Ultrasonic Elliptical Vibration Research Articles

Effect of amplitude on material removal behavior and surface formation in ultrasonic elliptical vibration cutting of tungsten heavy alloys

Effect of amplitude on material removal behavior and surface formation in ultrasonic elliptical vibration cutting of tungsten heavy alloys

Machining mechanism of CoCrFeNiAlX high entropy alloys via ultrasonic elliptical vibration cutting

Abstract This study investigates the micro-cutting mechanism of CoCrFeNiAl X high entropy alloys, focusing on the impact of amplitude, vibration frequency, cutting depth, and the Al element content. The mechanical response of the material is analyzed using simulation methods for both conventional cutting and ultrasonic elliptical vibration assisted cutting (UEVAC). The results show that under different vibration parameters and cutting depth, the cutting temperature produced by UEVAC is significantly higher than that of conventional cutting temperature. When the Y-axis amplitude is reduced from 90 μm to 30 μm, the cutting temperature is reduced by 50%. In addition, the cutting temperature is positively correlated with the Al content, and when the molar ratio is 20%, the cutting temperature is about 2.1 times that of 13%. While keeping the cutting parameters unchanged, the cutting force generated by UEVAC is significantly reduced compared to conventional cutting. It is worth noting that when the X-axis amplitude is 40 μm, the Y-axis amplitude is 90 μm, and the vibration frequency is 25 KHz, the cutting force of UEVAC is the smallest, which is only about 13% of the conventional cutting force. With the increase of the mole ratio of aluminum in the high entropy alloy, when the mole ratio of aluminum increases from 0% to 13%, the cutting force begins to decrease by about 33%. However, when the molar ratio increases from 13% to 20%, the cutting force increases by about 214%. On the surface of the workpiece (within the range of 0–3 μm from the machining surface), the residual stress generated by UEVAC is mainly manifested as compressive stress or tensile stress, which is significantly less than the residual stress generated by conventional cutting. The relation of residual compressive stress of workpiece under different aluminum content is Al1 > Al0.6 > Al0.

Study on the influence of ultrasonic elliptical vibration cutting on the micro-cutting mechanism of FeCoCrNiAl0.6 high-entropy alloy

Study on the influence of ultrasonic elliptical vibration cutting on the micro-cutting mechanism of FeCoCrNiAl0.6 high-entropy alloy

Coupling CPFE-CA simulation for grain refinement in ultrasonic elliptical vibration diamond cutting of polycrystalline Cu

While microstructure evolution is commonly observed in severe plastic deformation of polycrystalline metals, modulating the cutting-induced grain refinement in subsurface of polycrystalline metals is promising for promoting the performance of machined surface. In this study, we demonstrate the effectiveness of applying ultrasonic vibration assistance (UVA) in effectively prompting grain refinement of polycrystalline Cu in ultra-precision diamond cutting by experiments and multiscale coupling simulations. Specifically, ordinary cutting (OC) and ultrasonic elliptical vibration-assisted cutting (UEVC) experiments of polycrystalline Cu are carried out, and subsequent cross-sectional characterizations of microstructure evolution in subsurface by metallurgical microscope and electron backscatter diffraction, as well as instrumented nanoindentation tests, are performed, which demonstrates significantly promoted grain refinement in subsurface and increased machined surface hardness by UVA, due to increased dislocation density that is beneficial for the nucleation and growth of dynamic recrystallization. In particular, the multi-scale coupling of crystal plasticity finite element (CPFE) simulation and Cellular Automata (CA) method is firstly established for exploring the microstructural evolution during UEVC and OC of polycrystalline Cu, which is capable of elucidating the underlying correlation of grain refinement behavior in subsurface with characteristics of stress and strain fields in cutting area. Furthermore, the influence of amplitude on the propensity of grain refinement is experimentally and theoretically evaluated, which suggests a critical amplitude of 4 μm that leads to a maximum reduction in grain size by 80.9% and a maximum increase in machined surface hardness by 55.8% in UEVC from that in OC, because of the most pronounced strain accumulation and dislocation activity. The findings reported in this study demonstrate the effectiveness of applying ultrasonic vibration assistance for modulating the grain refinement accompanying strengthening of machined surface in ultra-precision diamond cutting of polycrystalline metals.

