The analysis of damage threshold in Ruby laser interaction with copper and aluminium

Abstract

Nondestructive methods are dominant in diagnosing the status and protection of all kinds of contemporary industrial objects, as well as objects of industrial heritage. Laser methods open wide possibilities of research in the field of diagnosis and metal processing. This paper presents the results of laser radiation interaction (wavelength λ = 694.3 nm, Ruby laser, Q-switch mode) with metal samples covered with a deposit. The goal of the examination was to determine the maximum energy density of the ruby laser beam, that can be used in diagnostics purposes (interferometric methods; 3D scanning) and as a tool for safe removal of deposits, without interacting with the basic material. Microscopic examination performed with SEM coupled with EDX allowed the determination of the safe laser light energy density levels, which caused the removal of the deposite from the surface of the sample, without degradation of the surface. The energy density up to 20 kJ/m2 is the maximum allowed for diagnosis or deposit removal.