Study On Laser Forming Mechanism And Forming Rules Of 6061 Aluminum Alloy Thin Plate

With the rapid development of social economy and the vigorous promotion of energy conservation and environmental protection,aluminum alloy materials have been widely used in the process of high-energy and lightweight components in various industries.Because of its small density,higher than strength,higher than rigidity,thermal conductivity,good forming,etc.,it has a great development in aerospace.6061 aluminum alloy compared with other airlines use aluminum alloy material,the forming limit is low,strong corrosion resistance,high strength,high temperature resistant performance is good,so to be used as aerospace plane wing skin material and the material in the fuel oil system,but with the widely use of aluminum alloy,increasingly complicated shape,combined with the components the processing technology of aluminum alloy structure is put forward higher requirements.The traditional forming technology usually makes the corresponding mold according to the shape of the sheet,and the whole process takes a lot of time,capital and labor cost.The laser forming technology can meet the market competition of the rapid updating of manufacturing products due to its noncontact,non-mold and flexible processing.At the same time,due to the controllability of the laser light source,the precise control of the bending process can be achieved by optimizing the process parameters and precisely controlling the size and position of the laser heating area.During laser forming process in order to study the deformation law of aluminum alloy sheet,it is necessary to aluminum alloy material deformation under the action of the laser principle,analyze and predict the deformation of aluminum alloy under the effect of laser forming effect research provides theoretical and experimental basis.The main research work of the dissertation is as follows:(1)The material database of 6061 aluminum alloy laser heat forming process was established.Based on the 6061 aluminum alloy sheet manufacturers provide the performance parameters of 6061 aluminum alloy material,combined with the thermal property parameters of 6061 materials in the references and relevant parameters of the materials used in the experiment,established can be applied to the material database of simulation calculation of SYSWELD,and through the comparison between results of simulation and experiment,shows that building materials database availability.(2)Analysis of the deformation mechanism of 6061 aluminum alloy sheet and the research on bending direction of plate.Detection by SYSWELD simulation and experiment process,the temperature changes in the process of laser forming is analyzed and the change of the free end deformation,the study found that aluminum alloy sheet are produced in the process of laser forming first reverse bending,then generates positive,the deformation of the deformation of the final result is positive.The change of temperature is a sudden and sudden drop,and the maximum temperature increases with the process of laser loading.(3)Effects of different technological parameters on the deformation effect of laser forming.By different laser power,spot diameter,scanning speed under the condition of orthogonal experiments,and get the result of deformation under different process parameters,in the three factors,laser power,the most profound effect on the deformation of the free end times by the influence of scanning speed,impact on the final deformation minimum spot diameter.The final deformation result increases with the increase of laser power and decreases with the increase of scanning speed and spot diameter.(4)Microhardness and microstructure of 6061 aluminum alloy thin plate before and after laser forming.With the increase of the spot scanning speed during the laser forming process,the microhardness of the material in the processed area increases,and the microhardness of the material near the center of the spot is the smallest,and the hardness increases from the center of the spot to the direction of the base material.Compared with the original structure,the processed area structure has fewer defects such as voids and the structure becomes denser,but the cracks in the area also begin to increase,resulting in a decrease in the microhardness of the area.At the same time,there is a clear dividing line between the laser processing area and the substrate structure,and a large number of microcracks are observed at the boundary line position,and the crack propagates along the laser action area.At the same time,the material of the coating layer dissolves into the processed area,resulting in an uneven distribution of the carbon content in the processed area.