Ultrasonic Vibration-assisted Turning Research Articles

Investigation of conventional and ultrasonic vibration-assisted turning of hardened steel using a coated carbide tool

This study compares conventional turning (CT) and ultrasonic vibration-assisted turning (UVAT) in machining hardened AISI 52100 steel (62 HRC) with a PVD-coated TiAlSiN carbide tool. UVAT experiments, utilizing an ultrasonic frequency of 20 kHz and vibration amplitude of 20 µm, varied the cutting speed, feed, and depth of cut. Remarkably, UVAT reduced tool wear, extending tool longevity. Surprisingly, power consumption showed no significant differences between CT and UVAT. Mathematical models based on experimental data highlight the substantial impact of the cutting speed on tool wear, followed closely by the depth of cut. For power consumption, the depth of cut took precedence, with the cutting speed and feed rate playing pronounced roles in UVAT. This emphasizes the potential for further research on machinability, particularly exploring different vibration directions on the tool in feed, tangential, and radial aspects.

Experimental investigations on ultrasonic assisted turning of magnesium silicon carbide

ABSTRACT The conventional turning (CT) of Mg-SiC was found difficult due to high tool wear and surface roughness, which reduced the machinability of the composites. In this paper, a study applying ultrasonic vibration assisted turning (UAT) along with minimum quantity lubrication (MQL) is proposed to improve the machinability of Mg-SiC. The input parameters used in this work are spindle speed (SS), feed rate (FR), depth of cut (DOC), and percentage intensity of ultrasonic power (PIUP). The flank wear morphology of the cutting tool and average surface roughness (Ra) of the workpiece is studied. In addition, the surface topography of machined samples was studied by AFM to assess the surface quality. The results show that UAT with MQL reduces the Ra by 21% and 7% compared to CT and UAT at dry cutting conditions. The flank wear (Vb) decreased by 15% compared to dry UAT.

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 integrity analysis of aluminum 3003 alloy during ultrasonic-vibration-laser assisted turning

Surface integrity of the machined surface is an important aspect considering their surface alterations, metallurgical effects, and mechanical characteristics during the machining process. Industries have been seeking a capable machining technology that can improve the machining process capabilities especially in an eco-friendly manner. Hybrid machining processes have shown significant improvement in machining performance when compared with the conventional turning (CT) process without using any cutting fluids. Moreover, a recently developed hybrid machining technology, that is, ultrasonic-vibration-laser assisted turning (UVLAT) has shown better machinability than the CT process. Therefore, an attempt has been made to improve the surface integrity of aluminum 3003 alloy in terms of machining forces, surface roughness, surface damage, microstructure, microhardness, residual stresses, and corrosion behavior during the UVLAT process. A comparative surface integrity analysis has been performed among the CT, ultrasonic vibration assisted turning (UVAT), laser assisted turning (LAT), and UVLAT processes. Significant improvement in the surface integrity has been observed for the aluminum 3003 alloy during the UVLAT process in comparison to the CT, UVAT, and LAT processes. The periodic separation of the cutting tool and thermal softening of the workpiece material, simultaneously during the UVLAT process is the possible reason for the improvement in surface integrity. Results demonstrated that the UVLAT process has an excellent potential to enhance the surface integrity of aluminum alloys and is better than the CT, UVAT, and LAT processes.

