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Adiabatic Shear Mechanisms for the Hard Cutting Process

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Chinese Journal of Mechanical Engineering 2015年第3期28卷 592-598页

作者： yue caixu WANG Bo LIU Xianli FENG Huize CAI Chunbin State Engineering Laboratory of High Efficiency Cutting and Tool Harbin University of Science and Technology

The most important consequence of adiabatic shear phenomenon is formation of sawtooth chip. Lots of scholars focused on the formation mechanism of sawtooth, and the research often depended on experimental approach. For the present, the mechanism of sawtooth chip formation still remains some ambiguous aspects. This study develops a combined numerical and experimental approach to get deeper understanding of sawtooth chip formation mechanism for Polycrystalline Cubic Boron Nitride（PCBN） tools orthogonal cutting hard steel GCr15. By adopting the Johnson-Cook material constitutive equations, the FEM simulation model established in this research effectively overcomes serious element distortions and cell singularity in high strain domain caused by large material deformation, and the adiabatic shear phenomenon is simulated successfully. Both the formation mechanism and process of sawtooth are simulated. Also, the change features regarding the cutting force as well as its effects on temperature are studied. More specifically, the contact of sawtooth formation frequency with cutting force fluctuation frequency is established. The cutting force and effect of cutting temperature on mechanism of adiabatic shear are investigated. Furthermore, the effects of the cutting condition on sawtooth chip formation are researched. The researching results show that cutting feed has the most important effect on sawtooth chip formation compared with cutting depth and speed. This research contributes a better understanding of mechanism, feature of chip formation in hard turning process, and supplies theoretical basis for the optimization of hard cutting process parameters.

关键词： adiabatic shear FEM simulation hard cutting process sawtooth chip

A review of chatter vibration research in milling

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Chinese Journal of Aeronautics 2019年第2期32卷 215-242页

作者： caixu yue Haining GAO Xianli LIU Steven Y.LIANG Lihui WANG Harbin University of Science and Technology Georgia Institute of Technology KTH Royal Institute of Technology

Chatter is a self-excited vibration of parts in machining systems. It is widely present across a range of cutting processes, and has an impact upon both efficiency and quality in production processing. A great deal of research has been dedicated to the development of technologies that are able to predict and detect chatter. The purpose of these technologies is to facilitate the avoidance of chatter during cutting processes, which leads to better surface precision, higher productivity,and longer tool life. This paper summarizes the current state of the art in research regarding the problems of how to arrive at stable chatter prediction, chatter identification, and chatter control/-suppression, with a focus on milling processes. Particular focus is placed on the theoretical relationship between cutting chatter and process damping, tool runout, and gyroscopic effect, as well as the importance of this for chatter prediction. The paper concludes with some reflections regarding possible directions for future research in this field.

关键词： Chatter Gyroscopic effects Milling Process damping Tool runout

Hardening Effect on Machined Surface for Precise Hard Cutting Process with Consideration of Tool Wear

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Chinese Journal of Mechanical Engineering 2014年第6期27卷 1249-1256页

作者： yue caixu LIU Xianli MA Jing LIU Zhaojing LIU Fei YANG Yongheng State Engineering Laboratory of High Efficiency Cutting and Tool Harbin University of Science and Technology

During hard cutting process there is severe thermodynamic coupling effect between cutting tool and workpiece, which causes quenching effect on finished surfaces under certain conditions. However, material phase transformation mechanism of heat treatment in cutting process is different from the one in traditional process, which leads to changes of the formation mechanism of damaged layer on machined workpiece surface. This paper researches on the generation mechanism of damaged layer on machined surface in the process of PCBN tool hard cutting hardened steel Cr12MoV. Rules of temperature change on machined surface and subsurface are got by means of finite element simulation. In phase transformation temperature experiments rapid transformation instrument is employed, and the effect of quenching under cutting conditions on generation of damaged layer is revealed. Based on that, the phase transformation points of temperature under cutting conditions are determined. By experiment, the effects of cutting speed and tool wear on white layer thickness in damaged layer are revealed. The temperature distribution law of third deformation zone is got by establishing the numerical prediction model, and thickness of white layer in damaged layer is predicted, taking the tool wear effect into consideration. The experimental results show that the model prediction is accurate, and the establishment of prediction model provides a reference for wise selection of parameters in precise hard cutting process. For the machining process with high demanding on surface integrity, the generation of damaged layer on machined surface can be controlled precisely by using the prediction model.

