Measurement of internal friction in polycrystalline materials using laser-generated ultrasound

A new technique is presented allowing to measure ultrasonic absorption or internal friction over a wide temperature range in polycrystalline materials by generating reverberation fields using short laser pulses and by observing their decay using optical interferometers for detection. Aluminum base alloys (AlCuPb and AlMg3), white cast iron, monocrystalline copper are discussed.