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Ultra-precision lapping is widely used in the mass production of various types of high-precision bearing rollers. The lapping quality of the bearing rollers is greatly influenced by the wear behavior of the lapping tool. In this context, this study presents a computational analysis utilizing the Archard wear law and finite element modeling (FEM) to examine the wear behavior of the lapping tool. A wear simulation approach based on the Archard wear law is implemented in the ABAQUS software that works in association with the Arbitrary Lagrange Eulerian adaptive mesh technique and the Umeshmotion subroutine. Initially, the parameters of the Archard wear model are investigated experimentally using the free abrasive lapping device. A numerical 3D finite element model is established in order to obtain the contact pressure distribution, wear volume, wear depth, and wear profile of the lapping tool. The mesh within the wear region of the finite element model is allowed to move independently from the material to maintain the high-quality mesh for simulating material removal. The simulation efficiency is improved by the incorporation of an acceleration factor. Ultimately, the lapping tool is subjected to an examination regarding the contact pressure distribution, wear depth, and alterations in the wear profile. The wear simulation results of the lapping tool can provide significant insights for future run-in and machining processes. [ABSTRACT FROM AUTHOR]

In this paper, a novel double-disc straight groove lapping (DDSGL) method is proposed to reduce roundness error and improve surface roughness of tapered rollers. According to the conjugate surface principle and the kinematic characteristics of the tapered roller, the theoretical contour of the grinding tool working surface was designed. The contact relationship between the rollers and the working surface of the grinding tool is established. The relative motion between the tapered rollers and the grinding tool is discussed in detail, and the lapping trajectory on the rolling surface of tapered rollers is calculated and analyzed. The impact of the system's structural parameters (i.e., eccentric circular groove radius, eccentricity, and upper disc circular groove radius) as well as the kinematic parameters (lower disc rotational speed) on the uniformity of the lapping trajectory in the lapping process was explored. The structural parameters of the DDSGL equipment were determined using the standard deviation of the lapping trajectory distributed on the tapered roller rolling surface. Finally, the lapping experiments of tapered rollers were carried out in a homemade equipment, and the results show that the newly proposed method can effectively improve the roundness and reduce the surface roughness of the tapered rollers. [ABSTRACT FROM AUTHOR]

Bearings are an important part of the aviation equipment. The working accuracy, performance, service life, and reliability of bearings directly determine the performance of the aviation equipment. The manufacturing accuracy has been gradually improved with the ELID (electrolytic in-process dressing) grinding technology. The grinding-wheel wear has been an unavoidable problem in the ELID grinding of ball-bearing raceways. The ELID grinding-wheel profile needs to be promptly reshaped as soon as its profile deviation is greater than the allowable range. So far, few literatures are concerned about the precision evolution of the grinding-wheel profile under ELID conditions. There are no ready-made standards or instructions for the nonstandard ultra-precision bearings. Even the quality consistency is hard to be achieved. In this research, it aims to balance the service life of the grinding wheel and grinding accuracy. A comprehensively evaluating model is established, which includes two submodels. One is the contour-error submodel for assessing the groove raceway of bearings, in which the precision evolution principles are developed to work as the basis for this submodel. The other is the radial-wear rate submodel for evaluating the precision evolution of the ELID grinding wheel. In submodel 2, a special device is designed and established for the in situ monitoring of the radial-wear rate of the ELID grinding wheel under ELID conditions. It expands the application field of the precision-evolution principle for manufacturing the nonstandard bearings with ultrahigh precision. The rationality of the comprehensively evaluating model is verified by a group of optimal parameters derived from the five-factor-four-level orthogonal experiments. The conclusions can provide an important reference for balancing the wear of the grinding wheel and the grinding accuracy. [ABSTRACT FROM AUTHOR]

Centerless grinding is the main technology for mass processing of rotary parts, which can improve the roundness of rotary parts. With the demand for higher levels of roundness accuracy (within 0.3 μm), the development and operating costs of centerless grinding machines have increased dramatically. Taking cylindrical roller of bearing as research object, a new lapping process of double-disc arc-contact lapping (DDACL) is presented in this work. On the processing mechanism, it is expounded how DDACL overcomes the three fundamental technical difficulties of centerless grinding process in geometric lobing, workpiece instability and work-regenerative chatter vibration, and the unique rounding mechanism of DDACL process is established. At the same time, the machine has simple structure, low precision requirement, and low cost. After lapping with 45 steel groove on the developed test bench, the roundness accuracy of the cylindrical roller is effectively controlled within 0.2 μm, and the accuracy of some rollers can even reach 130 nm, which has significant precision advantages. According to the established DDACL rounding mechanism, the influence of 45 steel and PTFE groove material and electromagnetic driving force on the rounding speed of parts in the test is well explained. The process method proposed in this work paves the way for improving the roundness accuracy of other rotary parts, such as those seen in tapered roller and spherical roller. [ABSTRACT FROM AUTHOR]