Investigation on two-dimensional ultrasonic vibration plane turning method based on elliptical plane swinging strategy along short axis

In the ultrasonic elliptical vibration cutting (UEVC) process, the surface morphology suffers from the large fluctuation of ridge height and residual height, which has restricted the development of UEVC technology. Therefore, on the basis of the elliptical plane swinging strategy along a short axis, a surface topography improvement method (i.e., swing ultrasonic elliptical vibration turning (SUEVT)) for two-dimensional ultrasonic vibration plane turning is proposed in this study. The core idea of the method is to swing the ultrasonic elliptical vibration plane along the short axis to form a machining inclination angle, which reduces the ridge height of the machined morphology to a certain extent, thereby optimizing the surface microstructure and reducing the surface roughness. First, this study establishes a mathematical model of the tool tip trajectory of ultrasonic elliptical vibration under different swing angles, theoretically analyzes the influence of swing angles on the tool tip trajectory and surface topography, and provides a theoretical basis for revealing the surface topography formation mechanism of SUEVT. Second, an engineering practice scheme of SUEVT is proposed, and a processing experiment platform is built. Finally, cutting experiments of SUEVT for TC4 titanium alloy were conducted, studying the influence of swing angles on surface topography and roughness and assessing the feasibility of the method. Results showed that compared with ultrasonic elliptical vibration turning (UEVT), SUEVT has certain advantages in improving surface morphology. When the swing angle of SUEVT is 15°, the surface roughness decreases the most, reaching 19.00 %. Under the condition of SUEVT θ = 15°, the surface roughness decreases first and then increases with the increase in spindle speed, while it is proportional to the feed speed and ultrasonic power. The method proposed in this study can provide new methods and new ideas for ultrasonic elliptical vibration high surface quality machining.

Finite element analysis and experimental study on the cutting mechanism of SiCp/Al composite in laser ultrasonic elliptic vibration turning

SiCp/Al composites have excellent material properties and are increasingly being used in the aerospace, military, and electronic packaging industries. However, the inhomogeneity and non-conductivity of conventional turning (CT) results in poor material surface quality and high cutting forces, which seriously hinder the application of particlereinforced metal matrix composites. The thermal softening property of laser-assisted turning (LAT) and the intermittent cutting property of two-dimensional (2D) ultrasonic elliptical vibratory turning (UEVT) offer unique advantages in improving material surface quality. Therefore, a novel laser ultrasonic elliptical vibratory turning (LUEVT) machining technique is proposed to improve the machining of SiCp/Al composites with two different volume fractions. The effect of highfrequency intermittent machining on material processing was further investigated by adjusting the pulsed laser power. Finite element modelling was used to predict the machining state, surface roughness, and chip morphology between the workpiece and the PCD tool. The effects of varying the machining parameters during the experiment on the two composites were analysed. The results showed that the LUEVT of 25 % and 45 % SiCp/Al composites were reduced by 39.3 % and 30.7 % respectively compared to the CT cutting forces. The experiments verified the consistency of the surface roughness and chip morphology with the finite element simulation results. The stability of the cutting force during the cutting process is also improved, as the material removal process mainly takes the form of small particle fragmentation and matrix encapsulation.

