Study On Laser Cleaning Of Alumina Pollutant On Quartz Glass Surface

Quartz glass is widely used in the fields of semiconductor,light source,laser lens,medical equipment and national defense industry.When polishing quartz glass,the surface of the quartz glass will adsorb particulate pollutants.Traditional cleaning methods can not effectively remove pollutants even cause damage to the quartz glass.Laser cleaning is a method of efficient,pollution-free,non damage and no mechanical contact.It has great potential in cleaning alumina particles on the quartz glass surface.Taking the alumina particles which adsorbed on the quartz glass surface as the research objects.Studied by finite element method,discrete element method and experimental analysis to research the changing rule of laser cleaning alumina particle adsorbed on quartz glass surface.The main contents of the study are as follows:(1)Use the finite element software to establish the temperature field model of alumina.The changing curves between laser pulse number,energy density,pulse width and surface temperature of alumina particles and the internal temperature are obtained.A cleaning force model is established,and the relationship between laser pulse number,energy density,pulse width and cleaning force is obtained.Combined with the adsorption force between the quartz glass and alumina particles,the threshold of alumina removal is predicted.(2)The discrete element model of laser cleaning the quartz glass is established by using the discrete element software PFC.The cleaning threshold is verified and the discrete element model is improved,and the removal process of alumina particles on the surface of the quartz glass is simulated.By analyzing the number of alumina particles on the quartz glass surface before and after cleaning simulation,the changing rule of cleaning rate under different laser pulse number,pulse width and energy density was obtained.The results show that the cleaning rate increases with the increase of pulse number,and decreases with the increase of pulse width,and increases with the increase of the energy density.The cleaning parameters are optimized.(3)The laser cleaning experiment has been carried out.The results show that the laser cleaning of the quartz glass can effectively remove the alumina particles on the surface ofthe quartz glass.The comparison between the experimental results and the discrete element results show that the two trends are consistent.