Ultrasonic Vibration-assisted Machining Research Articles

Multiscale simulation and experimental study on ultrasonic vibration assisted machining of SiCp/Al composites considering acoustic softening

Ultrasonic vibration assisted machining (UVAM) is an attractive option to achieve high-quality and low-wear machining of the advanced composites. The scope of this paper is to evaluate the role of ultrasonic vibration on the microstructure and material removal mechanism for SiCp/Al composites. Firstly, an ultrasonic vibration assisted tension (UVAT) molecular dynamics (MD) simulation method for SiCp/Al composites is proposed. The simulation results verify the existence of acoustic softening effect for SiCp/Al composites under ultrasonic vibration loads. Furthermore, it is found that the acoustic softening originates from the dynamic evolution of the dislocations in the Al matrix. However, the acoustic softening is hardly mentioned in conventional finite element (FE) simulations depicting the microscopic removal mechanism of materials. In this paper, the constitutive correction method is adopted to realize it. The stress reduction of the Al matrix caused by acoustic softening is reverse-identified, and the maximum is 102 MPa. Finally, a novel FE model for UVAM of SiCp/Al composites considering acoustic softening is constructed, and the microscopic removal mechanism of SiCp/Al composites is revealed by the FE simulation and microscopic experimental results. On the one hand, the ultrasonic vibration enhances the stress relaxation of the Al matrix by reducing the dislocation density, and further enhances the deformation ability of SiCp/Al composites. On the other hand, the matrix tearing dominates the generation and propagation of shear band cracks in conventional machining (CM), while the dominant factor in UVAM is the finely broken SiC particles inside the shear band. This study enhances the understanding of the microscopic removal mechanism in UVAM for SiCp/Al composites.

Insights into vibration-induced softening effect: A thermodynamic approach

This work investigates the wear behavior of nickel-based alloy during ultrasonic vibration-assisted machining (UVAM) by combining molecular dynamics simulation and thermodynamic theory. The research reveals that the tangential force exhibits periodic variations during UVAM, with a period half of the vibration period. Tangential force and total resistance decrease due to the synergistic effect of vibration-induced softening and thermal softening. A deeper understanding of the total resistance variation during the UVAM process can be achieved by the dimensionless resistance coefficient, which is difficult for the traditional friction coefficient (CoF). The Bejan number elucidates the contributions of the thermal softening and vibration-induced softening effects in the wear process. The findings highlight that the vibration-induced softening effect dominates when adjusting the amplitude for the active control of friction. In contrast, when the frequency is modulated, the contributions of vibration-induced softening and thermal softening effects are nearly equivalent. Furthermore, the wear mode transitions with increasing vibration frequency, characterized by the Strouhal number (Srw). The vibration wear mode attains dominance when Srw > 1.88. This work provides essential theoretical guidance to gain insight into the wear behavior in UVAM to optimize the machining performance.

Material removal and damage formation mechanisms induced by periodic indentation during ultrasonic vibration-assisted scratching of SiCf/SiC composites

Fiber-reinforced ceramic matrix composites (CMCs) exhibit high hardness, brittleness, heterogeneity, and anisotropy. This study explores the material removal and damage formation mechanisms during ultrasonic vibration-assisted scratching of SiCf/SiC composites through experimental and micro-finite element simulations. The research reveals that high-frequency periodic indentation-separation of abrasive grain influences stress transfer and crack propagation, which are affected by the interfacial layer and fiber orientation. Crack deflection plays a crucial role in material removal and determines the amplitude of normal scratching force. Stress transfer interference primarily governs damage formation, with more severe damage occurring along the longitudinal and transverse fiber directions due to secondary stress concentration and crack deflection. In contrast, scratching along the perpendicular fiber direction requires higher normal forces due to residual adjacent phase materials, but results in more controlled material removal and less damage. The study provides insights into optimizing the ultrasonic vibration-assisted machining of CMCs to minimize damage.

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.