关键词： precise hard cutting hardened mould steel hardening effect damaged layer on machined surface tool wear

Conventional and micro scale finite element modeling for metal cutting process:A review

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Chinese Journal of Aeronautics 2024年第2期37卷 199-232页

作者： Le WANG caixu yue Xianli LIU Ming LI Yongshi XU Steven Y.LIANG Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlanta 30332USA

The metal cutting process is accompanied by complex stress field,strain field,temperature *** comprehensive effects of process parameters on chip morphology,cutting force,tool wear and residual stress are complex and *** element method(FEM)is considered as an effective method to predict process variables and reveal microscopic physical phenomena in the cutting ***,the finite element(FE)simulation is used to research the conventional and micro scale cutting process,and the differences in the establishment of process variable FE simulation models are distinguished,thereby improving the accuracy of FE *** reliability and effectiveness of FE simulation model largely depend on the accuracy of the simulation method,constitutive model,friction model,damage model in describing mesh element,the dynamic mechanical behavior of materials,the tool-chip-workpiece contact process and the chip formation *** this paper,the FE models of conventional and micro process variables are comprehensively and up-to-date reviewed for different materials and machining *** purpose is to establish a FE model that is more in line with the real cutting conditions,and to provide the possibility for optimizing the cutting process *** development direction of FE simulation of metal cutting process is discussed,which provides guidance for future cutting process modeling.

关键词： Conventional and micro scale Finite element simulation Metal cutting process Micro cutting Modeling

Research on Surface Roughness of Supersonic Vibration Auxiliary Side Milling for Titanium Alloy

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 100-111页

作者： Xuetao Wei caixu yue Desheng Hu Xianli Liu Yunpeng Ding Steven Y.Liang Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin 150080China Department of Precision Manufacturing Engineering Suzhou Vocational Institute of Industrial TechnologySuzhou 215104China George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlanta 30332USA

The processed surface contour shape is extracted with the finite element simulation *** difference value of contour shape change is used as the parameters of balancing surface roughness to construct finite element model of supersonic vibration milling in cutting stability *** surface roughness trial scheme is designed in the orthogonal test design method to analyze the surface roughness test result in the response surface *** surface roughness prediction model is established and ***,the surface roughness finite element simulation prediction model is verified by *** research results show that,compared with the experiment results,the error range of the finite element simulation model is 27.5%–30.9%,and the error range of the empirical model obtained by the response surface method is between 4.4%and 12.3%.So,the model in this paper is accurate and will provide the theoretical basis for the optimization study of the auxiliary milling process of supersonic vibration.

关键词： Side milling Axial vibration Ultrasonic milling Finite element simulation Linear regression Surface roughness

Drilling process of indexable drill bit based on Coupled Eulerian-Lagrangian method:A simulation study

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Chinese Journal of Aeronautics 2024年第11期37卷 477-492页

作者： Desheng HU caixu yue Xianli LIU Zhipeng JIANG Yongshi XU Junhui LU Steven Y.LIANG Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlanta 30332USA

42CrMo steel has the characteristics of high strength,high wear resistance,high impact resistance,and fatigue ***,drilling 42CrMo steel has always been a challenging *** indexable drill bit has the advantages of high processing efficiency and low processing cost and has been widely used in the field of aerospace hole *** better understand the machining mechanism of the indexable drill bit,this paper uses the Coupled EulerianLagrangian method(CEL)to simulate the three-dimensional drilling model for the first *** simulation results of the drilling force obtained by the CEL method and Lagrangian method are compared with the experimental *** is verified that the CEL method is easy to converge and can avoid the problem of program interruption caused by mesh distortion,and the CEL simulation value is more consistent with the actual ***,the simulation results of cutting force and blade cutting edge node temperature under different process parameters are *** variation of time domain cutting force,frequency domain cutting force and tool temperature with process parameters are *** study provides a new method for the prediction of cutting performance and the optimization of process parameters of indexable drills.

