Method for monitoring and controlling laser shock peening using temporal

Abstract

A method for quality assurance of a laser shock peening process of workpieces includes measuring and recording or temporal light intensity data over a short period during the duration of a plasma associated with the vaporized material from laser shots fired during a production laser shock peening process. The recorded temporal data is then analyzed to obtain an instantaneous optical spectrum of the plasma and then used to provide statistical control of the production laser shock peening process. One correlation function of the present invention is based on a time integrated spectral peak intensity wavelength curve for each of the laser firings and for which a peak intensity wavelength is determined for a plurality of times during each plasma of a plurality or all of the firings. Production results from the analysis of the instantaneous optical spectrum is used to determine whether the production laser shock peening process is acceptable. One embodiment of the method compares the production results from the analysis of the instantaneous optical spectrum to a correlation of test results from the analysis of instantaneous optical spectrum and high cycle fatigue failure based on high cycle fatigue tests of test workpieces that are the same or related to the production workpieces and that were laser shock peened in the same or similar laser shock peening apparatus.