Unveiling damage mechanisms of SiC fiber-reinforced titanium matrix composites through ultrasonic scratching

SiCf/Ti composites are increasingly being utilized in the aerospace field due to their excellent performance. However, during the application of this material, issues such as fiber fracture and debonding often occur during processing. Ultrasonic vibration-assisted machining technology avoids the waste of cutting fluid and its environmental impact in traditional production, making it widely used in the ultra-precision and environmentally friendly processing of composite materials. This study explores the damage formation mechanism during material removal using diamond scratching. A comparison was made between the specific energy and morphology of ultrasonic scratching and conventional scratching, and a model for fiber fracture depth was established. The results indicate that conventional cutting leads to fiber bending and crushing, with bent fibers causing deformation to the matrix, which further affects the fibers behind. EBSD results confirm that fiber bending deformation affects the microstructure changes in the matrix. Under ultrasonic scratching, scratching force and specific energy decreased by 25% and 50%, respectively, compared to conventional scratching. This effectively reduces the deformation of fibers on the matrix during cutting and enhances the tool's ability to shear and remove fibers. CT analysis of the subsurface showed that under ultrasonic scratching, the maximum decrease in fiber fracture depth was 13% compared to traditional methods. This study guides the clean and low-damage machining of SiCf/Ti composites.

Effect of ultrasonic amplitude and riveting speed on mechanical properties of Ti-45Nb riveted lap joints

Ultrasonic vibration-assisted machining has been introduced as a new process in riveting aircraft components. In this paper, the effects of different ultrasonic amplitudes and riveting speeds on the quality, shear properties, and cross-tension properties of riveted joints are investigated. The failure sample fracture was characterized using a scanning electron microscope and the cause of the fracture was discussed. The results show that the ultrasonic amplitude is negatively correlated with the height of the riveted joint and positively correlated with the diameter of the riveted joint. The maximum shear failure load was obtained at a riveting speed of 5 mm/s with an ultrasonic amplitude of 35.3 μm, and the maximum cross tensile failure load was obtained at an ultrasonic amplitude of 23.3 μm. All shear fractures occurred in the rivet shanks and all cross fractures occurred in the rivet manufactured head, and the failure modes of both shear and cross-tension fracture were mixed brittle and plastic fracture modes.

Effects of ultrasonic vibration-assisted machining methods on the surface polishing of silicon carbide

Effects of ultrasonic vibration-assisted machining methods on the surface polishing of silicon carbide

Enhancing machining efficiency of Ti-6Al-4V through multi-axial ultrasonic vibration-assisted machining and hybrid nanofluid minimum quantity lubrication

Ti-6Al-4V offers a balance of good strength with lightweight properties. Yet, Ti-6Al-4V poses machining challenges, including low thermal conductivity, chemical adhesion to cutting tools, and chip removal difficulties. To improve machining efficiency, Ultrasonic Vibration-Assisted Machining (UVAM) has emerged as a promising approach. UVAM has demonstrated reduced tool wear, cutting forces, and improved surface quality compared to Conventional Machining (CM). Additionally, Minimum Quantity Lubrication (MQL) methods offer sustainable coolant alternatives, with recent research focusing on Nanofluid-MQL (NMQL) and Hybrid Nanofluid-MQL (HNMQL) for enhanced performance. Although there exists a body of literature showcasing the promising effects of UVAM and MQL methods individually, comprehensive investigations into the synergistic effects of these methodologies remain limited. This study addresses these critical research gaps by conducting a systematic examination of combined application of multi-axial UVAM and HNMQL. Specifically, it delves into the comparison of different vibration directions within UVAM, evaluates the effectiveness of UVAM when combined with cutting fluids incorporating Al2O3 and CuO nanoparticles in NMQLs and HNMQLs, and contrasts these novel approaches with conventional machining methods. The study unfolds in three distinct stages. The first stage examines the ultrasonic cutting mechanism and its combined application with the MQL technique. In the second stage, the study investigates the physical properties of the cutting fluids, including contact angle and surface tension. The final stage encompasses slot milling operations, where an array of parameters such as cutting forces, surface roughness, surface topography, surface texture, and the occurrence of burr formations are rigorously analyzed. The results demonstrate that the combination of multi-axial UVAM with HNMQL yields substantial advantages over traditional machining methods. Notably, it leads to a remarkable reduction in cutting forces (up to 37.6 %) and surface roughness (up to 37.4 %). Additionally, this combination engenders the production of highly homogeneous and uniform surface textures, characterized by minimal surface defects and a significantly diminished occurrence of burr formations. These findings underscore the potential of multi-axial UVAM combined with HNMQL as a promising approach in enhancing the machining of Ti-6Al-4V, thus offering a pathway to enhance the efficiency and precision of aerospace component manufacturing processes.

