Noncontact characterization of adhesion of surface layers by laser-generated acoustic waves
نویسندگان
چکیده
Laser-induced spallation is proposed as a powerful means for the investigation of adhesion properties of solid surface films. Ultrasonic pulses are produced at the back side of the sample by the impact of Nd:YAG-laser pulses. At the front side, the induced ultrasonic surface displacements are monitored with a 300 MHz bandwidth fiber-optic interferometer, which is proposed as a versatile point-detection ultrasonic transducer. The technique is applied to the timeresolved monitoring of laser-induced spallation and debonding of surface films.
منابع مشابه
Design and Application of a Photoacoustic Sensor for Monitoring the Laser Generated Stress Waves in Optical Fiber
Measurement of stress transients generated by a 400ns pulsed HF laser in an infrared fluoride glass fiber has been made using fast time – response piezoelectric film transducer. Acoustic signals up to 12 mV with frequencies ranging in megahertz generated by 21 mJ laser pulse when passed through the fiber axis in the linear region. It is shown that useful information such as onset of non - linea...
متن کاملDetection of flaws on metal surfaces using tone burst laser ultrasound
Metal surface flaws on can be detected using the frequency transmission characteristics of surface acoustic waves (SAW). In addition, noncontact, remote detection can be made possible by using laser ultrasound. So far, broadband SAW generated by a single generation laser has been used for surface flaw detection[1]. Results have shown that the SAW transmitted across a slit of depth 0.5 mm showed...
متن کاملCharacterization of a Polycrystalline Material with Laser-Excited Nonlinear Surface Acoustic Wave Pulses
2 Department of Physics, Texas A & M University, College Station, Texas 77843-4242, U.S.A. 3 General Physics Institute, Moscow 117942, Russia. 4 To whom correspondence should be addressed. E-mail: [email protected] High-amplitude nonlinear surface acoustic waves (SAWs) generated by laser pulses were observed in polycrystalline material (stainless steel), and the nonlinear acoustic p...
متن کاملCharacterization of Nd: Yag Laser Radiation Effects on Ti6Al4V Physico-Chemical Properties: An In Vivo Study
The effect of a Nd: YAG laser (1064 nm) has been studied on Ti6Al4V alloy in terms of optical and physical parameters for biomedical applications. The superior surface microhardness hardness (i.e. 377 VHN) is attributed to grain refinement associated with laser melting and rapid solidification. The electrochemical property, mainly pitting corrosion resistance, has been carried out in Hanks salt...
متن کاملAcoustic Waves Generated by a Laser Line Source on the Surface of a Cylindrical Rod or Cavity
In this work, a model is proposed to predict acoustic waves generated in a homogeneous and isotropic cylindrical cavity by a laser line source. The Fourier series expansion is introduced for one spatial coordinate to solve this transient response problem. Theoretical displacements are obtained for an aluminum cylindrical cavity of internal diameter 40 mm. The corresponding displacements are obs...
متن کامل