Research On Milling Deformation Of Aluminum Honeycomb Core

Aluminum honeycomb core material is a kind of thin-walled multi-core lattice structure material,which has the characteristics of low density,light weight,high specific strength and high specific stiffness in the axial direction of the core lattice.It is widely used in aerospace,automobile and other fields.High speed milling is the most commonly used method to process aluminum honeycomb core.Because the rigidity of the material perpendicular to the axial direction of the core lattice is very low,it is easy to cause the deformation of the honeycomb core in the process of fixing and processing the honeycomb core.In order to reduce the processing deformation of aluminum honeycomb core,the research on clamping fixture and processing technology was carried out,and the corresponding clamping fixture for aluminum honeycomb core was designed.Through ABAQUS finite element simulation and milling experiment,the influence of cutting parameters,ice holding height and feed mode on the deformation of honeycomb wall in the processing was explored,The results show that these factors have significant influence on the deformation of honeycomb wall,and the processing technology is optimized based on the goal of reducing the deformation of honeycomb wall.(1)The paper designs the corresponding fixture for the problem of the unsound fixation when the wire cutting machine and milling machine are processing aluminum honeycomb core.When using the slow wire cutting machine to process aluminum honeycomb core,the working fluid will produce impact disturbance to the honeycomb core.The corresponding fixture is designed to solve this problem,and the reliability of the fixture is verified by the wire cutting experiment;When processing aluminum honeycomb core on milling machine,the freezing method is used to hold,liquid nitrogen is used as the cold source to design the clamp structure,and the temperature distribution of the honeycomb core is simulated and analyzed by ABAQUS finite element method,and the influence law of ice fixing height on the temperature distribution of honeycomb core is obtained;The theoretical holding force and the holding efficiency are calculated.It is proved that the process of the holding is fast and reliable when the clamp is used to hold the aluminum honeycomb core.(2)The influence of cutting amount and ice holding height on the deformation of honeycomb wall is studied.The results show that when the feed speed increases or the spindle speed decreases,the deformation of honeycomb wall will increase,while when the milling depth and ice holding height change,the deformation of honeycomb wall is not monotonous.The deformation of honeycomb wall is related to cutting force and the rigidity of honeycomb wall.When the cutting force increases,it will easily lead to the increase of deformation.When the rigidity of honeycomb wall increases,the honeycomb wall will not easily deform,but the excessive rigidity will lead to the extrusion and friction strength of the machined surface of honeycomb wall,and the deformation of honeycomb wall will be increased.(3)The influence of the contact position of the cutter and the honeycomb wall,the feed direction of the tool and the entrance angle of the honeycomb wall is different,which has a great influence on the deformation of the honeycomb wall.The results show that for the individual honeycomb wall,the deformation of the honeycomb wall is often larger in the middle area far from the node,on the other hand,the more the circular velocity direction of the tool is closer to the vertical state with the honeycomb wall,The larger the deformation of the honeycomb wall will be.The reason of the above rules is also related to cutting force and honeycomb wall rigidity.The rigidity of honeycomb wall is weak except for nodes,and deformation is easy to occur.The entrance angle of cut will affect the force perpendicular to the honeycomb wall.The closer the entrance angle of entry is to 90 °,The greater the force in this direction,the greater the deformation.According to the above analysis,the feeding method is optimized to reduce the deformation of double honeycomb wall.