Introduction Of Ultrasonic Vibration Research Articles

Effect of Ultrasonic Vibration on Microstructure and Antifouling Capability of Cu-Modified TiO2 Coating Produced by Micro-Arc Oxidation

Ti and its alloys have received wide attention in marine engineering. However, the limited anti-biofouling capability may hinder their wide application. In the present work, micro-arc oxidation (MAO) with and without the introduction of ultrasonic vibration (UV) has been conducted on metallic Ti substrate in an aqueous solution containing Na2Cu-EDTA to produce a Cu-modified TiO2 coating. Microstructural characterization reveals that the introduction of UV increased the thickness of the coating (ranging from ~13.5 μm to ~26.2 μm) compared to the coating (ranging from ~8.1 μm to ~12.8 μm) without UV. A relatively higher Cu content (~2.13 wt.%) of the coating with UV relative to the coating (~1.39 wt.%) without UV indicates that UV enhances the incorporation of Cu into TiO2. Further, both electrochemical properties and the response to sulfate-reducing bacteria (SRB) were evaluated, revealing that UV introduction endows Cu-modified TiO2 coating with enhanced corrosion resistance and antifouling capability. The present results suggest that ultrasound-auxiliary micro-arc oxidation (UMAO) obviously enhances the surface performance of Ti alloys for promising applications in marine engineering.

Grindability Evaluation of Ultrasonic Assisted Grinding of Silicon Nitride Ceramic Using Minimum Quantity Lubrication Based SiO2 Nanofluid

Minimum quantity Lubrication (MQL) is a sustainable lubrication system that is famous in many machining systems. It involve the spray of an infinitesimal amount of mist-like lubricants during machining processes. The MQL system is affirmed to exhibit an excellent machining performance, and it is highly economical. The nanofluids are understood to exhibit excellent lubricity and heat evacuation capability, compared to pure oil-based MQL system. Studies have shown that the surface quality and amount of energy expended in the grinding operations can be reduced considerably due to the positive effect of these nanofluids. This work presents an experimental study on the tribological performance of SiO2 nanofluid during grinding of Si3N4 ceramic. The effect different grinding modes and lubrication systems during the grinding operation was also analyzed. Different concentrations of the SiO2 nanofluid was manufactured using canola, corn and sunflower oils. The quantitative evaluation of the grinding process was done based on the amount of grinding forces, specific grinding energy, frictional coefficient, and surface integrity. It was found that the canola oil exhibits optimal lubrication performance compared to corn oil, sunflower oil, and traditional lubrication systems. Additionally, the introduction of ultrasonic vibrations with the SiO2 nanofluid in MQL system was found to reduce the specific grinding energy, normal grinding forces, tangential grinding forces, and surface roughness by 65%, 57%, 65%, and 18% respectively. Finally, regression analysis was used to obtain an optimum parameter combinations. The observations from this work will aid the smooth transition towards ecofriendly and sustainable machining of engineering ceramics.

The microstructure and high-temperature oxidation resistance of Si-rich Mo-Si-B coatings prepared by ultrasonic vibration assisted laser cladding

Si-rich Mo-Si-B powders (Mo-62Si-5B at%) were deposited on Nb-Si based alloy by laser cladding assisted with ultrasonic vibration. The obtained coatings mainly consist of MoSi2 and (Mo, X)5Si3 (X = Nb and Ti). With the introduction of ultrasonic vibration during laser cladding, the lath-shaped MoSi2 phase transforms into cellular gradually. Meanwhile, the discrepancy on the microstructure of the top region and the bottom region is eliminated gradually, indicating that the cavitation and acoustic streaming of ultrasonic vibration not only refines the microstructure, but also homogenizes the element and phase distribution in the coatings. High-temperature oxidation experiment at 1250 ℃ were conducted to assess the oxidation resistance of the coatings. Compared with Nb-Si alloy, the coated specimens have much lower oxidation weight increase. Furthermore, with the assistance of ultrasonic vibration, the oxidation resistance of the coating is enhanced further. The oxide scales on the coatings consist of two layers: an upper amorphous aluminoborosilica with TiO2 particles dispersed and a lower crystalline SiO2 layer. With the introduction of ultrasonic vibration, the microstructure of the coatings is refined, resulting in more phase and grain boundaries in the coatings. Therefore, the diffusion of the elements to the surface is accelerated and the protective oxide scale can be formed quickly.

