Tool Inclination Research Articles

Tool trajectory planning method for CFRP curved component milling: Considering variable inclination to adapt to different directions of fiber layers

Improper tool trajectory selection during CFRP curved component milling can lead to sudden changes in instantaneous cutting parameters, such as fiber cutting angle, resulting in significant machining damage and profile deviation. In this paper, a novel tool trajectory planning method for CFRP curved component milling is proposed. The key innovation of this method lies in considering the effect of tool variable inclination on fiber removal behavior. Employing the developed method, the influence of trajectories under different tool inclination angles on the milling quality of CFRP surfaces is thoroughly investigated. The results indicate that, to minimize machining damage, an inclination angle within 10° is recommended when the fiber cutting direction is in the range of 0°-60° and 150°-180°. For fiber cutting directions falling within 60°-150°, it is recommended to select an inclination angle above 25°. Additionally, the novel tool trajectory planning method decreases CFRP surface profile errors by over 20 %.

Tool inclination angle designing for low-deformation and high-efficiency machining of thin-wall blade based on edge-workpiece-engagement

The maximum flexibility direction(MFD) is solved for establishing the deformation estimation criterion of the blade during machining process, and the larger the milling force in MFD, the bigger the deformation of the blade during machining process. A new milling force calculation algorithm based on edge-workpiece-engagement(EWE) is proposed by analyzing the contact process between the ball-end milling tool and the chip. The chip thickness of each tool element of each edge curve at any rotation angle is calculated, the milling force of MFD and SLDs under different inclination angles are calculated. The average absolute milling force in MFD reaches the minimum value of 0.65126N when the lead/tilt angle is 30°/-45°, and the maximum machining efficiency is reached when the lead/tilt angle is 45°/-45°.The optimized tool inclination angle, which is 30°/-45° for lead/tilt angle, is obtained by solving the multi-objective optimization problem of machining deformation represented by relative deformation and machining efficiency represented by relative stable machining area. The effectiveness of the proposed scheme is verified by comparison of simulation and experiment for blade machining error under two kinds of tool orientations.

Research on the influence of tool inclination angle and surface curvature on cutting force of ball-end milling mold steel S136

Research on the influence of tool inclination angle and surface curvature on cutting force of ball-end milling mold steel S136

Influence of Tool Inclination and Effective Cutting Speed on Roughness Parameters of Machined Shaped Surfaces

Free-form surfaces in the automotive or aviation industry where the future shape of the product will contain complex surfaces raises the question of how to achieve the necessary shape of the required quality in the milling process. One of the methods of their production is the use of 5-axis milling, in which it is necessary to consider not only the input data of the process itself, but also the methodology for evaluating the desired results. Correctly answered questions can thus facilitate the choice of the inclination of the tool when machining parts of the surfaces defined in the experiment. The primary goal of the paper was to monitor the influence of tool inclination on the quality of the machined surface and effective cutting speed by evaluating surface roughness and surface topography. The experiment was designed to show the effect of different tool positions while the feed per tooth fz for the finishing operation remained constant. The best result in terms of surface quality was achieved with a tool inclination of 15° in the cutting process. The most unfavorable result was obtained with a tool axis inclination of zero degrees due to unfavorable cutting conditions.

Chip geometry modeling in micro-milling of glow discharge polymer by a single-edge diamond tool considering tool inclination

Chip geometry modeling in micro-milling of glow discharge polymer by a single-edge diamond tool considering tool inclination

Study on the influence of milling tool inclination angle on surface quality and optimal selection in the ultra-precision diamond milling of curved surfaces

During the milling of a curved surface, the shape of the curved surface changes continuously along the milling path, and the direction of the angle between the axis of the milling tool and the normal vector of the machined surface also changes. In turn, these changes greatly affect the quality of the machined surface. Therefore, to improve the surface quality of machined workpieces, the milling tool inclination angle should be optimized. In the present study, a three-dimensional model of the milling tool path and the workpiece surface was created. The three-dimensional surface model of the workpiece at each machining moment was iteratively built based on the Z-map method. From the macroscopic perspective, the influences of different milling tool inclination angles on surface roughness were analyzed. The difference in surface roughness generated by different inclination angles under the same feed rate and pitch was obtained. When cutting with the top of the milling tool, the roughness was larger compared to other inclination angles, and there was a roughness deviation of about 8% when other inclination angles were selected. Moreover, from the microscopic perspective, the material removal rate from a single feed cycle and the optimal inclination angle range for milling stability were explored. An optimal inclination range of 15–30% was obtained, considering both the total material removal volume and unit-angle material removal volume. Finally, a spherical machining verification experiment was conducted on an ultra-precision machining tool, and the experimental findings agreed well with the simulation results, demonstrating the reliability of the proposed model. The theoretical model of this study can provide a basis for optimal cutting tool inclination angle selection during complex surface milling.

