论文信息 - Laser generated ultrasound at modified metal surfaces

Laser generated ultrasound at modified metal surfaces

Abstract A study has been made of the ultrasonic pulses generated at modified metal surfaces by laser irradiation. Both longitudinal and shear acoustic modes have been investigated, generation at modified and free surfaces being compared. The use of a Q -switched Nd: YAG laser enabled experiments to be carried out at optical power densities above and below the threshold for plasma formation. Qualitative models of the acoustic sources existing in each case are proposed, which explain the experimental effects of surface modification; these include the observed changes in generation efficiency and longitudinal directivity.

[1] C. H. Skeen,et al. Laser‐induced stress‐wave and impulse augmentation , 1972 .

[2] J. Ready. Effects Due to Absorption of Laser Radiation , 1965 .

[3] R. J. von Gutfeld,et al. Thermoelastic generation of elastic waves for non-destructive testing and medical diagnostics , 1980 .

[4] C. A. Calder,et al. Noncontact material testing using laser energy deposition and interferometry , 1978 .

[5] Richard M. White,et al. Excitation of Surface Elastic Waves by Transient Surface Heating , 1968 .

[6] Richard M. White,et al. Generation of Elastic Waves by Transient Surface Heating , 1963 .

[7] J. Fox. Effect of water and paint coatings on laser‐irradiated targets , 1974 .

[8] Robert Lee Melcher,et al. 20‐MHz acoustic waves from pulsed thermoelastic expansions of constrained surfaces , 1977 .

[9] M. P. Felix,et al. Laser-generated ultrasonic beams. , 1974, The Review of scientific instruments.

[10] N. C. Anderholm. LASER‐GENERATED STRESS WAVES , 1970 .

[11] J. C. Moulder,et al. Laser‐induced Rayleigh waves in aluminum , 1979 .

[12] R. G. Jung,et al. Quantitative assessment of laser‐induced stress waves generated at confined surfaces , 1974 .