Tensile fracture test of nanocomposite ceramics under ultrasonic vibration based on nonlocal theory

Based on non-local theory, the dispersion characteristics of ultrasonic vibration in Specimen tension are analyzed, and the effects of ultrasonic frequency and amplitude on the wave dispersion are obtained through theoretical analysis. Tensile tests were carried out using an ultrasonic vibration system and specimens, and the test process as well as test parts were observed and analyzed. The influence of the ultrasonic vibration on fracture properties and the change of grain micro-organization under different loading conditions were verified by experiments. The introduction of ultrasonic vibration changes the internal stress of the ceramic fracture, affects the hardness of the workpiece, and also leads to the scattering of particles, which leads to the aggravation of ultrasonic attenuation and phase velocity dispersion. SEM and XRD analyses showed that with the increase in ultrasonic frequency and amplitude，the trans -granular fracture was more obvious, the micro-cracks and dimples increased, and micro-pores increased in size and number. The tensile stress produced by ultrasonic vibration will induce the transformation from T-phase ZrO2 particles to M-phase ZrO2 particles and absorb strain, which greatly improves the plastic mechanical properties of nanocomposite ceramics. Due to the inherent phase transformation toughening mechanism, the material improves the plastic mechanical properties under the ultrasound excitation, and it is easier to achieve ductile domain processing.

Ultra-rapid and low-temperature soldering of hypereutectic Al-Si alloys by ultrasonic-assisted soldering with In interlayer in air for electronic application

Hypereutectic Al-Si alloys were soldered by an ultrasonic-assisted soldering with In interlayer for only 0.1 s at 160 °C in air. The introduction of ultrasonic vibration into the soldering process promoted the formation of the liquid phase by its acoustic softening effect, ultrasonic cavitation effect and acoustic streaming. The effects of ultrasonic vibration on the formation of Al-In liquid phase were also discussed. The microstructure evolution of solder joint and the migration of Si particles were influenced by ultrasonic vibration. The complex solder joint obtained by the ultrasonic-assisted approach consisted of Si particles and Al-In solid solution. Si particles could be regarded as tracers and reinforced phase. The influence of ultrasonic vibration time, pressure and temperature on the microstructure of the solder joint was investigated. The effect of ultrasonic vibration on shear strength of the joints was also discussed. Image-Pro-Plus Analysis was used to estimate content of Si particles in solder joint. The shear strength of the joints was obtained, when the suitable ultrasonic vibration time, temperature and pressure were chosen.

Investigations on the micro-interactions of grit-workpiece and forces prediction in ultrasonic vibration side grinding of optical glass

The cutting force in ultrasonic vibration side grinding (UVSG) of brittle materials is of significance for the machined quality. However, the micro-interaction mechanism between abrasive grits and workpiece remains a significant issue in terms of the research on cutting forces in the brittle material grinding due to the stochastic distribution nature of the grits. Meanwhile, these micro-interactions are further affected by ultrasonic vibration in UVSG process. Considering these issues, this paper aims at modeling the cutting force affected by the stochastically distributed grits and ultrasonic vibration to reveal the multi-scale grinding mechanics in UVSG of optical glass. Through modeling the stochastic grinding wheel surface and analyzing the kinematics of multi-grits, the unified motion trajectory and the instantaneous chip thickness in UVSG were enabled to derived to determine the different grit-workpiece interaction stages. With consideration of the ultrasonic vibration effects on the micro-interactions, a novel theoretical cutting force model was developed based on the analysis of force generated at three interaction stages, i.e., rubbing, plowing, and cutting stages. The numerical simulations of this model could provide the time-domain variation features of cutting forces to evaluate the fluctuations and trends of the cutting forces from multi-scales. Experimental verifications indicated that the cutting force and its fluctuations are within the acceptable error margin. Furthermore, a thorough analysis of force fluctuating situations at different ultrasonic vibration amplitudes was conducted. The analytical results indicated that an increase in ultrasonic vibration amplitude was not only beneficial to restrain the force fluctuation, but helpful to reduce the brittle fracture damages of optical glass. The evolution trend of cutting force in different grinding conditions and wheel specifications were discussed in detail to reveal the influence mechanisms of machining parameters on the cutting forces. Afterwards, the detection results of ground workpieces demonstrate that the introduction of ultrasonic vibration would improve the machined quality of optical glass in UVSG process.