In order to study the friction and wear properties of cast iron in free grinding environment under the condition of line contact, this paper presented a new method to calculate the friction coefficient by measuring the friction torque. Through the self-developed free abrasive grinding experimental device in line contact condition, this work carried out friction and wear experiment with relative speed, load, abrasive particle diameter, and abrasive mass fraction as process parameters, and studied the evolution rules of friction coefficient and wear amount of cast iron materials under different process parameters. Based on the response surface method Box-Behnken experimental design, the significance of the experimental results was analyzed, and the prediction model of the friction coefficient and wear amount of cast iron was established. According to the significance of the prediction model, the influence degree of each process parameter on the friction coefficient and wear amount was revealed. The results showed that under the action of free abrasive, the friction coefficient of cast iron material in line contact with GCr15 was between 0.18 and 0.35. When the experimental time was 1.5 h, the removal amount of cast iron material was between 20 and 65 mg, which is significantly increased compared with that without abrasive and the wearing capacity of cast iron increased with the increase of relative speed, load, abrasive particle diameter, and abrasive mass fraction. The friction coefficient had a negative correlation with relative speed, and a positive correlation with abrasive particle diameter and abrasive mass fraction. With the increase of load, the change of friction coefficient decreased first and then increased. The influence degree of each process parameter on the friction coefficient and wear amount of cast iron material: the particle diameter and relative velocity of abrasive were relatively significant, the abrasive mass fraction was the second, and the load was the smallest. Through random experiments, the prediction model of friction coefficient and wearing capacity were verified to be highly accuracy, and could be used to predict the friction and wear performance parameters of cast iron in the process of free grinding under the condition of line contact. It provided a certain theoretical basis for the friction and wear behavior of cast iron as a grinding tool material in the grinding process. [ABSTRACT FROM AUTHOR]

Rolling bearings are extensively employed in the modern machinery industry and are critical industrial base elements. The machining accuracy of bearing rolling elements has a great impact on the service performance of rolling bearings. In this work, advances in the ultra-precision machining of bearing rolling elements are summarized, and corresponding outlooks are presented. An introduction to the accuracy requirement of the rolling element and the corresponding basic principles are first discussed. Subsequently, advancements in the ultra-precision machining of bearing balls are reviewed and analysed. Meanwhile, research progress on the ultra-precision machining of bearing rollers is also summarized and compared with the investigations on bearing balls. It is demonstrated that due to the absence of an intercomparison effect in the machining process, the batch accuracy of the bearing roller is lower than that of the bearing ball. Furthermore, more attention should be given to the machining accuracy of the crown profile and spherical datum surface of the bearing roller. Finally, in regard to the above academic achievements, conclusions and outlooks on the ultra-precision machining of bearing rolling elements are given. The advances and outlooks summarized in this work are beneficial to both academic scientists and industrial researchers. [ABSTRACT FROM AUTHOR]

This paper proposes a modeling method for oxide-film thickness to determine the quantitative relationship between the current and oxide-film thickness in electrolytic in-process dressing (ELID) grinding with workpiece swing. Using this method, the generation thickness of the oxide film per unit time was calculated based on Faraday's law. The oxide-film thickness was calculated using current integration to determine the quantitative relationship between current and oxide-film thickness. Based on the ELID grinding experiment with workpiece swing, the influence of different swing parameters on the oxide-film thickness was analyzed, and the formation mechanism of the oxide film was obtained. The calculation results indicated that as the current decreased from 2.96 to 0.17 A, the oxide-film thickness increased from 0 to 52.79 μm. The experimental results indicated that as the swing amplitude increased from 10° to 30°, the current increased from 1.45 to 2.51 A, and the oxide-film thickness decreased from 33.89 to 24.58 μm. As the swing angular velocity increased from 5 to 15°/s, the current increased from 1.42 to 2.33 A, and the oxide-film thickness decreased from 34.15 to 26.68 μm. Elucidation of the oxide-film formation mechanism can provide a theoretical basis for improving the surface quality of arc grooves. [ABSTRACT FROM AUTHOR]

