Experimental Study On The Cleaning Cultural Relics Of Bronze Using The Laser

As a new type of cleaning technology, laser cleaning technology has made a rapiddevelopment in recent decade. Because it has many advantages, such as small damage to thebasal, non-contact, wide range to clean the basement and less pollution to the environment,etc., it shows a broad application in many fields. Thus, it gradually becomes the importantsupplement and extension of traditional cleaning technology. In the protection and restorationof precious cultural relic, compared with traditional technology, laser cleaning technology hasgreat advantages on the basis of the protection of cultural relics and efficiently removing thedirt covered on the surface of the cultural relics.This paper based on the laser cleaning technology to study the cleaning of our country’sbronze. Laser cleaning technology uses thermal effect of the laser and material surface,impact effect and physical chemical effect to achieve the purpose of cleaning the dirt on thesurface. This paper analyzes the process of bronze corrosion and composition and structure ofrust layer, and it chooses to adopt dry laser cleaning technology to clean the copper corrosionlayer. Through the analysis of the thermal effect and impact of laser and copper surface, thisexperiment simulates the temperature field in the process of change of the laser and coppersurface with Comsol software, test the changes of strength and composition of plasma byLIBS in laser cleaning process, and it cleans the surface of copper by respectively using CO2laser and fiber laser. The cleaning results show that CO2laser is not suitable for this kind ofbronze cleaning. Because its energy and density is low, cleaning off the rust layer is difficult,the pulse time is long, and the basal thermal effect is very big. Compared with different powerof cleaning, the cleaning effect of fiber laser is good. This experiment shows that not only thecleaning efficiency and the result, but also the damage degree of basement, the power of2w is the best.This paper takes the power of2w in fiber laser scanning as example, it puts forward fourkinds of methods to evaluate the cleaning effect: the macroscopic observation, microscopicanalysis, scanning electron microscopy and energy spectrum analysis and laser Ramanspectroscopy. Four ways to obtain a comprehensive evaluation guidelines, macro-contrastimages of cleaning area from the microscope can be seen the exposed brass base, the cleaningrate of binary image processing is more than90%; microscopic comparison of Spectroscopypercentage of cleaning the scanning by electron microscope, oxygen element ratio decreasedto10%after cleaning, and the curve of various types oxide Raman peaks disappear aftercleaning. It is clean if all of above is completed.