Research On Drilling Technology Of GH4169 With Machine-clamped Deep Hole Drill

GH4169 alloy has been widely used in petroleum,aeronautics and astronautics fields because of its excellent corrosion resistance and radiation resistance.However,this material has the characteristics of serious work hardening and large cutting force during the machining,which is a typical difficult cutting material.In this paper,deep-hole drilling technology of GH4169 with machine-clamped tool is researched.Based on simulation and experiment,the influence of different machining parameters on the axial force and torque of BTA tool was studied.The better process parameters of GH4169 are obtained by using machine-clamped tool of deep-hole,which provided technical support for machining.The main contents and conclusions are as follows:First,according to the material characteristics and cutting characteristics of GH4169,the appropriate deep-hole BTA tool is selected,and then the force analysis of tool is carried out to lay a foundation for the simulation test.Second,according to the actual drilling conditions,the contact relationship between the bit and the workpiece is defined,and the geometric model of BTA tool is established.Abaqus software is used to conduct contact analysis and simulation.9 sets position angle data of guide block are selected for simulation,and the contact stress on the guide block changes with the position angle of the guide block is mainly researched.Taking the minimum contact stress as the optimization evaluation index,it is optimized for the position angle of the guide block,and the optimized position angle of the guide block is ?=80°,?=195°.Third,establishing the geometric model of the BTA tool and the workpiece,defining the kinematic relation between the BTA tool and the workpiece according to the actual machining conditions of the deep-hole drill,and using the Abaqus software simulates the drilling process.The study of the changes in axial force and torque of the BTA drill tool under different cutting parameters shows that the impact of the cutting force will be generated due to the cutting edge of the cutter in the initial drilling stage of the drill bit,and the axial force and torque change curve fluctuates greatly.The drill bit entry stage can be divided into four stages: center gear entry,edge gear entry,middle gear entry,and stable drilling.Compared with the speed,the feed has a more significant influence on the axial force and torque,and the axial force and torque increase with the increase of the feed.When the speed is 145r/min and the feed rate is0.09 mm/r,the torque and axial force are both maximized.The speed is 145r/min and the feed rate is 0.05 mm/r,the axial force and torque are the smallest.Considering the efficiency of deep hole processing and the magnitude of axial force and torque,3 sets of better process parameters are selected from the 9 sets of simulation data for deep hole processing experiments.Finally,based on the optimized BTA tool structure and cutting parameters,deep-hole machining experiments are carried out to research the tool wear and failure modes,as well as the law of chip width,thickness and compression rate with the drilling depth.The influence of the initial feed of the drill bit on the deflection of the hole axis is also analyzed.In the end,using tool wear,chip morphology and hole axis deflection as the evaluation criteria,the best process parameters are 145r/min,0.05mm/r;175r/min,0.05mm/r.