This paper proposes an electrolytic in-process dressing (ELID) grinding method with workpiece swing to solve the problem associated with the duplication of profile errors between the wheel and groove in the cut-in ELID grinding process. In this work, the arc trajectory feed and ELID grinding were combined to improve the profile accuracy of the arc groove. Furthermore, subject to the new process conditions, a trajectory equation was established by analyzing the movement of the wheel relative to the groove surface, and a trajectory simulation was conducted according to the trajectory equation. Based on the comparative experiment of ELID grinding with workpiece swing and cut-in ELID grinding, the profile shape and shape error of the groove surface were compared and analyzed at different process conditions. The experimental results showed that in cut-in ELID grinding, the shape error (Pt) was 1.0551 μm. In ELID grinding with workpiece swing, Pt increased from 0.4316 to 0.7887 μm as the swing amplitude increased from 10° to 30°. As the swing angular velocity increased from 5 to 15°/s, Pt decreased from 0.9701 to 0.4789 μm. Under the new process conditions, both the wheel surface and groove surface demonstrated a uniform wear mechanism along the groove profile direction. The profile accuracy of the groove surface could be improved, and the profile accuracy of the wheel surface was ensured. The proposed method offers considerable advantages pertaining to the improvement of the profile accuracy of the arc groove. [ABSTRACT FROM AUTHOR]

This work firstly evaluated the machinability of ultrasonic vibration helical milling (UVHM) process on the multilayer carbon fiber reinforced polymer (CFRP)/Ti-6Al-4V stacks, comparing with conventional helical milling (HM). Cutting force, hole edge quality, hole surface morphologies, hole dimensional accuracy, and tool wear were presented to analyze the effect of UVHM on the hole-making performance of stacks structures. The axial forces in machining of CFRP phase and Ti-6Al-4V alloy in UVHM were 2.62–19.92% and 0.95–8.44% less than those in HM, respectively. The hole edge quality and hole surface morphologies of CFRP phase in stacks was improved in UVHM, which is caused by the periodic shear effect between the cutting edge and fibers due to the ultrasonic vibration. The delamination damages of CFRP phase in UVHM were slightly improved compared with that in HM. The delamination factor in UVHM was slightly less than that in HM. The hole diameter error decreased with the increasing number of holes in both HM and UVHM, and the diameter error in UVHM was larger than that in HM. Due to the existence of interface in the stacks structure, the diameter of CFRP phase increase and the diameter of Ti-6Al-4V alloy decrease with the increase of axial depth. The average flank wear of the bottom cutting edge in UVHM was 2.14–19.28% less than that in HM. The main wear mode in HM and UVHM was adhesive wear, diffusion wear, and oxidation wear. However, the adhesive wear was alleviated due to the micro-impact effect and friction behavior caused by the separated cutting characteristic in UVHM. These improvements of hole quality indicated that UVHM is feasible in improving hole quality and tool life for hole-making of multilayer stacks. [ABSTRACT FROM AUTHOR]

High-speed cutting (HSC) and ultra-high-speed cutting (u-HSC) (6.07–32.7 m/s) tests of Ti-6Al-4V alloy were developed based on an improved Split Hopkinson Pressure Bars (SHPB) system. Specific cutting energy was calculated and scaling effect was observed in HSC with different uncut chip thicknesses (20–200 μm). Considering time-dependent (in situ and ex situ) microstructure and mechanical parameters, chip morphology, adiabatic shear band (ASB), chip-free surface, material separation characteristic at chip-workpiece interface, and surface integrity were investigated. The micro-hardness within ASB was 25% higher than that outside of the ASB. Ultra-fine grains (77% grain sizes less than 330 nm) and micro-texture were observed by electron backscattering diffraction (EBSD) test. Grain refinement in ASB was explained by rotation dynamic recrystallization. The maximum shear strain and the range of shear strain rate in ASB at the condition of v = 10 m/s and t1 = 100 μm were approximately 17 and 6.44 × 106 s−1–8.5 × 106 s−1, respectively. Severe plastic deformation was observed by the dimples at ductile fracture surface along ASB. Mechanism of parabolic and ellipsoid dimples caused by shear and tensile stresses was explained for HSC of Ti-6Al-4V alloy. Additionally, the micro-hardness of machined subsurface and the ASB (ex situ parameter) exhibits a relationship with specific energy (in situ parameter), which can provide an effective way to control the formation of ASB and surface integrity by the control of in situ parameters in HSC and u-HSC conditions. [ABSTRACT FROM AUTHOR]

