Article Article
Comparison of Pulsed and Lock-In Thermography Techniques for Debond Detection in Ni-B Coatings

Nickel boron (Ni-B) is one of the most widely used coatings in the aerospace, nuclear, and chemical industries due its good corrosion and wear resistance and excellent hardness properties. An essential requisite for a good coating is minimum thickness variation and good adhesion with the substrate. Often, poor bonding quality and the presence of an unbonded region can be a cause for failure in service. In this work, pulsed and lock-in thermography techniques are tested for the evaluation of bond quality of nickel-boron coatings on AISI-grade 316L stainless steel. The results, validated with ultrasonic testing for debond detection in coating systems, showed that both thermography techniques could detect the coating debonds with differences in sizing accuracy. The theoretical aspects for different techniques, their application for debond detection, and the sizing accuracy comparison between them is discussed.


Agarwala, R.C., and Vijaya Agarwala, 2003, “Electroless Alloy/Composite Coatings: A Review,” Sadhana, Vol. 28, No. 3–4, pp. 475–493.

Aithal, S., G. Rousset, L. Bertrand, P. Cielo, and S. Dallaire, 1984, “Photoacoustic Characterization of Subsurface Defects in Plasma Sprayed Coatings,” Thin Solid Films, Vol. 119, No. 2, pp. 153–158.

Almond, D.P., P.M. Patel, I.M. Pickup, and H. Reiter, 1985, “An Evaluation of Suitability of Thermal Wave Interferometry for the Testing of Plasma Sprayed Coatings,” NDT International, Vol. 18, No. 1, pp. 17–24.

Balageas, D.L., J.C. Krapez, and P. Cielo, 1986, “Pulsed Photothermal Modeling of Layered Materials,” Journal of Applied Physics, Vol. 59, No. 2, doi: 10.1063/1.336690.

Bastianini, F., A. Di Tommaso, and G. Pascale, 2001, “Ultrasonic Non-Destructive Assessment of Bonding Defects in Composite Structural Strengthenings,” Composite Structures, Vol. 53, No. 4, pp. 463–467.

Busse, G., D. Wu, and W. Karpen, 1992, “Thermal Wave Imaging with Phase Sensitive Modulated Thermography,” Journal of Applied Physics, Vol. 71, No. 8, doi: 10.1063/1.351366.

Cielo, P., 1984, “Pulsed Photothermal Evaluation of Layered Materials,” Journal of Applied Physics, Vol. 56, No. 1, pp. 230–234.

Delanthabettu, Sharath, Murugesan Menaka, Balasubramanian Venkatraman, and Baldev Raj, 2015, “Defect Depth Quantification Using Lock-In Thermography,” Quantitative InfraRed Thermography Journal, Vol. 12, No. 1, doi: 10.1080/17686733.2015.1013663.

Delaunois, F., J.P. Petitjean, P. Lienard, and M. Jacob-Duliere, 2000, “Autocatalytic Electroless Nickel-Boron Plating on Light Alloys,” Surface and Coatings Technology, Vol. 124, Nos. 2–3, pp. 201–209.

Eldridge, Jeffrey I., Charles M. Spuckler, and Richard E. Martin, 2006, “Monitoring Delamination Progression in Thermal Barrier Coatings by Mid-Infrared Reflectance Imaging,” International Journal of Applied Ceramic Technology, Vol. 3, No. 2, pp. 94–104.

Electrochemical Society, 1974, Modern Electroplating, third edition, ed. Frederick Adolph Lowenheim, Wiley, New York, NY.

Foley, E.L., and R.B. Sawyer, 1964, “Thermal Diffusivity of Nickel from 25° to 500° C,” Journal of Applied Physics, Vol. 35, No. 10, doi: 10.1063/1.1713163.

Gordon, G.A., S. Canumalla, and B.R. Tittmann, 1993, “Ultrasonic C-Scan Imaging for Material Characterization,” Ultrasonics, Vol. 31, No. 5, pp. 373–380.

Hasiotis, Theodoros, Efstratios Badogiannis, and Nicolaos Georgios Tsouvalis, 2011, “Application of Ultrasonic C-Scan Techniques for Tracing Defects in Laminated Composite Materials,” Strojniški vestnik – Journal of Mechanical Engineering, Vol. 57, No. 3, pp. 192–203.

Kamachi Mudali, U., A. Ravishankar, S. Ningshen, Girija Suresh, Ravikumar Sole, and K. Thyagarajan, 2011, “Materials Development and Corrosion Issues in the Back End of Fuel Cycle,” Energy Procedia, Vol. 7, pp. 468–473.

Kundu, T., A. Maji, T. Ghosh, and K. Maslov, 1998, “Detection of Kissing Bonds by Lamb Waves,” Ultrasonics, Vol. 35, No. 8, pp. 573–580.