Radial direction ultrasonic-vibration and laser assisted turning of Al3003 alloy

The utilization of various energy sources to assist the machining process has become prominent to obtain significant improvement in the machining performance. These energy sources have been utilized without using any cutting fluids which makes them eco-friendly. The combined action of laser and ultrasonic vibration energies during the turning process has shown significant achievement in machining process capabilities. Therefore, an attempt has been made to provide ultrasonic vibration in the radial direction and laser to preheat aluminium 3003 alloy simultaneously during the ultrasonic-vibration-laser assisted turning (UVLAT) process. Machining performance has been analyzed in terms of machining forces, machining temperature, chip morphology, surface damage, and surface roughness. A comparative machining performance analysis has been performed among the conventional turning (CT), ultrasonic vibration assisted turning (UVAT), laser assisted turning (LAT), and UVLAT processes. The outcomes of the present study revealed significant improvement in the machining performance for aluminium 3003 alloy during the UVLAT process. However, surface damage and surface roughness have been affected negatively during the UVLAT process due to the pin-point hammering and particle adhesion on the workpiece part. Hence, it can be said that the selection of vibration direction is a critical factor during the vibration machining processes.

Tool wear reduction in ultrasonic vibration-assisted turning of SiC-reinforced metal-matrix composite

In recent years, metal matrix composites (MMCs) have attracted the interest of various industrial sectors thanks to the benefits they offer in terms of lightness and mechanical properties compared to equivalent non-reinforced metallic alloys. Nevertheless, when machining MMCs, their heterogeneous structure, specifically characterized by the presence of hard particles within a much more ductile matrix, induces different thermal and mechanical loads when the cutting edge passes through the various composite constituents. This, in turn, may drastically reduce the cutting tool life as well as deteriorate the part surface integrity leading to poor in-service performances of the part. Nonconventional machining methods are usually employed to manufacture parts made of MMCs, nevertheless at the cost of scarce workpiece surface integrity and increased manufacturing burdens. To overcome the above-mentioned issues, ultrasonic vibration-assisted turning (UVAT) is proposed in this study as an efficient approach to machine MMCs. Turning trials with and without the application of ultrasonic vibration were carried out at varying cutting speeds, feed and volume of removed material. The tool wear mechanisms were identified and quantified. The surface finish and chip morphology were also analyzed as further machinability parameters for comparing the different machining approaches and assessing the advantages of UVAT. The obtained experimental results showed that the adoption of ultrasonic vibrations together with high feed can significantly increase the tool life, representing a suitable approach for efficiently machining MMCs.

Ultrasonic Vibration Assisted Turning of Inconel 825: An Experimental Analysis

ABSTRACT In this experimental analysis, ultrasonic-vibration-assisted-turning (UVAT) is introduced to machine Inconel 825 using TiAlN coated WC insert. Different turning conditions (varying ultrasonic power intensity, feed rate and cutting speed) are generated using response surface methodology. Turning performances like cutting force (Fc), temperature (T) and surface roughness (Ra) were analyzed through invasive weed optimization to distinct the critical turning parameter. Fc, T and Ra have been decreased by 34.99%, 20.61% and 24.73% in UVAT than CT, due to intermittent motion of the cutting tool. It minimizes the contact time between tool and workpiece, helps in better heat dissipation during machining and relieves excessive stress developed at tooltip that enhances tool life. TiAlN coating further curtailed the friction between tool-workpiece interfaces, improving surface quality, reducing stress, temperature and wear on the tool. Tool wear and chip morphology is analyzed with SCM, and XRD is utilized to identify crystallographic analysis and residual stress..

Hybrid turning process by interacting ultrasonic vibration and laser energies

ABSTRACT Hybrid machining processes are developed to achieve enhanced machining performance for various materials. In this study, ultrasonic vibration and laser sources interact simultaneously during the hybrid turning process and the process is termed ultrasonic vibration laser-assisted turning (UVLAT). Ultrasonic vibration-assisted turning (UVAT) fixture is mounted along with laser assisted turning (LAT) fixture on the lathe machine during the developed hybrid process. An experimental investigation on aluminum 3003 alloy is performed to analyze the machining performance for conventional turning (CT), UVAT, LAT, and UVLAT. Cutting speed and laser power are varied to machine aluminum alloy during various processes. The investigation shows that lower machining forces, higher machining temperature, smooth and lesser segmented chips, and lower surface roughness are obtained during UVLAT in comparison to CT, UVAT, and LAT. At higher cutting speed, machining forces and surface roughness are increased and decreased at higher laser power, whereas vice versa to machining temperature with variation in speed and power. Smooth edges and less segmentation are observed at higher laser power and cutting speed. Outcomes suggest that the machining performance of aluminum alloy is enhanced during the UVLAT process when compared with other processes.