Investigation of the Combined Effects of Ultrasonic Vibration-Assisted Machining and Minimum Quantity Lubrication on Al7075-T6

The aluminum alloy Al7075-T6 finds extensive application in the aviation and automotive industries, where machining plays a pivotal role. Emerging techniques such as Ultrasonic Vibration-Assisted Machining (UVAM) and Minimum Quantity Lubrication (MQL) hold promise for enhancing machining efficiency. In this study, the combined use of UVAM and MQL for slot milling of Al7075-T6 was investigated. The results demonstrate that UVAM reduced cutting forces by an average of 10.87% in MQL and 8.31% in Conventional Cutting Fluid (CCF) conditions when compared to Conventional Machining (CM). In addition, UVAM yielded significantly improved surface finishes, characterized by an average reduction in surface roughness of 41.86% in MQL and 32.11% in CCF conditions relative to CM. Furthermore, surfaces subjected to UVAM exhibited fewer instances of burn marks and tool-induced markings, reduced chip splashing, and more uniform surface integrity compared to those manufactured with CM. Lastly, chips generated through UVAM exhibited distinct characteristics, notably shorter length, curvier shape, and a distinctive half-turn morphology when compared with the irregular chips produced through CM. In conclusion, our findings underscore the potential of UVAM in synergy with MQL to augment the machining of Al7075-T6 alloy, thereby yielding superior-quality machined components with enhanced operational efficiency.

Feasibility and mechanism of atmospheric pressure cold plasma jet (APCPJ) assisted micro-milling of bulk metallic glasses (BMGs)

The unique microstructures of bulk metallic glasses (BMGs) provide them with excellent mechanical, physical, and chemical properties, having important applications in the fields of medical devices, military equipment, aerospace, etc. However, the superb mechanical properties also contribute to poor machinability of the BMGs. Currently, researchers have proposed to improve the machinability by single-point diamond turning, laser-assisted machining and ultrasonic vibration-assisted machining, but their plasticity and viscous flow remain unchanged, thus restraining further enhancement of surface quality. Atmospheric pressure cold plasma jet (APCPJ), which is rich in active particles, can effectively ameliorate material machinability by modulating material properties. In this paper, we propose to use the APCPJ to regulate the properties of BMGs, and carry out nanoindentation, nanoscratching, and micro-milling experiments to investigate the influence mechanisms of APCPJ on the material properties and cutting process. The results demonstrate that after modified by APCPJ, plastic deformability of the BMGs is improved due to the increase of free volume content; meanwhile, the viscous flow is inhibited. The micro-milling experiments indicate that under the conditions of feed rate Vf = 500 μm/s, spindle speed n = 30,000 rpm, and cutting depth ap = 5 μm, the improvement effect of APCPJ on the cutting process is relatively optimum. The surface roughness Ra of the Zr-based BMG and Ti-based BMG obtained by APCPJ are respectively 0.076 μm and 0.081 μm, which can be reduced by 37.7 % and 38.2 % compared with dry micro-milling. The cutting forces Fz in the direction of cutting depth are also reduced by 30.9 % and 23.3 %, respectively. The APCPJ-assisted micro-milling method proposed in this work may ameliorate the machining quality of BMGs and promote the application of BMGs and APCPJ-assisted machining technology in aerospace and precision machining.

Effect of Duty Cycle on Cutting Force for Ultrasonic Vibration-Assisted Milling Carbon Fiber-Reinforced Polymer Laminates

