Study On The Morphology Of Aluminum Honeycomb By Ultrasonic Cutting With Disc Cutter

Aluminum honeycomb is a thin-walled porous material with many advantages such as high specific strength and stiffness,impact resistance,noise reduction,heat insulation and so on.Aluminum honeycomb has strong stiffness along the hole direction.By bonding and solidifying with composite material or metal plate,it can be made into aluminum honeycomb sandwich structure,which can be used in aerospace,transportation and other fields.It can not only ensure the structural strength of products,but also achieve the purpose of lightweight.However,due to the weak in-plane stiffness of aluminium honeycomb,the honeycomb wall is prone to burr,tear and other processing defects in the process of processing,so the processing technology of aluminium honeycomb is put forward higher requirements.As a new special processing method,ultrasonic cutting with disc cutter has a series of advantages,such as reducing cutting force,improving processing efficiency and improving processing quality.It has been applied to the processing of Nomex honeycomb and other compound materials.However,the research on ultrasonic cutting of aluminum honeycomb with circular blade has rarely been reported.The role of ultrasonic vibration of disc cutter in cutting metal honeycomb,represented by aluminum honeycomb,is not clear yet,and the cutting effect of aluminum honeycomb needs to be further studied.Processing methods and effects of cutting aluminum honeycomb with circular blade with additional axial ultrasonic vibration are studied in this paper from the point of view of processing morphology.The main contents are as follows:By analyzing the cutting speed of the disc cutter after additional ultrasonic vibration,it is found that the vibration speed is much faster than the tangential velocity of the blade,so the main motion in the cutting process is not the tool rotation but the ultrasonic vibration.The ultrasonic vibration of the disc cutter impacts the honeycomb wall and causes micro-plastic deformation on the machined surface.In order to quantitatively study the impact,the plastic deformation of honeycomb wall is used to characterize the impact strength.The geometrical shape of the plastic deformation zone on the machined surface of honeycomb wall was simulated and analyzed by Abaqus software.Based on the energy transformation theory in the process of ultrasonic shot peening,the plastic deformation model of honeycomb wall was established,and the relationship between the ultrasonic processing parameters and the plastic deformation was obtained.The conclusion of the model is verified by single factor test of ultrasonic processing parameters(ultrasonic amplitude,feed speed and rotational speed).The experimental results are consistent with the conclusion of the plastic deformation model.That is,with the increase of ultrasonic amplitude,the plastic deformation of honeycomb wall increases.With the increase of feed speed,the plastic deformation decreases.The rotational speed has no obvious effect on the plastic deformation of honeycomb wall.The micro and macro morphological characteristics of honeycomb wall are observed and summarized since it is directly related to the processing quality of aluminum honeycomb.In terms of micro-morphology,three characteristics are proposed,i.e.,burr and notch on the boundary,step-like stripes on the surface and morphological difference on the impact surface.The burrs and notches on the boundary decrease with the increase of the ultrasonic amplitude,the width of the step-like stripes increases with the increase of the feed speed,and the morphological difference of the impact surface is mainly affected by the tool rotation.In terms of macro-morphology,firstly the cutting force is studied,and it is found that with the increase of feed speed,the cutting force in all directions increases;with the increase of rotational speed,the cutting force decreases;with the increase of ultrasonic amplitude,the cutting force decreases obviously,so the macro-deformation of honeycomb wall can be effectively reduced by the increase of rotational speed or additional ultrasonic vibration.In the parameters of ultrasonic machining,excessive feed speed will cause crushing and tearing of single-layer honeycomb wall;too small or excessive speed will cause twisting or equidistant burr of double-layer honeycomb wall.