Lau, S.K., D.P. Almond, and J.M. Milne, 1991a, “A Quantitative Analysis of Pulsed Video Thermography,” NDT & E International, Vol. 24, No. 4, pp. 195–202.

Lau, S.K., D.P. Almond, and P.M. Patel, 1991b, “Transient Thermal Wave Techniques for the Evaluation of Surface Coatings,” Journal of Physics D: Applied Physics, Vol. 24, No. 3, doi: 10.1088/00223727/24/3/029.

Lloyd, P.A., 1989, “Ultrasonic System for Imaging Delaminations in Composite Materials,” Ultrasonics, Vol. 27, No. 1, pp. 8–18.

Marinetti, P., D. Robba, F. Cernuschi, P.G. Bison, and E. Grinzato, 2007, “Thermographic Inspection of TBC Coated Gas Turbine Blades: Discrimination Between Coating Over-Thickness and Adhesion Defects,” Infrared Physics & Technology, Vol. 49, No. 3, pp. 281–285.

NASA, n.d., “Ultrasonic Testing of Aerospace Materials,” Practice No. PT-TE-1422, NASA 1-6 National Aeronautics and Space Administration, Washington, DC.

Newaz, Golam, and Xiaoqun Chen, 2005, “Progressive Damage Assessment in Thermal Barrier Coatings Using Thermal Wave Imaging Technique,” Surface and Coatings Technology, Vol. 190, No. 1, pp. 7–14.

Oraon, B., G. Majumdar, and B. Ghosh, 2008, “Improving Hardness of Electroless Ni-B Coatings Using Optimized Deposition Conditions and Annealing,” Materials & Design, Vol. 29, No. 7, pp. 1412–1418.

Patel, P.M., and D.P. Almond, 1985, “Thermal Wave Testing of Plasma Sprayed Coatings and a Comparison of the Effects of Coating Microstructure on the Propagation of Thermal and Ultrasonic Waves,” Journal of Materials Science, Vol. 20, No. 3, pp. 955–966.

Riedel, Wolfgang, 1991, Electroless Nickel Plating, Finishing Publications (Stevenage, England) and ASM International (Materials Park, OH).

Riddle, Y.W., and T. O. Bailer, 2005, “Friction and Wear Reduction via an Ni-B Electroless Bath Coating for Metal Alloys,” JOM, Vol. 57, No. 4, pp. 40–45.

Sakagami, Takahide, and Shiro Kubo, 2002, “Development of a New Non-Destructive Testing Technique for Quantitative Evaluations of Delamination Defects in Concrete Structures based on Phase Delay Measurement Using Lock-In Thermography,” Infrared Physics & Technology, Vol. 43, Nos. 3–5, pp. 311–316.

Sankara Narayanan, T.S.N., K. Krishnaveni, and S.K. Seshadri, 2003, “Electroless Ni-P/Ni-B Duplex Coatings: Preparation and Evaluation of Microhardness, Wear and Corrosion Resistance,” Materials Chemistry and Physics, Vol. 82, No. 3, pp. 771–779.

Santangelo, Paolo E., Giulio Allesina, Giovanni Bolelli, Luca Lusvarghi, Ville Matikainen, and Petri Vuoristo, 2017, “Infrared Thermography as a Non-destructive Testing Solution for Thermal Spray Metal Coatings,” Journal of Thermal Spray Technology, Vol. 26, No. 8, pp. 1982–1993.

Shepard, Steven M., James R. Lhota, Bruce A. Rubadeux, David Wang, and Tasdiq Ahmed, 2003, “Reconstruction and Enhancement of Active Thermographic Image Sequences,” Optical Engineering, Vol. 42, No. 5, pp. 1337–1343.

Sun, J.G., 2006, “Analysis of Pulsed Thermography Methods for Defect Depth Prediction,” Journal of Heat Transfer, Vol. 128, No. 4, pp. 329–338.

Tang, Qingju, Junyan Liu, Jingmin Dai, and Zongyan Yu, 2017, “Theoretical and Experimental Study on Thermal Barrier Coating (TBC) Uneven Thickness Detection Using Pulsed Infrared Thermography Technology,” Applied Thermal Engineering, Vol. 114, pp. 770–775.

Venkatraman, B., M. Menaka, R. Subbaratnam, and Baldev Raj, 2008, “Characterization of Colmonoy Coatings Using Lock In Thermography,” 17th World Conference on Non Destructive Testing, 25–28 October 2008, Shanghai, China, accessed at on 15 October 2019.

Zhu, W., Z. Liu, D. Jiao, and H. Xie, 2018, “Eddy Current Thermography with Adaptive Carrier Algorithm for Non-destructive Testing of Debonding Defects in Thermal Barrier Coatings,” Journal of Nondestructive Evaluation, Vol. 37, No. 31, doi: 10.1007/s10921-018-0483-3.

Usage Shares
Total Views
184 Page Views
Total Shares
0 Tweets
0 PDF Downloads
0 Facebook Shares
Total Usage