Study On Laser Technology For Removal Of Surface Contaminants From Pottery Cultural Relics

The cleaning of pottery relics is the first step to protect them.Compared with the traditional contact cleaning method,it may cause damage to the matrix of ceramic relics or damage to painted pigments,Laser cleaning using non-contact is of great significance means for the expansion and extension of cleaning technology.The experimental cleaning parameters and threshold EOS-QS type 1064nm laser cleaning machine are used to explore the surface pollutants of painted surface soil and clay relics,and used in the cleaning of pottery relics.The main research contents are as follows:(1)Damage threshold of ceramic surface pigments:According to 4 kinds of pigments which are common on painted pottery surface,four kinds of pigments,such as mineral green,azurite,clam powder,iron red,damage energy of iron red,clam powder,azurite and mineral green is 700 m J?800m J?500m J?550m J,and the damage threshold is 5.57 J/cm~2?6.37J/cm~2?3.98 J/cm~2?4.38 J/cm~2,For safety cleaning,the energy should be strictly controlled below the upper limit energy of 650 m J?750m J?450m J?500m J when laser cleaning is carried out on the surface of the four pigments.(2)Effect of the concentration of reinforcement on the cleaning effect of the soil on the pigment surface:microscopic observation and the calculation of the cleaning rate show that the soil on the cleaning pigment surface is more suitable for FR mode,and the B72 and SF-016,of 1%,3%and 5%concentrations are prepared to explore the concentration of reinforcement suitable for laser cleaning.The results show that the cleaning energy of the soil on the surface of the four pigments will increase with the increase of the concentration of the reinforcement,but all of them are below the damage energy of the pigment and will not cause damage to the pigment.However,when the concentration of reinforcement is 5%,the cleaning energy of the soil on the surface of the two pigments is greater than that of the pigment,and the pigment itself is damaged.Therefore,laser cleaning of the surface of the pigment soil is not suitable for 5%concentration of reinforcement.(3)Research on the threshold of laser cleaning of clay objects on the surface of pottery relics:the simulation experiment selects the pottery relics to carry on the experiment,finally uses the laser cleaning machine to carry on the cleaning experiment to the actual archaeological unearthed pottery relics and evaluates the cleaning effect.The cleaning rate was characterized by area ratio and cleaning depth before and after cleaning and observed by scanning electron microscope.The cleaning threshold was 1.98 J/cm~2,and the cleaning rate was more than 90%.In this paper,the technology of laser removal of surface pollutants from ceramic relics is studied,The safety of cleaning process is improved.This study enriches the cleaning methods of surface pollutants of ceramic relics,For the further protection of pottery cultural relics to provide protection.