Construction of multi-layered Zn-modified TiO2 coating by ultrasound-auxiliary micro-arc oxidation: Microstructure and biological property

Surfaces with desirable cytocompatibility and bactericidal ability are favoured for orthopaedic implants to stimulate osteogenic activity and to prevent implant-associated infection. In this work, we creatively introduce ultrasonic vibration (UV) to micro-arc oxidation (MAO) process and explore its influence on the microstructure, corrosion property and biological responses of Zn-modified TiO2 coating. With the introduction of UV, a uniform surface layer with homogeneously-distributed clusters could be produced as the outer layer, which possesses a fusion band with the underlying TiO2. The microstructural modification associated with UV results in the enhanced corrosion resistance, increased adhesive strength and improved biological performances of the resultant coating relative to that with the absence of UV. Hence, the ultrasonic auxiliary micro-arc oxidation (UMAO) is regarded as a promising surface modification method to produce Ti-based orthopaedic implants of high quality.

Enhanced uniformity, corrosion resistance and biological performance of Cu-incorporated TiO2 coating produced by ultrasound-auxiliary micro-arc oxidation

To achieve a uniform surface layer with enhanced corrosion resistance, antibacterial capability and cytocompatibility on the titanium (Ti)-based orthopaedic implant, ultrasound-auxiliary micro-arc oxidation (UMAO) was carried out on Ti substrate to fabricate a Cu-incorporated TiO2 coating. Instead of the co-existence of central brown area and peripheral black area in the Cu-incorporated TiO2 coating fabricated by conventional micro-arc oxidation, a uniform brownish appearance could be achieved after the introduction of ultrasonic vibration (UV). The introduction of UV also significantly modifies the elemental composition, phase component and chemical configuration of the coating, which exhibits a bi-layered structure with the porous TiO2 as the inner layer and the amorphous Ca, P, O and Cu component as the outer layer. Finally, electrochemical measurement and in vitro biological tests indicate that the introduction of UV is conducive to corrosion resistance, antibacterial capability and cytocompatibility of the Cu-incorporated TiO2 coating.

Preparation of in-situ TiB2 reinforced aluminum matrix composites assisted by two steps of ultrasonic vibration

The TiB2/Al particle reinforced composites were prepared successfully through metal-salt reaction with different process conditions (mechanical stirring, one-stage and two-stages of ultrasonic vibration). It was usually taken more than 60 min to complete metal-salt reaction under mechanical stirring condition, lots of reinforcement agglomerations and residual intermediate such as Al3Ti was in the matrix. The reaction time was greatly shortened from 60 min to 5 min and particle agglomerations were eliminated successfully by the introduction of ultrasonic vibration at 850 °C. Through the introduction of ultrasonic vibration at 730 °C, not only most of the residual Al3Ti phase was broken or dissolved, but also the size of TiB2 was refined. The composite prepared by two-stage ultrasonic vibration has the optimal improvements of yield strength and ultimate tensile strength, which increased by are 108% and 98% respectively, hardness increased 61.5%. When only introducing the first stage of UVT, the elongation decreased from 34% to 20% owning to lots of rod-like Al3Ti in the matrix, after the second stage of UVT, the elongation restored to 33%. The effects of ultrasonic vibration on phase transformation, microstructure, and mechanical properties were studied by x-ray diffraction (XRD), optical microscope (OM), scanning electron microscope (SEM) and Electron Backscattered Diffraction (EBSD). Moreover, the effects of Orowan strengthening, thermal expansion mismatch strengthening, and grain refinement strengthening on mechanical properties were also discussed.

Microstructure Evolution and Strengthening Mechanism of Galvanized Steel/Mg Alloy Joint Obtained by Ultrasonic Vibration-Assisted Welding Process.