Cutting Force Model of SiCp/Al Composites in Ultrasonic Elliptical Vibration Assisted Cutting with Negative Rake Angle

Cutting Force Model of SiCp/Al Composites in Ultrasonic Elliptical Vibration Assisted Cutting with Negative Rake Angle

Removal mechanism and hole quality of SiCp/Al composites by ultrasonic elliptical vibration-assisted helical milling

SiCp/Al composites are widely used in the aerospace field due to their excellent properties. However, the huge difference in the properties of silicon carbide and aluminum matrix materials can easily lead to machining defects. Ultrasonic vibration-assisted machining is an effective method to deal with difficult-to-machine materials. In this study, ultrasonic elliptical vibration is applied to the helical milling of SiCp/Al composites. Firstly, the ultrasonic elliptical vibration-assisted helical milling (UEVHM) cutting-edge trajectory is modeled, and the equation of the UEVHM tool-chip separation condition is established, which lays a foundation for the analysis of the cutting mechanism. Then, the influence of ultrasonic elliptical vibration on the removal mechanism of SiCp/Al composites was investigated by finite element simulation. It was found that UEVHM can reduce the tearing of aluminum matrix and reduce the hole damage by changing the direction of the cutting velocity and the relative position of the cutting edge and particles. Finally, the single-factor experiment was carried out, and the surface morphology and roughness of HM and UEVHM were compared. The influence of process parameters on the surface roughness of UEVHM was analyzed. The experimental results show that compared with HM, UEVHM can reduce surface defects and exit damage, to obtain better surface roughness and exit edge quality. The increase in cutting speed can reduce the roughness, and the increase in pitch and revolution speed will increase the surface roughness.

Investigation on machinability of SiCp/Al composites under the synergistic effect of pulsed laser assisted and ultrasonic elliptical vibration cutting

While SiCp/Al composites are widely used in engineering applications owing to their excellent material properties, the traditional machining of SiCp/Al composites remains challenging, mainly in terms of poor surface quality and severe tool wear. In this study, a multi-energy field assisted cutting method—pulsed laser-assisted ultrasonic elliptical vibration cutting (PLA-UEVC)—for precision and high-efficiency machining of SiCp/Al composites is introduced. In this method, the intermittent impact cutting effect caused by the tool's ultrasonic frequency elliptical vibration, pulsed-laser-induced material-generated thermoelastic excitation effect, and transient temperature field synergistically work together to enhance the machinability of SiCp/Al composites. Temperature-field simulations were first utilized to simulate the temperature under suitable pulsed laser parameters. Comparative experiments with different volume fractions and particle sizes under different machining methods were conducted to evaluate the advantages of the proposed composite energy field-assisted machining method in terms of chip modulation, surface quality improvement, and tool performance improvement. The experimental results show that multi-energy field assisted cutting achieves better chip control and obtains shorter, easier-to-break chips than traditional cutting, pulsed laser-assisted cutting, and ultrasonic vibration-assisted cutting. The cutting forces of the three industrial-grade SiCp/Al6061 composites with different material properties were significantly reduced (by more than 55 %), with a surface roughness of less than 30 nm obtained for all three composites, effectively suppressing surface defects such as particle failure, thermal damage, and residual height caused by tool vibration. In addition, multi-energy field assisted cutting effectively minimized the abrasive and diffusive wear of the tool and reduced the adhesion phenomenon on the back face of the tool. These findings provide an important theoretical basis and practical machining guidance for multi-energy-field synergistic machining to improve the machinability of SiCp/Al composites.

Research on the surface morphology of titanium alloy ultrasonic elliptical vibration cutting considering flank extrusion and material rebound

Research on the surface morphology of titanium alloy ultrasonic elliptical vibration cutting considering flank extrusion and material rebound

An Experiment Study on Surface Topography of GH4169 Assisted by Ultrasonic Elliptical Vibration Ultra-Precision Turning