Cutting force is an important factor that affects the surface quality of machining carbon fiber-reinforced polymer (CFRP). High cutting force can lead to surface damage such as the burrs and the delamination in the machining process of CFRP. Ultrasonic vibration-assisted machining (UVAM) can reduce the cutting force in the machining process. This work is focused on the relationship between the duty cycle and the cutting force in UVAM of CFRP. Based on the kinematics of UVAM, the movement of the cutting tool edge and the tool–workpiece separation in UVAM were analyzed, and a calculation formula for the duty cycle was obtained. The milling experiment of CFRP was conducted to compare the cutting force between UVAM and conventional machining (CM), and the relationship between the reduction in the cutting force in UVAM and the duty cycle was determined. The experimental results showed that when the duty cycle was 0.2916, the cutting force of UVAM was reduced by 7.4% to 27% compared with that of CM. When the duty cycle was 1, the cutting force of UVAM was reduced by −4.5% to 7.5% compared with that of CM. Therefore, the effect of reducing the cutting force of UVAM can be enhanced by adjusting the process parameters to reduce the duty cycle of UVAM, and a lower cutting force can be obtained.

An Experimental Study on Ultrasonic Vibration-Assisted Turning of Aluminum Alloy 6061 with Vegetable Oil-Based Nanofluid Minimum Quantity Lubrication

Minimum quantity lubrication (MQL) is a potential technology for reducing the consumption of cutting fluids in machining processes. However, there is a need for further improvement in its lubrication and cooling properties. Nanofluid MQL (NMQL) and ultrasonic vibration-assisted machining are both effective methods of enhancing MQL. To achieve an optimal result, this work presents a new method of combining nanofluid MQL with ultrasonic vibration assistance in a turning process. Comparative experimental studies were conducted for two types of turning processes of aluminum alloy 6061, including conventional turning (CT) and ultrasonic vibration-assisted turning (UVAT). For each turning process, five types of lubricating methods were applied, including dry, MQL, nanofluid MQL with graphene nanosheets (GN-MQL), nanofluid MQL with diamond nanoparticles (DN-MQL), and nanofluid MQL with a diamond/graphene hybrid (GN+DN-MQL). A specific cutting energy and areal surface roughness were adopted to evaluate the machinability. The results show that the new method can further improve the machining performance by reducing the specific cutting energy and areal surface roughness, compared with the NMQL turning process and UVAT process. The diamond nanoparticles are easy to embed on the workpiece surface under the UVAT process, which can increase the specific cutting energy and Sa as compared to the MQL method. The graphene nanosheets can produce the interlayer shear effect and be squeezed into the workpiece, thus reducing the specific cutting energy. The results provide a new way for the development of eco-friendly machining.

Surface fractures in pre-crystallized and crystallized zirconia-containing lithium silicate glass-ceramics generated in ultrasonic vibration-assisted machining

Machining-induced surface fractures in ceramic restorations is a long-standing problem in dentistry, affecting the restorations’ functionality and reliability. This study approached a novel ultrasonic vibration-assisted machining technique to zirconia-containing lithium silicate glass-ceramics (ZLS) and characterized its induced surface fracture topographies and morphologies to understand the microstructure-property-processing relations. The materials were processed using a digitally controlled ultrasonic milling machine at a harmonic vibration frequency with different amplitudes. Machining-induced surface fracture topographies were measured with a 3D white light optical profilometer using the arithmetic mean, peak and valley, and maximum heights, as well as the kurtosis and skewness height distributions, and the texture aspect ratios. Fracture morphologies were analysed using scanning electron microscopy (SEM). The surface fracture topographies were significantly dependent on the material microstructure, the mechanical properties, and the ultrasonic machining vibration amplitudes. Larger scale fractures with higher arithmetic mean, peak and valley heights, and kurtosis and skewness height distributions were induced in higher brittleness indexed pre-crystallized ZLS than lower indexed crystallized ZLS by conventional machining. Conchoidal fractures occurred in pre-crystallized ZLS while microcracks were found in crystallized state although brittle fractures mixed with localized ductile flow deformations dominated all machined ZLS surfaces. Ultrasonic machining at an ideal vibration amplitude resulted in more ductile removal, reducing fractured-induced peaks and valleys for both materials than conventional processing. This research demonstrates the microstructure-property-processing interdependence for ZLS materials and the novel machining technique to be superior to current processing, reducing fractures in the materials and potentially advancing dental CAD/CAM techniques.

Experimental Research of High-Quality Drilling Based on Ultrasonic Vibration-Assisted Machining.