A novel ultrasonic vibration-assisted welding (UVAW) process was used to achieve reliable joining of galvanized steel and Mg alloy. The effects of the UVAW technique on the microstructure and mechanical properties of galvanized steel/Mg alloy weldment were studied in detail. The introduction of ultrasonic vibration can ameliorate the wetting of welds and eliminate porosity defects. A refined microstructure of the fusion welding zone with an average grain size of 39 ± 1.7 µm was obtained and attributed to cavitation and acoustic streaming caused by the UVAW process. The grain refinement led to an increase in the microhardness and joining strength of the galvanized steel/Mg alloy weldment. Under the ultrasonic power of 0.9 kW and a current of 65 A, the maximum joining strength of the ultrasound-treated galvanized steel/Mg alloy joint was 251 ± 4.1 MPa, which was a 14.6% increase over the joint without ultrasonic treatment.

Influence of the ultrasonic vibration amplitude on the melt pool dynamics and the weld shape of laser beam welded EN AW-6082 utilizing a new excitation system for laser beam welding

Laser beam welding is a commonly used technology for joining similar and dissimilar materials. In order to improve the mechanical properties of the weld, the introduction of ultrasonic vibration into the weld zone has been proposed [5]. The ultrasonic system consists of an electronic control, a power supply, a piezoelectric converter and a sonotrode, which introduces the vibration into the weld zone. Its proper design is of great importance for the process performance. Furthermore, the effects of ultrasound in a melt pool need to be understood to evaluate and optimize the process parameters. In addition, it is important to find out the limits of ultrasonic excitation with respect to a maximum vibration amplitude. Therefore, firstly different methods of ultrasonic excitation are investigated and compared with respect to their performance. A system which is based on using longitudinal vibrations turns out to be the best alternative. Secondly, the system design is described in detail to understand the boundary conditions of the excitation and finally, simulations about the influence of ultrasonic vibrations are done by using a simplified model. The system is used to perform experiments, which aim at detecting the maximum vibration amplitude doing bead on plate welds of EN AW-6082 aluminum alloy. The experiments reveal a significant change of the weld shape with increasing ultrasonic amplitude, which matches the simulative findings. If the amplitudes are small, there is a marginal effect on the weld shape. If the amplitudes are high, melt is ejected and the weld shape is disturbed. In the present case, amplitudes over 4 µm were found to disturb the weld shape.

Effect to the Surface Composition in Ultrasonic Vibration-Assisted Grinding of BK7 Optical Glass

Because of the changes in cutting conditions and ultrasonic vibration status, the proportion of multiple material removal modes are of uncertainty and complexity in ultrasonic vibration-assisted grinding of optical glass. Knowledge of the effect of machined surface composition is the basis for better understanding the influence mechanisms of surface roughness, and also is the key to control the surface composition and surface quality. In the present work, 32 sets of experiments of ultrasonic vibration-assisted grinding of BK7 optical glass were carried out, the machined surface morphologies were observed, and the influence law of machining parameters on the proportion of different material removal was investigated. Based on the above research, the effect of surface composition was briefly summarized. The results indicated that the increasing of spindle rotation speed, the decreasing of feed rate and grinding depth can improve the proportion of ductile removal. The introduction of ultrasonic vibration can highly restrain the powdering removal, and increase the proportion of ductile removal. Grinding depth has a dominant positive effect on the surface roughness, whereas the spindle rotation speed and ultrasonic amplitude both have negative effect, which was caused by the reduction of brittle fracture removal.

Investigation on the material flow and deformation behavior during ultrasonic-assisted incremental forming of straight grooves

The introduction of ultrasonic vibration is proved to be beneficial for the reduced force and improved formability for sheet forming processes. However, the vibration-induced material behavior is still not satisfactorily explained. The objective of this work is to investigate the effect of the ultrasonic vibration on the material flow characteristics and the plastic deformation mechanism during the incremental sheet forming of the straight groove. Both analytical and finite element models are established to explore the impacts of ultrasonic amplitude, frequency, step-down size and feed rate on material flow characteristics. It was found that the material flow area was dramatically increased after applying the ultrasonic vibration, and the influence of ultrasonic amplitude on material flow area is greater than that of frequency, which is similar to the effect of acoustic softening. In addition, the separation effect under different amplitudes and frequencies was analyzed through finite element modeling to partly explain the reduction of forming forces. The duty cycle was decreased as the amplitude increases as well as the frequency. Furthermore, the material flow behavior and the force reduction rate for different tool paths are explored. Finally, experiments were performed which further verified the reliability of the analytical and FE models. These findings provide a theoretical basis for further investigation of the mechanisms of ultrasonic-assisted incremental sheet forming process.