Examination of surface milling performance of micro-textured ball milling cutter

To cope with the constant change of tool–work contact area caused by the constant change of workpiece surface curvature during machining surface, the tool–work contact area is evaluated, and the mathematical model of micro-texture distribution is constructed. The milling simulation is carried out by ABAQUS software. The obtained results show that the tool inclination angle is the main factor affecting the milling force, and the micro-texture diameter is the leading factor influencing the milling temperature. Subsequently, the milling experiment is carried out, and a reasonably good agreement between the observed data and the simulation results is reported. The artificial fish swarm algorithm is also exploited to optimize the parameters.

Modeling and investigation of minimum chip thickness for silicon carbide during quasi-intermittent vibration–assisted swing cutting

In micromachining, the quasi-intermittent vibration—assisted swing cutting technology alleviates the residual height problem of elliptical vibration–assisted cutting (EVC) and inherits its intermittent machining characteristics. The minimum chip thickness has a significant impact on cutting forces, tool wear, and process stability when working with difficult-to-machine materials. This study thoroughly examines the impact of cutting parameters and tool parameters on the quality of the workpiece during machining in order to better understand the time-varying characteristics of the quasi-intermittent vibration–assisted swing cutting (QVASC) machining process and the size effect on micro-cutting of silicon carbide crystal. This paper created the minimum chip thickness prediction model suited to QVASC machining process. The effects of variables such as cutting velocity and tool inclination on the minimum chip thickness were discussed as well as the scribing tests that were conducted on such challenging materials as silicon carbide. The research findings shown that during the machining process, the critical undeformed chip thickness of silicon carbide decreased continuously as the cutting velocity sequentially increased (1.51 mm/min, 1.88 mm/min, 2.26 mm/min); under the down inclination angle (0–10°), the critical undeformed chip thickness also continuously decreased. These results confirm that cutting too fast reduces the instantaneous undeformed chip thickness, which is not conducive to ductile removal.

Investigation of the influence of the trajectory of shaping movements on the surface roughness by vibroacoustic monitoring during milling

The principles of constructing a system of online monitoring and vibroacoustic diagnostics for milling spatially complex surfaces are considered. The high sensitivity of the vibroacoustic signal is shown when the cutting edges of the milling cutter are passing through the processing zone. An estimate of the influence of the motion trajectory on the roughness parameters is given. Keywords: spherical-cylindrical milling cutter, roughness, vibroacoustic diagnostics, industry 4.0, online monitoring, tool inclination, motion trajectory. 009063@pnu.edu.ru

Effect of the inclined angle of micromilling tool on the fabrication of the microfluidic channel

Micromilling is a common processing method for fabricating microfluidic chips or other microproducts with high processing accuracy and low cost, which is suitable for mass production. The main concern of micromilling is the surface roughness of the work material. However, only a small range of surface roughness can be obtained in the general study of micromilling by changing the processing parameters, which is very difficult to obtain a specific roughness. In the process of micromilling with end mills, due to the structural characteristics of the tool tip, the inclination angle of the tool has a significant impact on the bottom surface of the machined channels. In this work, the influence of the tool inclination on the surface roughness was studied through the inclined micromilling tests of the poly(methyl methacrylate) (PMMA) surface, and it was proposed to realize the control of the machined surface roughness by inclined micromilling. In addition, a theoretical model considering tool inclination was established to calculate the surface roughness of the machined bottom obtained by inclined micromilling. The experimental results were consistent with the theoretical results under the low speeds. Afterwards, the polydimethylsiloxane (PDMS) was used to replicate the microchannel machined on the PMMA surface, and the microfluidic chips were prepared to control the fluid flow in the channel by adjusting the roughness of the bottom of the channel. Results indicated that the smoother channel flowed first under the same flow pressure. The study offers a new idea of surface roughness control, which can be applied to flow control in microfluidic chips.

