Finite Element Modeling And Simulation Of High-speed Cutting For Difficult-to-machining Material Integrating Macro And Micro Physical Characters

Aiming at typical difficult-to-machining materials, such as titanium alloys andnickel-based alloy, finite element modeling and simulation of high-speed cuttingintegrating macro and micro physical characters are carried out. to further understandand to make clear of deformation of grain, the change of the stress, strain, physicalphenomenon, and so on, through high-speed cutting process to reveal influence law ofthe micro structure to cutting force, cutting temperature, etc., for the materialcomposition design under different grain structure and provide theoretical basis for thefine machining effect. In this paper mainly four aspects studied as follows:Firstly, based on image processing technology is used to materials micro structureof digital modeling. The ideal sample is obtained by titanium alloy design andpreparation of metallographic specimen, The basis of study the micro structural digitalmodeling theory, the technology of digital image processing and digital imageprocessing method of morphology is discussed in this paper; the SEM image digitalimage segmentation, image noise elimination, morphology processing, such aspretreatment, realized the complex titanium alloy micro structure SEM images of digitalmodeling. A reliable digital model is provided by research for high-speed cutting offinite element simulation analysis in this part.Then, integrating macro and micro structure finite element modeling andsimulation of high-speed cutting of titanium alloy is carried out. Finite element modelof high-speed cutting of titanium alloy is established by the actual high-speed cuttingprocess analysis and simplification; In high-speed cutting process material large strain,high strain rate, and high temperature characteristics is considered, and the constitutiverelation model of Johnson-Cook is introduced to describe the rapid changes of materialperformance, the constitutive model parameters Johnson-Cook is obtained by the splithopkinson pressure bar (SHPB) experiments, high speed cutting of titanium alloy in theprocess of the constitutive relation model is constructed on the basis of experiments; bymeans of finite element software ABAQUS simulation analyzed high-speed cuttingprocess of titanium alloy, the integration of macro micro structure characteristics of high speed cutting cutting force and cutting temperature data, the serrated chip formation isanalyzed, cutting force and cutting during the construction of the high cuttingtemperature variation curves, the grain deformation of titanium alloy and the chipforming and the influence law of cutting force, cutting temperature, etc. is discussed inthis paper.Furthermore, in order to validate the finite element simulation results, the study oftitanium alloy orthogonal cutting tests is carried out. Right-angle milling experimentbased on orthogonal cutting mechanics characteristic is designed, a special experimentdevice is created, including specimen base, specimen and cutting tools, the titaniumalloy rectangular cutting force and cutting temperature, are measured and analyzed, thechange rule of cutting force and cutting temperature, the test results are compared. Testresults and the high-speed cutting titanium alloy finite element simulation results arecompared and analyzed, the consistency of the two kinds of results verify the validity ofthe finite element simulation results.Finally, in view of the other kinds of typical difficult-to-machining nickel-basedalloy material, the analysis of high-speed cutting finite element simulation integration ofmacro and micro structure using the same technique on the high-speed cutting process iscarried on, high-speed cutting process corresponding to grain structure of thenickel-base alloy GH4169is studied. The results of finite element simulation researchbased on nickel-based alloy chip formation process, the cutting force and high speedcutting process of nickel-base alloy GH4169cutting temperature change curve isestablished, the influence law of the grain structure of nickel-based alloy to the chipformation, cutting force, cutting temperature etc. is discussed.