Effect of thermo-mechanical loading on machining induced residual stresses in ultrasonic vibration assisted turning of Ti6Al4V alloy

The study of residual stresses induced during machining is of considerable importance due to their effect on fatigue life of machined components. The metallurgical changes occurred due to thermo-mechanical phenomenon in cutting process affects the distribution of residual stress in machined components. Ultrasonic vibration assisted turning (UVAT) is effective machining process for low thermal conductivity materials like Ti6Al4V alloy and improves the surface characteristics by reducing cutting force and cutting temperature. In this paper, experimental and finite element (FE) studies are conducted to study the circumferential and axial residual stress distribution in UVAT of Ti6Al4V alloy. FE model is developed to study the effect of vibrating parameter (ultrasonic power intensity) and cutting parameters (cutting speed, feed rate, and depth of cut) on the residual stress profiles of machined surface. The FE simulation results of cutting force and cutting temperature are validated with experimental results. The circumferential and axial surface residual stresses obtained from FE simulation are also compared with experimental results using X-ray diffraction method. The effect of thermo-mechanical loading on residual stress distribution is analyzed with respect to force components (cutting force and feed force) and cutting temperature. Finally, the effect of each cutting parameter on subsurface layer of machined component is analyzed.

Experimental investigation on magnesium AZ31B alloy during ultrasonic vibration assisted turning process

ABSTRACT Magnesium alloys generate harmful emissions while using coolants during the machining process and it affects both the operator and the environment. Ultrasonic vibration assisted turning (UVAT) is an eco-friendly and advanced machining process to machine various materials than conventional turning (CT). In this study, experimental analysis is carried out to investigate the machinability of the magnesium AZ31B alloy during CT and UVAT processes. The effect of cutting speed during the processing of magnesium AZ31B alloy is analyzed and compared with CT in terms of machining forces, machining temperature, tool wear, chip morphology, surface roughness, microstructure, and microhardness. Results showed that compared with CT, machining forces and surface roughness is reduced significantly in UVAT. However, higher machining temperature is obtained during UVAT than CT. Flank wear is observed during CT although negligible tool wear is observed for UVAT. Chip segmentation is obtained for both CT and UVAT whereas higher chip thickness is observed for UVAT than CT process. Finer grains and higher microhardness are obtained in UVAT than the coarse grains and lower microhardness in CT. The results showed that the processing of magnesium AZ31B alloy during the UVAT process leads to enhanced machining performance compared to the CT process.

Experimental study of machined surface quality in ultrasonic vibration-assisted turning of 5A06 Al-Mg alloy

The 5A06 Al-Mg alloy is a soft material, and the phenomenon of knife sticking is extremely serious during cutting, likewise, it is easy to generate build-up edges. Therefore, it is difficult to acquire good surface quality in turning. For this purpose, the ultrasonic theory and cutting theory are fully combined in this study, and the machining mechanism of conventional turning (CT) is changed by applying ultrasonic vibration (UV) to the cutting tool, so as to build up the machining results. The turning experiments of 5A06 Al-Mg alloy with or without UV are carried out under different process parameters, and through which the effects of ultrasonic amplitude (UA), feed rate (FR), cutting depth (CD) and cutting speed (CS) on the surface roughness of machined workpiece are investigated and analyzed. The consequences show that the process parameters have a different degree of effect on surface roughness. And there are special process parameters suitable for UV assisted turning (UAT), under which the processing results of UAT is obviously better than that of CT. In addition, it is found that by contrast experiment of surface topography under ideal process parameters built-up edges, surface scratches and other phenomena are not easy to arise in UAT to obtain the better surface topography than CT.