Brittle‒ductile transition behavior of 6H-SiC in oblique diamond cutting

6H-SiC is a typical hard-brittle material, and the challenge of performing ductile-regime machining in diamond cutting necessitates an in-depth understanding of the brittle‒ductile transition (BDT) mechanism. In this work, a novel machining method named oblique diamond cutting is employed to improve the BDT behavior of 6H-SiC. First, the tool edge ovalization effect is proposed, which provides deeper insight into the change in cutting edge shape evaluated in the cutting plane. An empirical model under the combined influence of the nominal tool rake angle, tool sharpness and tool inclination angle is established to effectively describe the equivalent cutting edge radius of the elliptic-shaped cutting edge in the cutting plane. When the tool inclination angle was increased from 0° to 45°, the equivalent cutting edge radius increases gradually, and the error of the prediction model remained at a low level of less than 7.5%. Second, an oblique plunge cutting experiment and finite element (FE) simulation were carried out under the consideration of tool edge ovalization effect. The simulation results indicate that the BDT depth grew gradually as the tool inclination angle increased, and shows the same changing trend as the experimental results with an average error of 14.9%. When the tool inclination angle was increased to 45°, the BDT depth obtained in experiments doubled (dc = 42.4 nm) compared to the results of traditional orthogonal cutting including from the references and this work. Such a huge improvement in the BDT behavior in cutting is of great significance for the successful execution of ductile-regime machining on a SiC optical component in practice. Finally, the reason for the increase in the BDT depth is revealed to result from changes in the stress distribution in the cutting area due to the increasing equivalent cutting edge radius of the elliptic-shaped cutting edge arc, especially the tensile stress, which is particularly sensitive to brittle materials with insufficient tensile strength. Compared to traditional orthogonal cutting, a high compressive stress zone is formed beneath the tool because more materials undergo the squeezing of the elliptic-shaped cutting edge. Thus, the tensile stress concentrated on the machined surface behind the cutting edge is suppressed, which is beneficial for promoting the plastic deformation of brittle materials with insufficient tensile strength. This is of great significance not only for SiC but also for the processing of other hard-brittle materials.

Effects of tool angles and uncut chip thickness on consumption of plastic deformation energy during machining process

Research on the underlying mechanism that controls the chip deformation and energy consumption is a basis to instruct the cutting process planning and improve the machining efficiency. The metal cutting process can be treated as purposeful separation of workpiece material, and the stress state located at the tool tip has great effect on the fracture of material being removed. Through studying the relationship between the stress triaxiality and chip formation process, this paper aims to reveal the effects of tool rake angle, inclination angle and uncut chip thickness on chip deformation behavior and associated energy consumption during machining of 1045 steel based on finite element method (FEM). A two-dimensional FEM model for orthogonal cutting is developed to study the effect of tool rake angle and uncut chip thickness on chip deformation, while a three-dimensional FEM model for oblique cutting is developed to investigate the effect of tool inclination angle. The parameter of chip compression ratio (CCR) is adopted to assess the chip plastic deformation and energy consumption under varied machining conditions. The cutting force component calculated based on CCR is compared with the total cutting force to demonstrate the dominant role of chip plastic deformation in cutting energy consumption. The results indicate that larger rake angle and smaller inclination angle of cutting tools as well as larger uncut chip thickness lead to increase of stress triaxiality near the tool tip, which can reduce the material fracture strain and be beneficial for the separation of material being removed from the bulk workpiece. This paper will be attractive from both practical and fundamental perspectives devoted to instructing the optimization of cutting parameters to improve the processing efficiency and reduce the energy consumption.

