| 摘要 |
PURPOSE:To make it possible to obtain the metal fatigue information in a metal sample even in both states before and after fatigue destruction, by locally heating the metal sample by irradiating the same with laser beam and detecting generated acoustic emission (AE). CONSTITUTION:The laser beam generated from a laser oscillator 2 is allowed to irradiate a metal specimen 10 and two-dimensional scanning is applied onto the metal sample 10 by an X-Y displacement mirror mechanism 6. This scanning of laser beam is made synchronous to the raster scanning of a display device 20. The metal sample 10 is locally heated by the irradiation of laser beam and AE is generated by the local heating and detected by an AE pickup 16. Because the detection signal corresponding to the detected AE is outputted from the AE pickup 16, the intensity of average frequency of said detection signal is applied to the display device 20 as a brightness modulation signal. By this method, the image two-dimensionally displaying the fatigue state in the metal specimen 10 is displayed on the display device 20.
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