Micro-hole is widely used in various fields, and common machining methods of micro-hole in factories are drilling and electrical discharge machining (EDM), but because of low machining efficiency, these methods cannot meet requirements. Therefore, it is urgent to investigate a high efficient micro-hole machining technology to meet the demands of micro-hole machining in factory. Over past few decades, ultrasonic machining technology has developed rapidly and achieved good results in solving many critical machining problems in field of difficult-to-cut materials. Therefore, this paper builds an ultrasonic vibration-assisted drilling (UAD) experiments platform to combine micro-fine small hole drilling with ultrasonic machining technology for micro-hole multi-factor experimental research. Results show that UAD machining of micro-hole below diameter 0.5 mm is comparable to conventional drilling machining because of its high-frequency pulse intermittent cutting process, stable change in machining diameter, good stability of parameters such as shape tolerance roundness and cylindricity, small cutting force during cutting, small tool wear, and small surface roughness of inner wall of micro-hole. Compared with EDM, UAD has high efficiency and good stability of parameters such as diameter and roundness of shape tolerance. Comprehensive analysis of UAD can be used as an alternative technology solution for machining small holes in non-special requirements of metal materials in factory and has technical feasibility of stable batch production.

The effects of scratching speed in ultrasonic vibration-assisted single diamond scratching process

Ultrasonic vibration-assisted machining has been widely used in manufacturing hard and brittle materials. Previous studies have shown that the vertical ultrasonic vibration in ultrasound-assisted single diamond scratching can affect the scratching forces, surface quality, and material removal mechanism by two mechanisms: changing the contact mode between the single diamond and the workpiece and increasing the speed of the single diamond relative to the workpiece. However, some studies point out that increasing the speed has little effect on the scratching force and material removal mechanism. Therefore, it is necessary to conduct an investigation that takes into account the effects of both scratching velocity and ultrasonic vibration on scratching force, surface quality, and material removal mechanisms. In this study, the single diamond conventional scratching (CS) and ultrasonic vibration-assisted scratching (UAS) experiments have been conducted at different scratching speeds to investigate the material removal mechanism of ultrasonic vibration-assisted machining. The effects of increasing the scratching speed on cutting forces, material removal mechanism, and machined surface quality are investigated. The results show that in both CS and UAS processes with low to medium scratching speeds (less than1000 mm/s), increasing the scratching speed leads to more brittle material removal and lower surface quality. At the same time, the scratching speed has almost no effect on the scratching speed force.

Edge chipping damage in lithium silicate glass-ceramics induced by conventional and ultrasonic vibration-assisted diamond machining.

Diamond machining of lithium silicate glass-ceramics (LS) induces extensive edge chipping damage, detrimentally affecting LS restoration functionality and long-term performance. This study approached novel ultrasonic vibration-assisted machining of pre-crystallized and crystallized LS materials to investigate induced edge chipping damage in comparison with conventional machining. The vibration-assisted diamond machining was conducted using a five-axis ultrasonic high-speed grinding/machining machine at different vibration amplitudes while conventional machining was performed using the same machine without vibration assistance. LS microstructural characterization and phase development were performed using scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques. Machining-induced edge chipping depths, areas and morphology were also characterized using the SEM and Java-based imaging software. All machining-induced edge chipping damages resulted from brittle fractures. The damage scales, however, depended on the material microstructures; mechanical properties associated with the fracture toughness, critical strain energy release rates, brittleness indices, and machinability indices; and ultrasonic vibration amplitudes. Pre-crystallized LS with more glass matrix and lithium metasilicate crystals yielded respective 1.8 and 1.6 times greater damage depths and specific damage areas than crystallized LS with less glass matrix and tri-crystal phases in conventional machining. Ultrasonic machining at optimized amplitudes diminished such damages by over 50 % in pre-crystallized LS and up to 13 % in crystallized LS. This research highlights that ultrasonic vibration assistance at optimized conditions may advance current dental CAD/CAM machining techniques by significant suppression of edge chipping damage in pre-crystallized LS.