The Effect of Cutting Parameters on Surface Roughness and Morphology of Ti-6Al-4V ELI Titanium Alloy during Turning with Actively Driven Rotary Tools

The titanium alloy Ti-6Al-4V ELI is most commonly used for medical implant products because it is corrosion resistant, high strength, and lightweight. In actuality, the temperature will be very high during the machining of this material. This will accelerate the tool wear and affect the surface roughness. Turning with the actively driven rotary tool (ADRT) has been proven to decrease the cutting temperature so that it is suitable for machining the Ti-6Al-4V ELI. This study focuses on investigating the surface roughness and morphology of Ti-6Al-4V ELI when turning with the ADRT. The surface roughness was measured using the surface profile tester, while the surface morphology was observed using a Scanning Electron Microscope (SEM). The turning with ADRT parameters consisting of the tool diameter, cutting speed, tool revolution speed, feed, and tool inclination angle were analyzed for their effects on the surface roughness. Results show that the cutting speed and tool inclination angle have a significant effect, with a contribution effect of about 67% on the average surface roughness (Ra). The increasing cutting speed resulted in the increased average surface roughness (Ra). The average surface roughness (Ra) also increased with an increasing tool inclination angle. Moreover, no physical damage was observed, such as cracks, micro-pits, and a white layer on the material’s surface morphology.

Analysis of automated surface roughness parameter support systems based on dynamic monitoring

Introduction. Domestic and foreign works on the milling of complex-profile surfaces with a ball-end tool were analyzed. Methods of surface quality control and ways to provide amplitude parameters of roughness, based on research data and field experiments, were considered. Theoretical provisions on the determination of cutting forces and the results of vibroacoustic diagnostics were presented.Materials and Methods. The methods of correlation analysis, comparison and generalization of the results were applied. The data were calculated at different tool angles, taking into account the instantaneous cutting forces, and were fixed in the range of values of the variable feed per tooth (fz) and the angle of inclination of the surface (γ). The vibroacoustic diagnostic data and theoretical data of the presented model at different tool inclination angles were verified by experiment. Consequently, such methods can be used to predict surface roughness parameters.Results. The relationship between cutting forces, tool inclination angle, and vibroacoustic diagnostics data was found. A model of the cutting force and tool displacements was formulated taking into account the inclination of the surface. The optimal range of the inclination angle of the tool to the surface to be machined, at which the minimum values of the amplitude parameters of roughness were achieved, was determined. The sound vibrations obtained empirically, presented in spectral and wave forms, were in good agreement with data from other sources. This allowed us to conclude about the feasibility of forecasting and monitoring roughness parameters in real time through acoustics.Discussion and Conclusions. It was established that the growth of forces in the direction ae(X) and fz(Y) was observed at γ > 40°. This was due to the distribution of the components of the cutting force along the cutting edge and depended on the inclination of the surface. The amplitude parameters decreased when the angle increased from 10 to 40 degrees. The found interrelations of force analysis, processing directions, and vibroacoustic diagnostics have validated the use of vibroacoustic diagnostics to predict surface roughness. Acoustic diagnostics, regardless of the layout of technological equipment, enables to quickly adjust the sound device and assess the impact of cutting modes on roughness parameters.

A roughness calculation method based on milling topography simulation

The surface texture and roughness parameters of the workpiece after milling have a greater impact on the performance of the workpiece, so the analysis of the milling topography is particularly important. Firstly, the edge line of the ball end milling cutter was modeled. According to the movement law of the milling process, a complete set of milling topography simulation model was established, and a new influencing factor phase difference is proposed. In addition to the conventional cutting parameters, the model also considers the phase difference and tool inclination. Secondly, through the topography analysis and the calculation of the height of the convex peak H max, the comparison with the experiment was carried out to further verify the accuracy of the model. Finally, the point cloud data obtained from the topography simulation is processed, the roughness Sa is calculated according to the least square method. and the influence of the phase difference Δφ and the tool inclination β on the milling topography, surface texture and roughness Sa are respectively analyzed. The conclusions obtained provide guidance and reference for industrial parts designers who have specific texture requirements.