关键词： 42CrMo steel Coupled EulerianLagrangian method Indexable drill bit Drilling force Process parameters

Research on Cutting Force Modeling and Surface Qualityin the Transition Area of the Mosaic Mold

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振动．测试与诊断 2018年第3期38卷 632-646页

作者： LIU Xianli GAO Haining yue caixu JIANG Nan School of Mechanical and Power Engineering Harbin University of Science and Technology Harbin 150080 China

Aiming at the problem of tool wear and breakage, the low accuracy of machined surface duringthe milling process of automobile panel splicing dies, the cutting force modeling of micro element is carriedout. The cutting chip thickness of each cutting cycle is built as a function of the cutting angle and the shearforce according to the different hardness of machining materials, and a plow force model are obtained underng angles. By introducing a single degree of freedom italic collision model, the Hopkinsontest is used to obtain the elastic deformation δ of the tool workpiece impact under different spindle speeds,sults showforce on the tool in the transition area is obtained. Combining above models together,of milling force in the transition area can be obtained. Experiment and simulation reconslstendirections is studied. Fromcythto prove the accuracy of the model. The surface quality under different feede analysis results of machined surface quality, surfacedifference between workpieces, it is concluded that better surface quality can be obtaineness and heightness and low hardness workpiece. The results provide theoretical support for the optimizationing process in the splicing die of the automobile panel highof the milling process in the splicing die of the automobile panel.

关键词： splicing die impact force model cutting force model surface quality

Influences of Tool Wear on Residual Stress and Fatigue Life of Workpiece in Hard Cutting Process

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Journal of Harbin Institute of Technology(New Series) 2018年第5期25卷 61-69页

作者： caixu yue Lei Zhu Lei Feng Jun Liu Shengyu Hao Guangxu Ren School of Mechanical & Electrical Engineering Harbin Engineering University School of Mechanical & Power Engineering Harbin University of Science and Technology

Tool wear has an important influence on the residual stress distribution on the machined ***,it will influence the fatigue life of finished workpiece. In this research,the hard turning process of hardened die steel Cr12 MoV was studied by using PCBN tool with considering tool wear. Based on the numerical treatment of residual stress,the dispersion and distribution curves of different tool wear were fitted,and the influence mechanism of tool wear on the residual stress distribution of machined surface was *** on the theory of fatigue mechanics and mathematical statistics,the mathematical model for difference of stress dispersion and fatigue life was established. The rotating and bending tests were carried out on the standard parts after cutting process for the workpiece. The influence of tool wear on fatigue life was revealed by fracture surface morphology and fatigue life study. The results provide theoretical support for control of residual stress and the fatigue property of the machined surface under the actual working conditions.

关键词： hard turning process tool wear surface residual stress residual stress dispersion fatigue life

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基于球头铣削方式的淬硬钢最小切削厚度确定

机械工程学报 2017年第1期53卷 180-189页

作者：刘献礼马晶岳彩旭万泉哈尔滨理工大学高效切削及刀具国家地方联合工程实验室哈尔滨150080

汽车覆盖件模具精加工中,精加工余量较小,较小的精加工余量与刀具刃口钝圆半径处于相同数量级,为了实现汽车覆盖件模具的高品质加工,刀具刃口钝圆半径的影响应当引起重视。刀具刃口钝圆半径存在,使得塑性材料加工中存在最小切削厚度,当... 详细信息

汽车覆盖件模具精加工中,精加工余量较小,较小的精加工余量与刀具刃口钝圆半径处于相同数量级,为了实现汽车覆盖件模具的高品质加工,刀具刃口钝圆半径的影响应当引起重视。刀具刃口钝圆半径存在,使得塑性材料加工中存在最小切削厚度,当实际切削厚度小于模具材料最小切削厚度时,刀具与工件之间将出现滑擦,导致汽车覆盖件模具的加工精度和表面质量难以保证。提出一种确定最小切削厚度的新方法,该方法基于球头铣削方式,并验证所提出方法的有效性;以汽车覆盖件模具常用材料淬硬钢AISI D2为研究对象,采用所提出的最小切削厚度确定方法,确定不同硬度淬硬钢AISI D2材料的最小切削厚度值,研究速度效应对淬硬钢AISI D2材料最小切削厚度的影响规律,研究结果表明:在所选切削参数范围内,温度效应对淬硬钢AISI D2材料成屑的影响大于应变率效应的影响,此时随着切削速度的增加,最小切削厚度值增大。

关键词：最小切削厚度模具加工淬硬钢刀具刃口速度效应