A PRELIMINARY STUDY OF LASER-INDUCED ACOUSTIC EMISSION

Abstract

Possibly the first published account of acoustic emission (AE) induced by continuous wave laser action is described. A 400 W CO₂ laser was used to ablate the surfaces of fused silica of delay line quality and laminated windscreen glass. The silica plate gave no AE count and remained intact after the conclusion of the laser action. The windscreen glass gave a strong count which started some time after the termination of ablation and the glass shattered with considerable force two minutes later. The strong sensitivity of the AE activity to material type, and/or stress distribution, suggests that the use of laser irradiation may be a useful alternative to the application of quasistatic stresses, i.e. mechanical testing, for AE studies of materials.

KEYWORDS:

• Acoustic emission
• Laser
• Thermal shock