Surface Texturing Technique Based on Ultrasonic Turning for Improving Tribological Properties

Tribological properties such as lubrication, friction, and wear resistance greatly affect machine operation efficiency, performance, and service life. Surface texturing methods such as scraping can be used to improve these properties. Scraping creates many small depressions on the target surface. These depressions, which are evenly distributed, function as oil holes and thus improve lubrication performance. This paper describes a surface texturing technique based on ultrasonic vibration-assisted turning (UVAT) that simultaneously improves tribological properties and machinability. In UVAT, the cutting tool is oscillated mainly in the principal direction. Vibration in the radial direction, which is induced by Poisson deformation, periodically digs up or pushes the workpiece surface in the radial direction, creating a textured surface. A surface subjected to UVAT has periodic depressions along the workpiece rotation direction. The texturing rate of UVAT is up to 6700 mm2/min, which is higher than that of manual scraping. To evaluate the tribological performance of a surface textured by UVAT, the friction coefficient between a stainless steel pin and the surface was measured under oil dipping conditions. The results of friction experiments show that the friction coefficient of the UVAT-treated surface and its fluctuation were lower than those of a conventional turned surface. The UVAT-treated surface had stable friction properties.

Experimental investigations on the ultrasonic vibration-assisted hard turning of AISI 52100 steel using coated carbide tool

Ultrasonic vibration-assisted turning (UVAT) is a hybrid and eco-friendly machining technique. The UVAT is performed by superimposing high frequency and low amplitude sound waves on the cutting tool in conventional turning. In the present work, a comparative evaluation of the machining performance is presented during conventional turning (CT) and ultrasonically vibration-assisted turning (UVAT) of AISI 52100 hardened steel (62 HRC). Hard turning experiments were performed using a PVD coated TiAlSiN carbide tool considering the effect of process parameters such as cutting speed, feed, and depth of cut. The performance is measured in terms of cutting force and surface roughness. This study observed a better surface finish during of around 8.29% in UVAT when compared to conventional turning. Better surface finish achieved under UVAT could be attributed to better chip breaking and disentanglement of the chip around the tool during UVAT against long curly chips produced that further entangled on the tool while CT. These entangled long curly chips affected the surface finish. On the other hand, no significant difference is observed in cutting force while hard turning under CT and UVAT. This is mostly due to the fact that, although UVAT has less cutting force at slower cutting speeds, but it behaves very identically with CT when cutting speed approaches tangential velocity. This study finds further scope for machinability studies considering the effect of vibrations superimposed on a tool in feed, tangential, and radial directions.

FE analysis of Ultrasonic vibration assisted turning of magnesium AZ31B alloy

Ultrasonic vibration assisted turning (UVAT) is advanced machining process where vibrational assistance of high frequency and low amplitude is provided to tool. In the present study, a two dimensional (2D) numerical simulation is carried out in ABAQUS/Explicit to compare the machinability of AZ31B magnesium alloy with tungsten carbide as a cutting tool during the conventional turning (CT) and UVAT processes. The objective of this study is to compare the effective stress distribution, cutting and thrust forces, and machining temperature during the CT and UVAT processes. The simulation results showed that the average stress distribution during UVAT is reduced to about 40% compared with CT. However, the average stress distribution is comparable during CT and the penetration stage of the UVAT process. Furthermore, the average cutting and thrust forces were reduced by 69% and 65% respectively in UVAT than CT. Although, the machining temperature in UVAT is found to be around 37% higher than that in CT. The results revealed that the UVAT has many advantages over CT and the machinability can be improved significantly by incorporating vibrations to the conventional turning process.

A Fuzzy Logic Model for the Analysis of Ultrasonic Vibration Assisted Turning and Conventional Turning of Ti-Based Alloy.

