A method of laser ultrasound tomography for solid surfaces mapping

Abstract

Surface control is an important problem for production inspection in industry. Traditionally it is solved using mechanical and optical profilometry, providing high spatial resolution. However, such methods are inappropriate for bodies immersed in opaque liquids and require preliminary preparation of samples. Current work focuses on an application of a method of laser ultrasound tomography to mapping of solid surfaces. The suggested approach combines high acoustical resolution, high performance and allows profilometry of contaminated and immersed samples. An automated prototype for real-time surface profile measurements is constructed and tested on several bodies of revolution. Linear approximation of a cylinder profile obtained by the prototype shows maximum approximation inconsistency of 15 μm. The results are verified by those obtained by the conventional x-ray method.