The requirement of high-speed and high-precision contouring with NURBS tool path to the CNC machining process is increasing. The calculation of the contouring error (CE) of the NURBS tool path to real time is necessary for the advanced contour control like the cross-coupled controller (CCC). Based on the complexity of the CE calculation of NURBS, most studies use estimating methods to approximate the real CE in the controller. However, when the cutter is at the large curvature zones in the high-speed machining, the difference between the estimated the CE and the real one becomes large. To solve this problem, an algorithm to calculate the exact CE of NURBS tool path to real time is proposed. The calculation model of the CE of NURBS is derived. Also, the numerical calculation algorithm from Brent's method is given to solve the CE model. Multiple solutions of CE model is discussed and real-time solution tracking method is developed to determine the intervals of the candidate solutions for numerical calculation. Contour error for control (CCE) is proposed for controller design to improve the stability of contour control, which is different from the definition of conventional control error for measurement (MCE). The proposed algorithm is validated for both the simulation and the experiment on the X–Y table. Experimental results show the effectiveness of the proposed algorithm and the actual CE is reduced significantly compared with other methods. [ABSTRACT FROM AUTHOR]

Surface quality of workpiece could be significantly improved by ELID grinding. However, ELID grinding bearing outer ring raceway with small inner diameter has small space, which limits installation of electrode. In this work, ELID grinding bearing outer ring raceway acting as cathode is proposed. But electric spark discharge will occur in ELID grinding with workpiece-cathode, which affects grinding quality. The purpose of this work is to investigate formation mechanism of electric spark discharge and influence of oxide layer on grinding quality. A novel experimental method is proposed to study state of oxide layer (mainly thickness and compactness) in ELID grinding bearing outer ring raceway with workpiece-cathode. Experimental results show that electric spark discharge occurs with thick oxide layer (characterized by control current), resulting in corroded pits on surface of oxide layer and workpiece in ELID grinding with workpiece-cathode. With increased control current, surface of oxide layer becomes smooth. Moreover, grinding force increases with increased control current. When control current is 0.5 A, surface roughness of workpiece is the largest. And surface roughness of workpiece increases with increased control current, as control current is greater than or equal to 1 A. The results are helpful to apply ELID to grind bearing outer ring raceway and improve ELID grinding performance. [ABSTRACT FROM AUTHOR]

Compared with conventional hole-making process, rotary ultrasonic machining (RUM) is commonly believed to improve the cutting performance, such as low cutting force, good hole quality, long tool life, and high material removal rate. However, this work proposes an interesting observation on hole-making process using longitude-torsional ultrasonic assisted helical milling (LT UAHM). Due to the special kinematic motion in LT UAHM, the trajectory of the cutting tool has complex characteristics which may generate a negative effect on machining performance. In this study, a comparative experiment between LT UAHM and conventional helical milling (HM) was carried out. The results showed that the axial cutting force is not always reduced, the machined hole quality is also not improved consistently in LT UAHM. To comprehend the cutting mechanism of LT UAHM incisively, a kinematic trajectory model was proposed. By the theoretical kinematic trajectory model, LT UAHM can generate the ultrasonic elliptical cutting in the process, and the phase shift is a critical factor that can affect the elliptical trajectory shape even the vibration cutting direction of the tool's cutting edge. The equivalent cutting angle and direction of friction between the rake face and chip in processing change accordingly. As a result, the magnitude of cutting force and machined hole quality in terms of burr height in this process will be significantly affected. [ABSTRACT FROM AUTHOR]