Titanium and its alloys are largely used in various applications due its prominent mechanical properties. However, the machining of titanium alloys is associated with assured challenges, including high-strength, low thermal conductivity, and long chips produced in conventional machining processes, which result in its poor machinability. Advanced and new machining techniques have been used to improve the machinability of these alloys. Ultrasonic vibration assisted turning (UVAT) is one of these progressive machining techniques, where vibrations are imposed on the cutting insert, and this process has shown considerable improvement in terms of the machinability of hard-to-cut alloys. Therefore, selecting the right cutting parameters for conventional and assisted machining processes is critical for obtaining the anticipated dimensional accuracy and improved surface roughness of Ti-alloys. Hence, fuzzy-based algorithms were developed for the ultrasonic vibration assisted turning (UVAT) and conventional turning (CT) of the Ti-6Al7Zr3Nb4Mo0.9Nd alloy to predict the maximum process zone temperature, cutting forces, surface roughness, shear angle, and chip compression ratio for the selected range of input parameters (speed and depth-of-cut). The fuzzy-measured values were found to be in good agreement with the experimental values, indicating that the created models can be utilized to accurately predict the studied machining output parameters in CT and UVAT processes. The studied alloy resulted in discontinued chips in both the CT and UVAT processes. The achieved results also demonstrated a significant decline in the cutting forces and improvements in the surface quality in the UVAT process. Furthermore, the chip discontinuity is enhanced by the UVAT process due to the higher process zone temperature and the micro-impact imposed by the cutting tool on the workpiece.

Tool-Work Contact Ratio and Parametric Influence in Ultrasonic Vibration–Assisted Turning of Ti6Al4V Alloy

Abstract The performance of the machining process depends on the time of contact of the cutting tool with the workpiece. In this work, the effect of vibrating and cutting parameters on tool-work contact ratio (TWCR) in ultrasonic vibration–assisted turning (UVAT) is evaluated. Machining performance is measured in terms of average cutting force, cutting temperature, and average surface roughness. Full factorial experiments are conducted on a Ti6Al4V alloy to evaluate the performance of the UVAT process in terms of TWCR. The performance of the UVAT process is analyzed and compared with the conventional turning process at various conditions, such as intensity of ultrasonic power (80, 90, and 100 %), cutting speed (10, 30, and 50 m/min), feed rate (0.055, 0.103, and 0.161 mm/rev), and depth of cut (0.1, 0.3, and 0.5 mm). The cutting force, cutting temperature, and surface roughness are decreased with the increase in percentage intensity of ultrasonic power. The effectiveness of UVAT process is greater at higher levels of vibrating parameters and lower levels of cutting parameters in the selected range. Finally, it is concluded that the maximum benefit from the UVAT process is obtained at TWCR of 0.136 and its effect is dominant at lower levels of cutting conditions. However, the effect of thermal loading is dominant at higher levels of cutting conditions in the selected range.

Experimental Investigation on Flank Wear of the Tool in Ultrasonic Vibration-Assisted Turning of Ti6Al4V Alloy

Abstract High cutting temperatures developed during machining of Ti6Al4V alloy diminish the tool life by rapid increase in rate of tool wear. The high cutting temperatures increase the chemical reactivity of the workpiece with tool material and form the localized temperature zones at the vicinity of cutting tool edge. Ultrasonic vibration-assisted turning (UVAT) is an effective cutting technique in which tangential vibrations are provided to the cutting tool. The reduced cutting force and temperature improve the tool life in the UVAT process. In the present study, flank wear of the uncoated carbide cutting tool has been studied in UVAT processes at various cutting speeds (90, 120, and 150 m/min) and ultrasonic powers (80, 90, and 100 %). The flank wear of the tool is measured with a scanning electron microscope, and it is observed that tool wear is low in UVAT compared with the conventional turning (CT) process. Fracture of the cutting edge of the tool is observed in CT because of high compressive stresses with the high cutting temperature, which did not occur in the UVAT process. The growth of average and maximum flank wear with cutting velocity is low in UVAT, whereas rapid growth is observed in the CT process. From the experimental results, tool life improvement is observed in UVAT compared with CT at an average flank wear of 300 µm; however, this improvement is decreased with an increase in cutting speed in the order of 62, 53.2, and 32 % for 90, 120, and 150 m/min, respectively, at 100 % ultrasonic power. Similarly, tool life is improved with an increase in ultrasonic power in the order of 18, 55, and 62 % for 80, 90, and 100 % ultrasonic power, respectively, at 90 m/min cutting speed.