Role of Acoustic Streaming in Formation of Unsteady Flow in Billet Sump during Ultrasonic DC Casting of Aluminum Alloys.

The present work investigated melt flow pattern and temperature distribution in the sump of aluminum billets produced in a hot-top equipped direct chilling (DC) caster conventionally and with ultrasonic irradiation. The main emphasis was placed on clarifying the effects of acoustic streaming and hot-top unit type. Acoustic streaming characteristics were investigated first by using the earlier developed numerical model and water model experiments. Then, the acoustic streaming model was applied to develop a numerical code capable of simulating unsteady flow phenomena in the sump during the DC casting process. The results revealed that the introduction of ultrasonic vibrations into the melt in the hot-top unit had little or no effect on the temperature distribution and sump profile, but had a considerable effect on the melt flow pattern in the sump. Our results showed that ultrasound irradiation makes the flow velocity faster and produces a lot of relatively small eddies in the sump bulk and near the mushy zone. The latter causes frequently repeated thinning of the mushy zone layer. The numerical predictions were verified against measurements performed on a pilot DC caster producing 203 mm billets of Al-17%Si alloy. The verification revealed approximately the same sump depth and shape as those in the numerical simulations, and confirms the frequent and large fluctuations of the melt temperature during ultrasound irradiation. However, the measured temperature distribution in the sump significantly differed from that predicted numerically. This suggests that the present mathematical model should be further improved, particularly in terms of more accurate descriptions of boundary conditions and mushy zone characteristics.

Fracture test of nanocomposite ceramics under ultrasonic vibration based on nonlocal theory

Based on the non-local theory, the dispersion characteristics of ultrasonic vibration in three-point bending are analyzed, and the effects of ultrasonic frequency and amplitude on the dispersion characteristics are obtained through theoretical analysis. Three-point bending tests were carried out using an ultrasonic vibration system and specimens, and the test process as well as the workpiece after the test were observed and analyzed. The effects of ultrasonic vibration on fracture properties and crack growth mechanism of ceramics under different loading conditions were verified by experiments. The introduction of ultrasonic vibration changes the internal stresses of the ceramic fracture, affects the hardness of the workpiece, and also causes the scattering of particles, which leads to the intensification of ultrasonic attenuation and phase velocity dispersion. SEM and XRD analysis showed that with the increase in ultrasonic frequency and amplitude, the transgranular fracture was more obvious, tearing edges and dimples increased, and microvoids increased in size and number. Ultrasonic vibration can cause ZrO2 to undergo t-m phase transformation under stress induction and absorb the strain, thus greatly improving the mechanical properties of nanocomposite ceramics. Due to the toughening mechanism of the inherent phase transformation, the material has improved plastic mechanical properties, and it is easier to achieve ductile domain processing.

Ultrasonic vibration-assisted laser engineering net shaping of ZrO2-Al2O3 bulk parts: Effects on crack suppression, microstructure, and mechanical properties

Laser additive manufactured zirconia-alumina ceramic (ZrO2-Al2O3) parts demonstrate severe problems resulting from cracking and inhomogeneous material dispersion. To reduce these problems, we propose a novel ultrasonic vibration-assisted laser engineered net shaping (LENS) process for fabrication of bulk ZrO2-Al2O3 parts. Results showed that the initiation of cracks and the crack propagation were suppressed in the parts fabricated by LENS process with ultrasonic vibration. For the parts fabricated without ultrasonic vibration, the sizes of cracks decreased with the increase of laser power. Scanning electron microscope analyses proved that the introduction of ultrasonic vibration was beneficial for grain refinement and uniform material dispersion. Due to the suppressed cracking, refined grains, and homogenized material dispersion, the parts fabricated with ultrasonic vibration demonstrated better mechanical properties (including higher microhardness, higher wear resistance, and better compressive properties), compared with the parts fabricated without ultrasonic vibration.

