title: Laser ultrasonic surface wave inspection of alumina ceramics of varying density
abstract: In this paper, the surface acoustic wave velocity results acquired from the inspection of specially manufactured and characterised alumina ceramic materials are presented. Ultrasonic velocity data of alumina-based ceramics in the range 60-100% theoretical density was generated utilising non-contacting laser-ultrasonic measurements based on laser generation and detection of surface acoustic waves with the objective of creating a routine technique for industrial advanced alumina inspection. With linear fitting the surface acoustic wave velocity data serves as a calibration graph for using laser ultrasonics for routine monitoring of alumina. A second laser ultrasonic technique based on the laser generation and foil transducer detection of surface acoustic waves was used to validate the surface acoustic wave velocities measured by the laser generation/detection technique.
authors.affiliation: National Microelectronics Research Centre, Lee Maltings, Cork, Ireland. lkehoe@nmrc.ucc.ie
authors.initials: L
authors.lastname: Kehoe
authors.initials: G
authors.lastname: Coyle
authors.initials: S
authors.lastname: Murray
authors.initials: CM
authors.lastname: Flannery
authors.initials: GM
authors.lastname: Crean