Numerical Simulation And Experimental Research On Ultrasonic Vibrarion Micro-Milling Of SiCp/Al Composite

Compared with traditional single metal materials,particle-reinforced aluminum-based silicon carbide(SiCp/Al)composites have superior comprehensive properties such as high specific strength,low thermal expansion coefficient,wear resistance,heat resistance and good electrical conductivity.This lightweight high-strength material has broad application prospects in the fields of aerospace,automotive industry,semiconductor components,precision optical instrumentation and microelectronic equipment.With the development of technology and the advancement of social needs,miniaturization,portable instrumentation and products have placed higher demands on the manufacture of micro-miniature parts and components.There are many tiny features such as miniature chamfers,micro-protrusions,micro-holes and micro-grooves in micro-miniature parts,and similar micro-features exist in many conventional-sized parts.SiCp/Al composites have great application value in micro-sized parts,but the existence of SiC particles makes the processing process difficult.Ultrasonic vibration micro-milling has the advantages of high processing efficiency,complex machining structure,small cutting force,high machining precision and good surface quality.Ultrasonic vibration micro-milling has the advantages of high processing efficiency,complex machining structure,small cutting force,high machining precision and good surface quality.Therefore,it is of high practical value and significance to explore the processing technology of ultrasonic vibration micro-milling SiCp/Al composites.In this paper,theoretical,simulation and experimental research are carried out by applying ultrasonic vibration along the axial direction of the micro-milling tool to the workpiece.The main research contents are as follows:1.Carry out finite element analysis and simulation study of SiCp/Al composites based on ABAQUS/Explicit for fine cutting and ultrasonic vibration cutting.(1)Establish a two-dimensional orthogonal two-phase micro-cutting simulation model to study the influence of cutting speed and depth of cut on cutting force during cutting,the deformation of SiC particles and Al matrix material,and the Mises stress distribution between the two.It is found that the ultrasonic vibration can effectively reduce the average cutting force,and the vibration cutting force in the feeding direction is more reduced.Under the ultrasonic vibration cutting,the SiC particle breaking probability is greater.(2)The three-dimensional micro-milling simulation model of ultrasonic micro-milling composite material is established.The cutting force variation,chip generation process and deformation mechanism in ultrasonic vibration milling process are deeply studied.The reliability of the model is verified by comparison with experimental data.2.Kinematic analysis of ultrasonic vibration machining and modeling of milling forces.(1)Based on the kinematics theory,the equation of the trajectory of the tool tip is drawn,and the instantaneous undeformed cutting thickness model and the instantaneous milling thickness model are established.(2)By analyzing the source of milling force,the mathematical model of ultrasonic milling SiCp/AL milling force is established,which provides a reference for the subsequent modeling of ultrasonic vibration cutting force.3.The general micro-milling and axial ultrasonic vibration micro-milling test of SiCp/Al composites were carried out by Φ0.8mm two-blade flat-bottom end mill.(1)Exploring the influence of feed rate per tooth,depth of cut and spindle speed on cutting force: The cutting force increases with the increase of feed per tooth and depth of cut,and increases first with the increase of spindle speed.The trend of reduction;the introduction of ultrasonic vibration can effectively reduce the cutting force and the reduction range is between 10% and 50%;(2)Comparing and analyzing the machined surface of the workpiece material,it is found that the ultrasonically vibrated micro-milled bottom groove has a uniform distribution of mesh and fish scales,and surface defects such as shallow pits,holes and scratches are reduced.