Laser Treatment as a New Approach to the Passivation of Iron-Based Historical Monuments

Abstract

This article is devoted to the study of the possibility of the passivation of iron-based metallic materials. The experimental results obtained for the laser treatment of carbon steel model samples by the radiation of repetitively pulsed and continuous-wave 1.064 µm Nd:YAG lasers are described. It is shown that the laser treatment allows the formation of dense protection films, 62–77 microns thick, on the steel surface. The films enhance the anticorrosion properties of the metal. Exposure to laser radiation reduces the surface roughness (from Ra = 0.53 µm to Ra = 0.38 µm). Laser radiation power densities of 10.2 × 105 W/cm2 and 10.7 × 105 W/cm2 for these two laser generating modes, respectively, correspond to the optimum (in terms of the degree of corrosion resistance) modes of steel treatment. The conducted studies show that the application of Nd: YAG lasers is a promising method for the surface passivation of artworks created from steel and cast iron. One of the most promising applications of the proposed method for the anticorrosion protection of iron is the passivation of the surface of iron-based historical monuments.

Keywords

• laser passivation
• Nd:YAG laser
• anticorrosion coating
• steel
• cultural heritage
• historical monument