Method of destruction-free testing of surfaces using the reflected light pattern

摘要

The surface condition of a workpiece is monitored by polishing the surface (2) and then etching until the coherent light from a laser beam (7) produces the correct pattern on a projection picture (5). The coherent beam is projected at the surface at an angle of 10 - 30 deg . Etching is carried out until the amount of coherent light in the picture is minimised or completely removed (11). Pictures of the surface can then be taken.