Damping Impact on 1-Dimensional Ultrasonic Vibration-Assisted Turning Machining

In ultrasonic vibration-assisted turning (UVAT), vibration is one of the critical factors that causes noise during machining and affects cutting tool life, machining accuracy and workpiece surface quality. Vibration generated by piezoelectric actuators tends to transmit undesired vibration on the edge of the cutting tool and tool post. This situation hinders the maximization of vibration energy usage in the cutting tool. Thus, this paper investigated the vibration performance in the cutting tool by adding an isolator pad as damping element in the static zone of a tool holder to reduce the resonance generated during the machining process. The static, vibration and surface roughness analysis has been performed to determine the impact of damping on the machining performance. The results revealed a significant improvement in surface roughness where the best Ra for UVAT was 0.38 μm. In addition, vibration and static analysis showed the application of isolator pad capable of reducing 80% of energy loses and a supporter to increase the displacement, respectively. Ultimately this innovative solution can play an important role in improving UVAT performance.

Damping Impact on 1-Dimensional Ultrasonic Vibration-Assisted Turning Machining

In ultrasonic vibration-assisted turning (UVAT), vibration is one of the critical factors that causes noise during machining and affects cutting tool life, machining accuracy and workpiece surface quality. Vibration generated by piezoelectric actuators tends to transmit undesired vibration on the edge of the cutting tool and tool post. This situation hinders the maximization of vibration energy usage in the cutting tool. Thus, this paper investigated the vibration performance in the cutting tool by adding an isolator pad as damping element in the static zone of a tool holder to reduce the resonance generated during the machining process. The static, vibration and surface roughness analysis has been performed to determine the impact of damping on the machining performance. The results revealed a significant improvement in surface roughness where the best Ra for UVAT was 0.38 μm. In addition, vibration and static analysis showed the application of isolator pad capable of reducing 80% of energy loses and a supporter to increase the displacement, respectively. Ultimately this innovative solution can play an important role in improving UVAT performance.

Experimental study on cutting force in ultrasonic vibration-assisted turning of 304 austenitic stainless steel

The generation mechanism of cutting force in ultrasonic vibration assisted turning (UAT), with the composition and decomposition of cutting force is discussed in this paper, and the model of cutting force in UAT is established based on the mechanism of UAT. The force measuring test system is designed on the basis of the established machining system of UAT. The contrast experiments for turning the workpiece of 304 austenitic stainless steel are conducted with and without ultrasonic vibration under different technological parameters. Furthermore, the relational model and correlation between technological parameters and cutting force is obtained by regression analysis and variance analysis. Thereby, the mutual relation among these technological parameters is effectively controlled, which contributes to achieving the high quality and high efficient processing. Simultaneously, the influences of single technological parameter with the interaction between technological parameters on cutting force are researched and analyzed. The results prove that the cutting force is reduced significantly with the aid of ultrasonic vibration in turning and the choice of the proper ultrasonic amplitude, there is an optimal range of ultrasonic amplitudes as well. Meanwhile, the cutting parameters have great influence on cutting force, among which depth of cut has the superior influence, then the cutting speed, and feed rate has the minimal influence. Moreover, cutting parameters should not be too large, UAT is mainly used for semi-finishing or finishing at medium-low speed. UAT will get more ideal machining effect if cutting parameters are chosen properly.