Nickel-based superalloys (GH4169) are a typical difficult-to-machine material with poor thermal conductivity and severe work hardening. They are also prone to poor surface quality, severe tool wear, and poor machinability, which affect their performance. In this paper, an experimental study of GH4169 ultrasonic elliptical vibratory ultra-precision cutting was carried out. The experimental results show that ultrasonic elliptical vibratory cutting (UEVC) significantly reduces surface roughness and improves surface quality compared to conventional cutting (CC). The effects of cutting parameters such as cutting speed, feed rate, cutting depth, ultrasonic amplitude, and tool nose radius on the surface roughness of GH4169 workpieces were further investigated in UEVC. Based on the analysis of the experimental data, the optimal combination of parameters for GH4169 ultrasonic elliptical vibration ultra-precision cutting was determined: cutting speed of 3 m/min, feed rate of 16 μm/rev, cutting depth of 2 μm, ultrasonic amplitude of Ay = 3.0 μm, Az = 0.8 μm, and a tool nose radius of 0.8 mm. This parameter combination improves the machining quality of GH4169 and provides a valuable reference for the subsequent development of ultrasonic elliptical vibratory cutting for other difficult-to-machine materials.

Machinability of elliptical ultrasonic vibration milling γ-TiAl: Chip formation, edge breakage, and subsurface layer deformation

Superior strength and high-temperature performance make γ-TiAl vital for lightweight aero-engines. However, its inherent brittleness poses machining problems. This study employed Elliptical Ultrasonic Vibration Milling (EUVM) to address these problems. Considering the influence of machining parameters on vibration patterns of EUVM, a separation time model was established to analyze the vibration evolutionary process, thereby instructing the cutting mechanism. On this basis, deep discussions regarding chip formation, cutting force, edge breakage, and subsurface layer deformation were conducted for EUVM and Conventional Milling (CM). Chip morphology showed the chip formation was rooted in the periodic brittle fracture. Local dimples proved that the thermal effect of high-speed cutting improved the plasticity of γ-TiAl. EUVM achieved a maximum 18.17% reduction in cutting force compared with CM. The force variation mechanism differed with changes in the cutting speed or the vibration amplitude, and its correlation with thermal softening, strain hardening, and vibratory cutting effects was analyzed. EUVM attained desirable edge breakage by achieving smaller fracture lengths. The fracture mechanisms of different phases were distinct, causing a surge in edge fracture size of γ-TiAl under microstructural differences. In terms of subsurface deformation, EUVM also showed strengthening effects. Noteworthy, the lamellar deformation patterns under the cutting removal state differed from the quasi-static, which was categorized by the orientation angles. Additionally, the electron backscattering diffraction provided details of the influence of microstructural difference on the orientation and the deformation of grains in the subsurface layer. The results demonstrate that EUVM is a promising machining method for γ-TiAl and guide further research and development of EUVM γ-TiAl.

Evolution mechanism of microstructure and microhardness of Ti–6Al–4V alloy during ultrasonic elliptical vibration assisted ultra-precise cutting

The ultra-precision Ti–6Al–4V alloy parts are growing used in medical and aerospace industries, and which always work in the extreme working conditions such as high temperature, high pressure, and variable load. Thus, the requirements for machining accuracy and surface quality of parts are getting higher and higher. The ultrasonic elliptical vibration assisted cutting (UEVC) technology has been proved to be an effective method for the ultra-precision machining of Ti–6Al–4V alloy. However, in the UEVC process, the evolution mechanism of microstructure and microhardness, which directly affect the service performance and life, is unrevealed. In this paper, the comprehensive investigations of microstructural plastic deformation, grain refinement, phase transformation and microhardness of machined surface layer under conventional cutting (CC) and UEVC processes are carried out. The experimental results indicated that, due to the effects of UEVC technology, the plastic deformation area show obvious compression deformation, the depth of plastic deformation is less than 10 μm, there is no obvious phase transformation on the machined surface layer material, and the hardening rate of machined surface is more than 20%. These findings show the UEVC technology has a unique influence on the microstructure and microhardness of Ti–6Al–4V alloy, which have important implications for the cutting parameter design of ultra-precision Ti–6Al–4V alloy parts.