Surface deformation, phase transition and dislocation mechanisms of single crystalline 6H-SiC in oblique nano-cutting

Compared with the conventional orthogonal cutting, the oblique nano-cutting of 6H-SiC by tilting the tool at different angles, i.e., the tool inclination angle, is systematically investigated via molecular dynamics (MD) simulations. Focusing on the deformation mechanism, surface deformation including elastic recovery and deformation layer thickness is studied considering the edge ovalization effect in the cutting plane of oblique cutting. Moreover, the variation of cutting force is also analyzed, which relates to the improvement of processing accuracy and the structural phase transition. In particular, the transition path is clarified by coordination number analysis and virtual X-ray diffraction, which shows that the amorphization process is achieved via an initial transformation from the wurtzite structure to a fivefold coordinated orthorhombic intermediate structure, and then to an amorphous phase. Finally, dislocation analysis reveals that the basal dislocation systems dominate the dislocation behaviors, while in oblique nano-cutting especially at the tool inclination angle of 30°, the dislocation system of {0001}<11¯00> (i.e., the basal 1/3<11¯00> Shockley partial dislocation of 6H-SiC) is more activated due to the inclined-cutting-edge-derived shear stress. Furthermore, stacking faults are also formed beneath the bottom of cutting grooves due to the slip upon fivefold coordinated atoms plane.

ROBOT-BASED SURFACE FINISHING OF FORMING DIES CONCERNING DIFFERENT PATH STRATEGIES

The production of shape accurate forming dies in the toolmaking industry requires a high degree of manual labour. To achieve a higher level of automation, machine-based approaches are necessary. Therefore, robot-based milling experiments of difficult-to-machine cold work steel 1.2379 are carried out. This paper presents an experimental study of different path strategies using an industrial robot to mill example geometries of a forming die. Starting with preliminary tests to determine the best possible process and machining parameters, a conventional machining process strategy follows as a reference. Based on the findings two different strategies are derived: additional tool inclination and the avoidance of circular movements that are eventually joined and regarded in combination. Four different path strategies are carried out to determine the influence on form deviation in a CNC-like multi-step material removal process. Results are analysed and discussed regarding geometric fidelity and cutting moments of the example geometries.

Remarkable Characteristics of a Novel Path Interval Determination in Filleted End Milling

This study describes remarkable characteristics of a novel path interval determination in filleted end milling with a tool inclination. CNC milling machine is one of the core technologies in practical manufacturing. Computer-aided technologies have contributed to the technological advancement. Tool path generation in computer-aided manufacturing is really important for CNC milling process. Although there are a lot of parameters treated in tool path generation, path interval is one of the influential factors in considering the balance between manufacturing efficiency and machined surface feature. A path interval determination in filleted end milling commonly entails the intersection problems with mathematical complexities in essence. The related studies have been reported so far, while there has scarcely been a procedure to cope effectively with the complexities. Hence, this study focused on a novel path interval determination proposed in our previous study. After the analytical discussions were made with the computational and experimental results, it was acquired from the explicit evidences that the novel procedure possessed remarkable characteristics contributable for a path interval determination in multi-axis filleted end milling.

FE-SPH hybrid method to simulate the effect of tool inclination angle in oblique diamond cutting of KDP crystal

Due to the soft and brittle characteristic, the potassium dihydrogen phosphate (KDP) crystal undergoes a complex process in diamond cutting, which makes the material removal mechanism is still a subject of controversy. In this paper, based on the machining model of oblique diamond cutting of KDP crystal, the effect of tool inclination angles in machining is numerically investigated by constructing a FE-SPH hybrid model, which combines the finite element (FE) method and smoothed particle hydrodynamics (SPH). Subsequently, oblique fly-cutting experiments with the same tool geometries and cutting parameters are performed, and the topographies of uncut shoulder and finally machined surface are measured by the atomic force microscope (AFM). Results show that the distribution of hydrostatic pressure clearly reflects the susceptibility of the processed surface to the cracks formation. With the consideration of hydrostatic pressure, the simulated results of cracks on the uncut shoulder and finally machined surface present a good consistency with the measured results in experiments. Moreover, the chip flow angle in simulation approximately follows the Stabler's chip-flow rule. As tool inclination angle increases, the width of interference zone decreases and the phenomenon of chip tearing is gradually relieved. Finally, the simulation results and experimental observations confirm that the roughness of finally machined surface is influenced by the average slope of uncut shoulder, the width of interference zone and the distribution of cracks.

Determining a contact spot in the orbital burnishing deformation

The influence of the orbital burnishing main parameters on the configuration, size and area of the plastic contact spot during cylindrical parts processing is studied using SolidWorks software. The computer modeling results show that indent size and contact area are mainly affected by the working tool inclination angle, orbital rotation radius and the penetration depth, while the working tool radius and the workpiece diameter are of less significance.