Abstract
Inline inspection of additive manufactured components for subsurface defects using laser ultrasonics (LU) is still technically challenging due to various complicating factors including material microstructure, anisotropy, and surface topography. A new method for determining surface topography during LU inspection is presented that does not require any additional equipment or measurements. The ultrasonic generation laser beam is positioned at an oblique angle to the test surface, while the detection laser beam is normal to the surface. This geometry causes the path length of the ultrasonic head (skimming) and Rayleigh waves, which follow along the surface, to vary with surface profile. Therefore, the variation in wave arrival time can be used to infer the surface profile. The inferred profile can then be compensated for during inline LU data processing to yield greater accuracy in imaging subsurface defects. The method is demonstrated using numerically modelled data as well as experimental measurements.
How to Cite:
Volker, A. ., Klein, M. ., Bobbs, B. ., Wiedmann, M. . & Honarvar, M. ., (2019) “Improved laser ultrasonic inspection for additive manufacturing by incorporating surface profiling”, Review of Progress in Quantitative Nondestructive Evaluation .
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