Ultrasonic elliptical vibration micro-cutting mechanism of CoCrFeNiAlX short fiber reinforced aluminum-based composite

This study explores the precision micro-machining of CoCrFeNiAlX short fiber-reinforced 7A09 aluminum matrix composites, focusing on the interplay between machining parameters and composite properties. The investigation scrutinizes the influence of vibrational amplitude, oscillation frequency, penetration depth, fiber orientation, and aluminum concentration on machining dynamics. Findings reveal that enhancing the X-axis vibrational amplitude to 80 μm is associated with a decrease in machining force, which then rises after reaching a threshold. In contrast, maintaining the Y-axis amplitude below 90 μm significantly increases the machining force. Higher amplitudes and frequencies were observed to reduce machining forces by up to 57% at an ultrasonic frequency of 15 kHz. Employing ultrasonically assisted vibration cutting (UEVC) culminated in a substantial 72% decrease in machining forces when fibers were optimally oriented at 45°. The study also identifies a direct correlation between the cutting temperature and both the vibrational amplitude and penetration depth, with the Y-axis amplitude having a more significant impact, causing a 55% variation in temperature. An increase in frequency initially lowers the cutting temperature, with the lowest temperature of 92 °C achieved at 5 kHz, while the peak temperature occurs at a machining depth of 60 μm. Temperature profiles indicate an initial rise with increased fiber orientation, followed by a decline. A slight increase in aluminum concentration marginally raises the cutting temperature. Furthermore, UEVC is found to produce a parabolic residual stress distribution, where amplitude and penetration depth determine the peak stress levels, and higher frequencies contribute to stress reduction. Fiber orientation also affects residual stress, with proper alignment reducing compressive stress and misalignment increasing it. The lowest point of residual compressive stress is detected in the Al0.6 fiber composite, while the peak is observed in the Al1 composites.

Research on tool wear and surface quality in laser-assisted ultrasonic elliptical vibration cutting of cemented carbide

The Laser-ultrasonic elliptical vibration cutting (LA-UEVC) method was introduced for machining challenging cemented carbide. The machining parameters were estimated through numerical simulation, and the cutting forces, the tool wear and the workpiece surface quality were analyzed and investigated. Compared to precision cutting, during LA-UEVC of cemented carbide, the main cutting force and the cutting radial thrust force were reduced by 44.3% and 31.2%, respectively. Moreover, the tool wear decreased, which led to an increase in tool life by 118.8%, and a maximum reduction of 89.7% of Workpiece surface roughness was received. The impact of laser power and cutting parameters on surface roughness was analyzed through orthogonal experiments, and a surface roughness prediction model was established using a quadratic regression model.

Generation mechanism of the surface morphology on tilted ultrasonic elliptical vibration cutting TC4 titanium alloy

TC4 titanium alloy is utilized in aerospace and a wide range of other applications due to its high strength and corrosion resistance, but its poor thermal conductivity and high ductility introduce challenges in machining. In this paper, firstly, a mathematical model of workpiece surface morphology under tilted ultrasonic elliptical vibration cutting (TUEVC) was established based on the tip trajectory and material removal mechanism, and the variation of workpiece surface morphology was investigated at different tool tilt angles θ, and it was found that the tilt θ in a certain range could significantly reduce the surface residual height compared with that of ordinary ultrasonic elliptical vibration cutting (UEVC). Second, the TUEVC experiment of TC4 titanium alloy was carried out to comparatively analyze the changes in the surface morphology, surface profile, and surface roughness of the workpiece under different tilt θ, the effect of each machining parameter (cutting speed, feed, and ultrasonic amplitude) on surface roughness was explored. The experimental results indicate that as the tilt θ changes from 0° to 90° throughout the process, the workpiece surface morphology flatness decreases and then increases. When the tilt angle θ is 45°, workpiece cutting surface roughness is minimized (Sa = 0.157), compared with the ordinary ultrasonic elliptical vibration cutting roughness is reduced by 47.6 % maximum. Both the surface morphology flatness and the surface roughness of the workpiece are at their smallest, whereas the theoretical profile curve and cutting surface profile curve are at their most consistent. Under the same machining parameters, TUEVC can reduce the surface roughness more effectively compared with UEVC, this technique reduces surface roughness by 16 %, 23 %, and 26 % at maximum for different cutting speeds, feeds, and ultrasonic amplitudes, respectively.