Edge surface grinding has been widely applied in achieving functional surfaces and repairing the damage surfaces of carbon fiber-reinforced plastic (CFRP) composites especially with complex three-dimensional features. The conventional surface grinding (CSG) usually generates surface damages, leading to reduced service life and load-carrying capability of the parts. Therefore, there is a critical need to develop a surface grinding process of CFRP composites in a high-quality and high-efficiency way. Rotary ultrasonic machining (RUM) surface grinding has been proven to be such a process. In addition, RUM edge surface grinding can be conducted by up surface grinding or down surface grinding. However, the difference between up surface grinding and down surface grinding with RUM has not been reported. In this paper, the comparison between up surface grinding and down surface grinding with RUM is studied for the first time. The effects of the grinding parameters on machining performance, including cutting force, surface roughness, and surface morphology characteristics, are experimentally studied. The results show that the cutting forces in up grinding are obviously larger than those in down grinding. Lower surface roughness is generated by down grinding when grinding parameters are kept unchanged. The reasons for the differences of cutting forces and surface integrity are discussed. Surface morphologies suggest clearly that brittle fracture is the predominant material removal mode in grinding of CFRP composites. The chip size of the resin, the fracture size of the carbon fiber, and the material removal scale are smaller in down grinding. Furthermore, compared with CSG, the advantages of RUM surface grinding are presented. This investigation will provide useful guidance for surface grinding of CFRP composites. [ABSTRACT FROM AUTHOR]

As a relatively new grinding technology, ELID (electrolytic in-process dressing) is widely used in some businesses. The oxide layer plays an important role in ELID grinding performance. The purpose of this work is to investigate the state of the oxide layer on ELID grinding wheel surfaces based on workpiece-cathode and tool-cathode. The thickness and surface topography of the oxide layer were measured from ELID grinding experiments based on workpiece-cathode and tool-cathode in different controlled dressing current. The normal grinding force was also compared in ELID grinding with workpiece-cathode and tool-cathode. According to the results, there are some caves on the surface of the oxide layer in ELID grinding with workpiece-cathode. With increasing controlled dressing current, the surface of the oxide layer becomes discontinuous in ELID grinding with workpiece-cathode. And the surface of the oxide layer becomes smoother with increasing controlled dressing current in ELID grinding with tool-cathode. Meanwhile, it was found that the oxide layer in ELID grinding with workpiece-cathode is thicker than that in ELID grinding with tool-cathode. Moreover, the normal grinding force in ELID grinding with workpiece-cathode is smaller than that in ELID grinding with tool-cathode. The results are helpful to improve the ELID grinding performance and apply ELID grinding technology with workpiece-cathode to abroad industrial applications. [ABSTRACT FROM AUTHOR]

The groove profile of ball-bearing raceway is of vital importance to ensure the bearing transmission accuracy. It is an attempt to apply electrolytic in-process dressing (ELID) groove grinding for the ball-bearing raceway finishing process. The wear rate of the grinding wheel is directly related to the profile accuracy of the bearing raceway. In order to maintain a high-forming accuracy, the interrupt truing has to be performed at the grinding interval. However, how to rationally plan the grinding interval for high-forming accuracy is hard to resort to the general concept of the wear of the grinding wheel. This study recorded the raceway profile variation on axial direction and radial direction by monitor points. The results show that the raceway profile variation (monitor points) on the axial direction could be omitted, because it is far less than the profile variation (monitor points) on radial direction. An evaluation method was proposed to plan the interrupt truing based on the raceway profile variation (monitor points) on radial direction. Finally, the feasibility of the proposed evaluation method was verified by the experimental results. The evaluation method of forming accuracy could provide a reference for selecting the truing interruption during ELID groove grinding process. The approach that incorporates the interrupt truing with the ELID groove grinding enriches bearing manufacturing method. The ELID groove grinding has a great potential for application in precision machining of ball bearing ring raceway. [ABSTRACT FROM AUTHOR]

The present article established empirical models of tool life, residual stress, and surface roughness according to titanium alloy milling parameters. The empirical models were utilized for optimization of production cost and surface quality. As the effects of milling parameters on production cost and surface quality are conflicting in nature, the multiobjective optimization problem in titanium alloy milling was proposed. Considering different industrial demands, two optimization objectives were established, optimization objective I aims to minimize the production time per piece and the number of consumed tools, the objective II aims to minimize the production time per piece, surface roughness, and absolute value of residual stress. In addition, the coupling of the two optimization objectives is considered to optimize the production cost and surface quality simultaneously. Nondominated sorting genetic algorithm-II (NSGA-II) was adopted to solve the multiobjective optimization problem and the optimized results were obtained by the Pareto-optimal solutions. These pareto-optimal solutions were used to conduct the verification experiments. Comparison of experimental and optimized results shows that the relative errors of tool life, surface roughness, and residual stress are less than 5, 7, and 5 %, respectively. The achieved results can provide the beneficial guidelines for the engineering applications depending upon industrial demands. [ABSTRACT FROM AUTHOR]

