Study On The Controllability And Efficiency Of Infrared Laser Paint Removal Of Aircraft Aluminum Alloy Skin

Laser cleaning technology is a new type of paint removal technology,which can effectively remove the paint layer.Compared with the traditional paint removal technology,it has the advantages of environment-friendly,high efficiency with low consumption and controllable of paint removal effect.The controllability of laser paint removal means that the effect of paint removal can be controlled through the selection of laser energy density.At present,most of the researches on laser paint removal are based on the effect of paint removal without damage to the substrate.However,the effect of paint removal required by aircraft is not the same for different maintenance purposes.For example,only the top coat layer needs to be removed when the aircraft is changed from the passenger to the cargo or returned for rent inspection;and the thickness of the residual paint layer needs to be controlled when the local touch up paint,surface renovation,etc.Based on this,this paper mainly focuses on the delamination controlled laser paint removal and thickness controlled laser paint removal.In the study of laser delamination and controlled paint removal,the paper determines the primary parameters through theoretical analysis and calculation,and gradually optimizes the laser energy density through the combination of test results feedback,finally obtains the best laser energy density under the research conditions,which provides a reference for the practical application of the project.In the study of thickness controlled laser paint removal,the parameter range from the damage of paint surface to the complete paint removal is determined.In order to better explore the law of energy density and paint removal thickness,the paper selects five energy density values evenly distributed in the interval for test,and introduces the test results to curve fitting,to get the laser process parameters,and finally experimental verification,to get the law of excitation energy density and paint removal thickness.At the same time,the efficiency of laser paint removal is also the focus of aviation maintenance units.In this paper,the relationship between defocusing amount,spot area,incident angle and paint removal efficiency is studied by the way of test and test,and the relationship between parameters and paint removal efficiency curve is analyzed,and the relationship between parameters and paint removal efficiency is obtained.At the end of the paper,the ablation effect and vibration effect in the process of laser paint removal are verified,and the mechanism of laser paint removal is described.The results show that the delamination controlled laser paint removal can be realized when the laser energy density is 25.4 J/cm~2,that is,the top coat is completely removed while the primer is almost undamaged.The relationship between the laser energy density and the residual thickness of the paint layer accords with the first-order attenuation index function.When the laser energy density is small,the residual thickness of the paint layer is large.With the increase of the energy density,the residual thickness of the paint layer decreases rapidly.The paper summarizes the law and fits the relationship between the laser energy density and the residual thickness of the paint layer,which provides a reference for the industrial application.In the study of laser paint removal efficiency,the results show that the way to change the laser spot area is the most direct and has the greatest impact on paint removal efficiency.Under the experimental conditions,the laser paint removal efficiency increases by a maximum of 17.2 times;secondly,adjusting the incident angle to change the laser paint removal efficiency can increase the paint removal efficiency by a maximum of1.8 times;finally,the way to defocus affects the paint removal efficiency,the maximum can be achieved The paint removal efficiency is increased by 1.0 times.The research results of laser paint removal controllability can provide technical basis and parameter suggestions for layer controlled paint removal and thickness controlled paint removal on civil aircraft.The energy density paint removal thickness model established can provide theoretical support for similar laser treatment process.The research results of laser paint removal efficiency can provide reference and direction for the next step of efficiency research,and have practical engineering application value.