Study On Chip Forming Mechanism And Tool Wear In Drilling Superalloy

Superalloy,Because of its high strength and light weight,have been widely used in aerospace and other fields.However,due to the anisotropic characteristics of superalloy material,it is easy to occur in the processing process of burr and other defects,which seriously affect the machining accuracy,especially the drilling;In addition,the material has poor thermal conductivity and high hardness,which lead to serious tool wear during machining;The existence of these problems seriously affects the application and development of superalloy materials in various fields.For the present high temperature alloy materials in the machining problems,in order to find out the drilling of superalloy cutting quantity and chip formation and tool wear,the contents of this subject include the following aspects:First of all,in the study of the basic structure and basic geometric parameters of twist drill,drilling bit of 3D solid model by three-dimensional modeling software UG.Simulation model of drilling bit by using the finite element simulation software DEFORM-3D,using Usui ’s model for the material wear model,set the number of steps,step length,drilling conditions and cutting parameters,selection iteration method and solver,finally achieve the drilling process simulation.Finally,orthogonal experiments were carried out in different cutting parameters and geometric structure,take advandage of the finite element simulation software DEFORM-3D,the data of drilling temperature,tool wear and chip shape can be obtained,and the experimental research platform is built,Two kinds of different cutting tools for high speed steel bit and carbide drill bit.Using the single factor method,obtained different cutting conditions on deformation law of tool wear and chip shape,in the drilling process of different cutting tools and compared the data with the simulation results,we can draw the following conclusions:(1)The wear mechanism of superalloy wear is abrasive wear,adhesion wear,oxidation wear and diffusion wear,and abrasive wear and adhesive wear is the dominant form.(2)The main cutting edge and chisel edge is superalloy GH4169 in high temperature in the process of drilling.Increase speed and feed rate increases,when the speed and amount of feed increases,the heat generated by the speed,temperature,increase tool wear.(3)Increasing the cutting speed and feed rate will aggravate the tool wear,but compared to the two are relative respect,increasing the feed rate show the little effect of the tool wear.The cutting efficiency of drilling superalloy can be improved by increasing the feed rate,which is beneficial to prolong the service life of the cutter and restrain the tool wear.(4)The chip formation of superalloy after drilling is mostly presented as long ribbon spiral chip,When the rotational speed is 1000 /min R,the feed rate is 0 08mm/r,which is the most beneficial to drill the carbide bit.The greater the cutting speed,the smaller the degree of deformation of the chip,more helpful to the formation of chip,The greater the feed rate,the chip deformation coefficient also increases with the increase of the chip shape,the higher the degree of curl,the chip curl radius decreases,and the chip breaking effect is better.In addition,vertex angle and spiral cutter angle effect on the chip form smaller.