb-Material Property Data Home Page, www.matweb.com (accessed Sept 24, 2002)
J.C. Anderson, K.D. Leaver, R.D. Rawlings, and J.M. Alexander, Materials Science, 4th ed., Chapman & Hall, 1991
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The original version of this article was published as part of the ASM Proceedings, Thermal Spray 2003: Advancing the Science and Applying the Technology, International Thermal Spray Conference (Orlando, FL), 5–8 May, 2003, Basil R. Marple and Christian Moreau, Eds., ASM International, 2003.
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Lima, R.S., Kruger, S.E., Lamouche, G. et al. Elastic modulus measurements via laser-ultrasonic and knoop indentation techniques in thermally sprayed coatings. J Therm Spray Tech 14, 52–60 (2005). https://doi.org/10.1361/10599630522701
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DOI: https://doi.org/10.1361/10599630522701