Research On Ultrasonic Assisted Drilling Of Stainless Steel Plate

With the development of modern industry,stainless steel is widely used in high-tech fields such as nuclear power,aerospace,and medical because of its comprehensive mechanical properties such as excellent corrosion resistance,wear resistance and high strength.The demand for drilling processing of parts is increasing day by day,and the requirements for processing accuracy and processing quality are becoming higher and higher.However,stainless steel is a typical difficult to machine material.Its high plasticity,low thermal conductivity,and cutting characteristics that are prone to chipping make the drilling process increasingly difficult.For the traditional drilling processing technology,due to the large axial force,severe tool wear,chip breaking,and difficulty in chip removal during the drilling process,the quality of the workpiece's machining surface deteriorates,production costs increase,and processing efficiency decreases.Traditional drilling machining has significant limitations.Therefore,in view of the above problems,ultrasonic assisted drilling machining technology was introduced to conduct ultrasonic assisted drilling experiments on304 stainless steel thick plates.From axial force,tool wear,and chips Morphology,micro morphology of the hole wall and surface roughness are analyzed in detail in terms of the effects of ultrasonic assisted drilling processing technology,which provides an experimental basis for academic research and practical application of ultrasonic assisted drilling for difficult to machine materials such as stainless steel.The main research contents of this article are as follows:(1)The removal mechanism of ultrasonic assisted drilling is analyzed.For the ultrasonic-assisted drilling interrupted cutting machining method,a point on the cutting edge is selected to establish a three dimensional coordinate system,the coordinate equation is listed,and the motion trajectory of the point on the cutting edge is plotted and analyzed.Variable speed cutting characteristics of ultrasonic assisted drilling are described.Based on the motion trajectories of the two main cutting edges of the tool,the kinematics analysis of the ultrasonic assisted chip breaking mechanism is performed to obtain the chip breaking conditions.(2)Using finite element simulation,a simulation model of ultrasonic-assisted drilling machining was established,and the magnitude of axial force in the process of ultrasonicassisted drilling and traditional drilling simulation of 304 stainless steel was compared and analyzed.By changing the simulation parameters,the spindle speed,each revolution The influence of dosing and ultrasonic amplitude on the axial force in the simulation.(3)An ultrasonic assisted drilling machining system was established to perform drilling experiments on 304 stainless steel thick plates with or without ultrasonic assistance.The axial force,tool wear and chip morphology of ultrasonic assisted drilling and conventional drilling are compared and analyzed,at the same time,the spindle speed,the feed per revolution and the ultrasonic amplitude are analyzed for the average axial force of the two machining methods.The influence of the force and the comparison between the experimental value of the average axial force and the simulation value verify the validity of the simulation model.(4)The intelligent super depth of field digital microscope and contact surface roughness meter were used to observe and measure the hole wall surface obtained by ultrasonic assisted drilling and traditional drilling.The micro morphology and surface roughness of the hole wall of the workpiece obtained by the two processing methods are compared and analyzed.In addition,the micro hole of the 304 stainless steel workpiece obtained by ultrasonic assisted drilling of the spindle speed,the feed per revolution and the ultrasonic amplitude is also analyzed The influence of morphology and the influence of different processing parameters on the surface roughness of the hole wall obtained by the two processing methods.