Research On The Adiabatic Shear And Plastic Deformation Of Difficult-to-cut Materials In Cutting Process

With the continuous progress of science and technology,especially the rapid development of aerospace technology,the requirements for the structural properties of materials are getting higher and higher.These kinds of new materials generally have superior properties in physical and mechanical,which make them difficult to use.In the field of mechanical manufacturing,they are called difficult materials,and titanium alloy is one of the typical difficult materials.Titanium alloy components are widely used in the field of aerospace.These titanium alloy components have the characteristics of high cutting force and high cutting temperature in the machining process.Adiabatic shear is one of the main failure forms in the process of high-speed deformation in titanium alloy processing.When adiabatic shear occurs,it will also be accompanied by adiabatic shear band,which is caused by large plastic deformation and will lead to uneven distribution of metallographic phase of the material,thus reducing the bearing capacity of the material.The adiabatic shear phenomenon during the processing of titanium alloy will lead to the degradation of the surface quality and affect the fatigue life of the product.Therefore,the study of adiabatic shear in titanium alloy processing is of great theoretical and practical value.In this paper,three kinds of titanium alloy materials with different metallographic structure(TA7: ?,TB6: ?,TC4: ?+?)as the research object,through theoretical analysis and experimental observation,the different titanium alloy material cutting force under different cutting speeds and study the formation mechanism of serrated chip,designed a free tool change of three-phase load tool rest and use it for three types of titanium alloy cylinder style orthogonal cutting experiment,measurement of the three kinds of different cutting speed orthogonal cutting of titanium alloy cutting force,collected the chip under different cutting speeds,the preparation of metallographic specimen,observed under opticalmicroscope and to measure the micro-structure of titanium alloy scraps under different speeds.Main research contents include: main research contents and innovation work are as follows:(1)A set of adaptor for measuring turning force with KISTLER sensor was designed.The experimental results show that the adaptor can be better used for measuring turning force.(2)The variation law and characteristics of cutting forces in the orthogonal cutting process of titanium alloy with three different metallographic structures were studied.(3)The formation law and plastic deformation of serrated cutting during the formation of adiabatic shear in the cutting process of titanium alloy with three different metallographic structures were studied,and the variation law of parameters such as ruler distance and the degree of serrated cutting during the formation of serrated chip was obtained.The experimental results show that when the cutting speed is less than 50m/min,the chip is mainly strip chip,and the cutting force increases with the increase of the speed.When the cutting speed exceeds 50m/min,the saw-tooth chip begins to form,and the cutting force of three titanium alloys decreases in different ranges.In addition,the cutting force of TB6 titanium alloy with the highest titanium content is much higher than that of the other two alloys.