Investigation of force modeling in ultrasonic vibration-assisted drilling SiCf/SiC ceramic matrix composites

Due to their exceptional high-temperature and rust resilience, SiCf/SiC ceramic matrix composites have been regarded as potential high-temperature components. For application, to overcome issues resulting from the high hardness and brittleness, the ultrasonic vibration-assisted machining technique is primarily adopted in the machining of SiCf/SiC ceramic matrix composites. It is essential to develop a force model for a better understanding of the material removal and cutting processes by applying ultrasonic vibration. As a result, studies on force modeling during ultrasonic vibration-assisted drilling of SiCf/SiC ceramic matrix composites have been conducted in this study, taking into account the trajectory of the drilling tool, the tool-workpiece contact state, and the material removal mode. Based on the coefficient calibration experiment and least square method, the irregular coefficient of abrasive grains, the crack growth parameters of materials, and the mechanical parameters that are difficult to be measured were determined. After that, the drilling parameters and vibration parameters were merged to build the analytical force model, and the parameter influence rules on the force was also studied. The suggested drilling force model concurred well with tests under the highest relative error of 17.34 %, according to the findings of the confirmation experiments.

Study on force-thermal characteristics and cutting performance of titanium alloy milled by ultrasonic vibration and minimum quantity lubrication

Ti-6Al-4V alloys are widely utilized in aerospace field because of its excellent physical and mechanical performance. Nevertheless, titanium alloy has high strength and low thermal conductivity, which leads to poor processability. Therefore, in the titanium alloys cutting processing, decreasing cutting force and cutting temperature are reliable ways to improve its cutting machinability. The high-frequency intermittent cutting effect of ultrasonic vibration be beneficial to reduce the milling force, and the minimum quantity lubrication (MQL) technology can efficiently improve the friction environment and decrease the cutting temperature. Combined with the technological superiority of ultrasonic vibration assisted machining (UVAM) and MQL, this paper proposes to use UVAM&MQL technology for titanium alloy milling. Firstly, theoretical analysis shows that the separation property of UVAM can enhance the cooling/lubrication of MQL, and the coupling action of UVAM and MQL can improve the force and temperature generated in the cutting process. Then, the variation of surface roughness, surface morphology and chip morphology under this force-thermal coupling is discussed through milling experiments, and compared with conventional milling (CM) and UVAM. From the results, we make out that compared with CM, both UVAM and UVAM&MQL can reduce the cutting force. When the cutting speed is high, UVAM can't reduce the cutting temperature, while UVAM&MQL produces a smaller cutting temperature under all parameters. When the UVAM&MQL method is adopted for processing, the surface is smoother, and the surface forms a clear and uniform vibration texture. Compared with CM and UVAM, the surface roughness of UVAM&MQL is decreased by about 27–51 % and 5–44 %, respectively. In addition, UVAM&MQL method is beneficial to promote the transformation of serrated chip to non-serrated chip.

State-of-the-art hybrid-assisted machining processes of nickel-based superalloys

Nickel-based superalloys are most commonly used in aerospace and marine applications owing to their superior mechanical properties. They show great resistance against creep and stress rupture at high temperatures. However, they are considered difficult to machine by conventional machining (CM) techniques owing to their low thermal conductivity, work hardening ability, presence of hard carbide particles, and chemical affinity toward various tool materials. Hybrid-assisted machining techniques can be an alternative to CM to improve the machinability of these alloys. Therefore, the present article discusses the effect of heat-assisted machining techniques like laser-assisted machining (LAM), flame-assisted machining (FAM), plasma-assisted machining (PAM), and induction-assisted machining (IAM) of Ni-based superalloys compared to CM. Additionally, cryogenic machining, ultrasonic vibration-assisted machining (VAM), and a combination of hybrid-assisted machining techniques on the machinability of Ni-based superalloys have also been discussed.

Oscillations of Cutting Tool as a Useful Effect in Turning and Drillingm

The paper presents the fixtures with movably mounted turning and drilling cutting tools. The fixtures were developed on the principle of oscillating tooltip similar to the principle of the ultrasonic vibration-assisted machining process. However, presented fixtures do not need an electricity source and utilize mainly forced and self-excited oscillations. In general, the tool vibrations during the cutting process are recognized as a negative phenomenon as it causes a shortening of the tool life and worsens the roughness of the machined surfaces. However, a deeper understanding of the cutting process proposes possible positive effects of tool vibration in terms of chip shapes, flank wear, chip volume coefficient, and quality of the machined surface. Experimentally obtained dependence of mentioned quantities is provided in the paper.