Observation of chip-producing behavior in ultraprecision diamond cutting of additively manufactured Alloy 718 utilizing ultrasonic elliptical vibration

Observation of chip-producing behavior in ultraprecision diamond cutting of additively manufactured Alloy 718 utilizing ultrasonic elliptical vibration

Design, modeling and experiment of a novel ultrasonic elliptical vibration generator

Design, modeling and experiment of a novel ultrasonic elliptical vibration generator

Experimental Study on the Roundness of Deep Holes in 7075 Aluminum Alloy Parts by Two-Dimensional Ultrasonic Elliptical Vibration Boring.

The 7075 aluminum alloy deep hole pipe finds extensive applications in the aerospace industry due to its remarkable attributes, such as high strength, exceptional wear resistance, and favorable mechanical properties. However, traditional boring processes for 7075 aluminum alloy deep hole pipes tend to generate elevated cutting forces, potentially leading to deformation issues in these deep holes. In response to these challenges, this study introduces a novel approach involving the use of a two-dimensional ultrasonic elliptical vibration tool. This tool features a single excitation asymmetric structure and aims to enhance the deep hole machining process in 7075 aluminum alloy. The research methodology involved several key steps. First, theoretical analysis and simulation were performed to study the motion trajectory of the cutting edge of the tool. Second, practical experiments were conducted comparing two-dimensional ultrasonic elliptical vibration boring with conventional boring for 7075 aluminum alloy deep hole pipes. The results demonstrate that, in contrast to conventional boring, two-dimensional ultrasonic vibration boring could achieve a maximum reduction of 54.1% and an average reduction of 50.4% in the roundness value of the deep holes. The impact of machining parameters on deep hole roundness is assessed through experimental analysis, leading to the determination of optimal processing parameters. In summary, this experimental research has a certain reference significance for the application of 7075 aluminum alloy deep hole parts in the aerospace field.

Undeformed chip thickness with composite ultrasonic vibration-assisted face grinding of silicon carbide: Modeling, computation and analysis

In order to achieve high efficiency and low damage processing of hard and brittle materials, composite ultrasonic vibration-assisted face grinding (CUVAFG) has been proposed by comprehensively combining the high efficiency of axial ultrasonic vibration grinding (UVAG) and the low damage of elliptic ultrasonic vibration grinding (EVAG). However, the three-dimensional ultrasonic vibration brings about a more complicated machining mechanism than the previous ultrasonic vibration-assisted grinding methodology. Hence, in order to explore the grinding mechanism in deep, this paper first developed a new model of undeformed chip thickness for CUVAFG from the perspectives of the kinematic mechanism and elastic-plastic deformation mechanism. Then the influences of different processing parameters on interference rate and undeformed chip thickness were further confirmed. Finally, CUVAFG experiments of silicon carbide (SiC) ceramics were conducted to study the relationship between the undeformed chip thickness and the resultant grinding forces, specific grinding energy, ground surface morphology and roughness, and subsurface damage. It is found from the experimental results that the critical chip thickness of brittle-ductile transition in CUVAFG is between 0.31 and 0.35 μm. As the undeformed chip thickness is less than the critical value, the grinding forces and the specific grinding energy increases with the undeformed chip thickness, but the ground surface roughness decreases with improved surface morphology and shallow subsurface damage. After exceeding the critical value, the grinding force remains unchanged, the specific grinding energy decreases, and ground surface roughness increases with deteriorated surface morphology and deepened subsurface damage. For the purpose of good machining surface integrity, it is essential to guarantee that the undeformed chip thickness is less than the critical value. The computational and experimental results have demonstrated the contribution of the developed undeformed chip thickness model to understanding the grinding performance of hard and brittle material by CUVAFG.