This paper represented a three-dimensional heat transfer model which describes the temperature distribution with the time variation in solid with conduction-convection boundary during the helical milling process. On the basis of the kinematic mechanisms of helical milling, two types of heat sources were presented; one was the first heat source (FTHS) resulting from the peripheral cutting edge, and the other one was the second heat source (STHS) resulting from the bottom cutting edge. Both effects of the FTHS and the STHS on the temperature distribution of the workpiece were investigated. The FTHS was defined as one semicircle which acted on a helical path; the STHS was defined as one straight line and the movements of which consisted of three ways: rotating around the axis of the tool, turning around the center of the hole, and moving along the axial direction. In order to accurately study the heat transfer model, a stationary coordinate established in the hole and a moving coordinate established in the heat source were developed. The transformation of coordinates and the trajectory of the moving coordinate had been illustrated. Under the two coordinates, a nonhomogeneous partial differential equation (PDE) containing heat source term was derived and was solved using the Green function approach. The heat source term was depicted using the Dirac delta function. A series of experimental tails for Ti-6Al-4V were organized. The experimental results agreed well with the data calculated using the model. The effects of different cutting parameters on the temperature rise were also investigated. [ABSTRACT FROM AUTHOR]

The oxide layer state directly relates to machining quality in electrolytic in-process dressing (ELID) grinding. In this paper, intermittent grinding control strategy was used to monitor and control the state of the oxide layer in interval ELID (ELID II) grinding. Some experiments were implemented based on active control of the oxide layer state. The influence of dressing current, wheel speeds, and grit size on surface roughness and waviness has been discussed in detail with ELID II grinding for bearing steel. The experimental results illustrate that the ELID II method can realize a stable grinding process based on active control of the oxide layer state. The surface roughness (Ra) and waviness (Wa) increase with increase of the dressing current. When the dressing current is constant, Ra and Wa reduce as wheel speed increases and decrease as grain size of wheel decreases. The experimental results also show that sufficient abrasive protrusion can be ensured in ELID II grinding, especially for grinding with a W2.5 super-abrasive wheel which may produce a very smooth surface quality, Ra 0.0166 μm and Wa 0.018 μm. [ABSTRACT FROM AUTHOR]

The prediction of cutting forces is important for the planning and optimization of machining process in order to reduce machining damage. Helical milling is a kind of hole-machining technique with a milling tool feeding on a helical path into the workpiece, and thus, both the periphery cutting edges and the bottom cutting edges all participated in the machining process. In order to investigate the characteristics of discontinuous milling resulting in the time varying undeformed chip thickness and cutting forces direction, this paper establishes a novel analytic cutting force model of the helical milling based on the helical milling principle. Dynamic cutting forces are measured and analyzed under different cutting parameters for the titanium alloy (Ti-6Al-4V). Cutting force coefficients are identified and discussed based on the experimental test. Analytical model prediction is compared with experiment testing. It is noted that the analytical results are in good agreement with the experimental data; thus, the established cutting force model can be utilized as an effective tool to predict the change of cutting forces in helical milling process under different cutting conditions. [ABSTRACT FROM AUTHOR]

A Johnson-Cook material model with an energy-based ductile failure criterion is developed in titanium alloy (Ti-6Al-4V) high-speed machining finite element analysis (FEA). Furthermore, a simulation procedure is proposed to simulate different high-speed cutting processes with the same failure parameter (i.e., density of failure energy). With this finite element (FE) model, a series of FEAs for titanium alloy in extremely high-speed machining (HSM) is carried out to compare with experimental results, including chip morphology and cutting force. In addition, the chip morphology and cutting force variation trends under different cutting conditions are also analyzed. Using this FE model, the ductile failure parameter is modified for one time, afterword, the same failure parameter is applied to other conditions with a key modification. The predicted chip morphologies and cutting forces show good agreement with experimental results, proving that this ductile failure criterion is appropriate for titanium alloy in extremely HSM. Moreover, a series of relatively low cutting speed experiments (within the range of HSM) were carried out to further validate the FE model. The predicted chip morphology and cutting forces agree well with the experimental results. Moreover, the plastic flow trend along an adiabatic shear band is also analyzed. [ABSTRACT FROM AUTHOR]