Non-contact measurement of elastic modulus by using laser ultrasound

Article

Abstract

Non-contact measurement of elastic modulus is necessary for the in-line assessment of material in harsh environments such as high temperature. In this paper, a fully non-contact method to measure elastic modulus is proposed based on the laser ultrasonic technique (LUT) that uses a short-pulsed laser to generate ultrasound and the other laser coupled to an interferometer using a photorefractive crystal to detect the ultrasonic wave displacement. Basically, this method measures velocities of shear wave and longitudinal wave to obtain the elastic modulus. The uniqueness is that the velocity of shear wave is measured in the thermo-elastic regime first and then the velocity of longitudinal wave is measured in the ablation regime. This is because the strong mode of generated ultrasound is the shear wave in the thermo-elastic regime while the longitudinal wave in the ablation regime. Regime change can be achieved simply by switching the laser power, with no change in the measurement setup. In order to demonstrate the usefulness of the proposed method, the elastic modulus of aluminum casting alloy has been measured and the results were compared with a conventional contact method and a destructive tensile test. They showed good agreement with each other, which verified the usefulness of the proposed noncontact elastic modulus measurement method.

Keywords

Elastic modulus Laser ultrasound Non-contact Non-destructive 

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References

  1. 1.
    Li, P., Hao, J., Zhao, J., and Duan, H., “The influence of Ageing Treatment on the Microstructure and the Elastic Modulus of Ti27Nb8Zr Alloy,” Materials Science and Engineering: A, Vol. 527, No. 29, pp. 7469–7474, 2010.CrossRefGoogle Scholar
  2. 2.
    Olympus, “Ultrasonic Transducers,” http://www.olympus-ims.com/ko/ultrasonic-transducers/ (Accessed 23 MAR 2015)Google Scholar
  3. 3.
    Scruby, C. B. and Drain, L. E., “Laser Ultrasonics Techniques and Applications,” CRC Press, pp. 223–324, 1990.Google Scholar
  4. 4.
    Davies, S. J., Edwards, C., Taylor, G., S. and Palmer, S. B., “Laser- Generated Ultrasound: Its Properties, Mechanisms and Multifarious Applications,” Journal of Physics D: Applied Physics, Vol. 26, No. 3, pp. 329–348, 1993.CrossRefGoogle Scholar
  5. 5.
    Lee, H., Chung, C., Kim, C. S., and Jhang, K. Y., “Fully Non- Contact Assessment of Acoustic Nonlinearity according to Plastic Deformation in Al6061 Alloy,” Journal of the Korean Society for Nondestructive Testing, Vol. 32, No. 4, pp. 388–392, 2012.CrossRefGoogle Scholar
  6. 6.
    Aussel, J. D. and Monchalin, J. P., “Precision Laser-Ultrasonic Velocity Measurement and Elastic Constant Determination,” Ultrasonics, Vol. 27, No. 3, pp. 165–177, 1989.CrossRefGoogle Scholar
  7. 7.
    Li, Z. Q., Zhang, X. R., Zhang, S. Y., and Shen, Z. H., “Determination of the Elastic Constants of Metal-Matrix Composites by a Laser Ultrasound Technique,” Composites Science and Technology, Vol. 61, No. 10, pp. 1457–1463, 2001.CrossRefGoogle Scholar
  8. 8.
    Sun, G., Zhou, Z., Chen, X., and Wang, J., “Ultrasonic Characterization of Delamination in Aeronautical Composites using Noncontact Laser Generation and Detection,” Applied Optics, Vol. 52, No. 26, pp. 6481–6486, 2013.CrossRefGoogle Scholar
  9. 9.
    Monchalin, J. P. and Aussel, J. D., “Ultrasonic Velocity and Attenuation Determination by Laser-Ultrasonics,” Journal of Nondestructive Evaluation, Vol. 9, No. 4, pp. 211–221, 1990.CrossRefGoogle Scholar
  10. 10.
    Wild, G. and Hinckley, S., “Acousto-Ultrasonic Optical Fiber Sensors: Overview and State-of-the-Art,” Sensors, Vol. 8, No. 7, pp. 1184–1193, 2008.CrossRefGoogle Scholar
  11. 11.
    Monchalin, J., “Non Contact Generation and Detection of Ultrasound with Lasers,” Proc. of the 16th World Conference on Nondestructive Testing, 2004.Google Scholar

Copyright information

© Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Department of Mechanical convergence EngineeringHanyang UniversitySeoulSouth Korea
  2. 2.School of Mechanical EngineeringHanyang UniversitySeoulSouth Korea

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