Parametric study of ultrasonic-assisted hole sinking micro-EDM of titanium alloy

Making miniature holes of acceptable tolerances in titanium alloys by conventional drilling is difficult due to frequent tool failure because of its poor thermal conductivity, high hardness, and high chemical affinity with cutting tool materials. Micro-electrical discharge machining (micro-EDM) has been found as a suitable method of machining of miniature holes in titanium alloys but it faces some problems such as improper flushing of the debris, arcing, short-circuiting, frequent adhesion of tool electrode with workpiece, and poor machining rate. To overcome all these problems, authors have developed a new ultrasonic-assisted micro-EDM setup and fitted to already available ZNC-EDM machine. The objective of the present work is to study experimentally the effect of gap current (I g), pulse on-time (T on), pulse off-time (T off), and ultrasonic power (U P) on material removal rate (MRR), tool wear rate (TWR), and hole taper (T a) due to ultrasonic-assisted hole sinking micro-EDM (UA-HS-MEDM) in titanium alloy workpiece. Experimental results reveal that introduction of ultrasonic vibration in hole sinking micro-EDM (HS-MEDM) has significant effect on MRR, TWR, and T a. A comparative observation regarding recast layer and circularity of microholes made by HS-MEDM with and without ultrasonic vibration has also been reported.

Ultrasonic vibration assisted grinding of hard and brittle linear micro-structured surfaces

In this paper, a novel ultrasonic vibration assisted grinding (UVAG) technique was presented for machining hard and brittle linear micro-structured surfaces. The kinematics of the UVAG for micro-structures was first analyzed by considering both the vibration trace and the topological features on the machined surface. Then, the influences of the ultrasonic vibration parameters and the tilt angle on the ground quality of micro-structured surfaces were investigated. The experimental results indicate that the introduction of ultrasonic vibration is able to improve the surface quality (The roughness SRa was reduced to 78nm from 136nm), especially in guaranteeing the edge sharpness of micro-structures. By increasing the tilt angle, the surface roughness can be further reduced to 56nm for a 59% improvement in total. By using the preferred UVAG parameters realized by orthogonal experiments, a micro cylinder array with surface roughness of less than 50nm and edge radius of less than 1μm was fabricated. The primary and secondary sequence of the grinding parameters obtained by the orthogonal experiments are as follows: feed rate, tilt angle of workpiece, depth of grinding, vibration frequency and amplitude. The spindle speed in the range of 1000rpm–3000rpm does not significantly affect the machined micro-structured surface roughness. Finally, more micro-structures including a micro V-groove array and a micro pyramid array were machined on binderless WC as well as SiC ceramic by means of the UVAG technique. The edge radius on the V-grooves and pyramids are both less than 1μm, indicating the feasibility of UVAG in machining hard and brittle micro-structured surfaces for an improved surface quality.

Experimental Investigation on Surface/Subsurface Damage in Rotary Ultrasonic Machining of Glass BK7

Experiments were carried out to study the effect of ultrasonic vibration on the surface roughness and subsurface damage (SSD) in rotary ultrasonic machining (RUM) of glass BK7. As a comparison, some conventional grinding (CG) experiments were also performed under the same process parameters with there of the RUM ones. The surface roughness of the RUM/CG samples was measured with a surface profilometer. The SSD of these specimens was assessed and characterized by a measuring microscope with the help of the taper polishing method. Also, the influence of process parameters (cutting depth, feed speed, and spindle speed) on the surface/subsurface quality was discussed. As a result, both the surface roughness and the SSD depth of the RUM/CG specimens were reduced with the increased spindle speed, while increased with the increasing of feed speed and cutting depth of the diamond tool. Compared with the CG process, the introduction of ultrasonic vibration resulted in the higher surface roughness and SSD depth, due to the fact that the max cutting depth of the abrasive in the RUM process increased by an amplitude compared with that in the CG process.

Chemo-mechanical manufacturing of fused silica by combining ultrasonic vibration with fixed-abrasive pellets

Vibration-assisted grinding, in which harder abrasives than materials to be machined are employed, has been a viable and effective approach to increasing material removal rate (MRR) and/or reducing surface roughness of ground surfaces. We transfer this ideology to fused silica polishing by incorporating ultrasonic vibration into recently developed fixed-abrasive pellets in an attempt to enhance MRR and/or to improve manufactured surface quality. A prototype ultrasonic vibrator, the heart of the polishing head, was designed and the related experimental work was performed on an in-house built setup in conjunction with the constructed head. The vibrator is devised for the generation of 2-D tool path despite using only one actuator in lieu of two actuators in conventional 2-D ultrasonic machining systems. We then combined the ultrasonic vibration with fixed abrasive polishing pellets to machine fused silica glass. Machining experiments reveal that MRR is considerably increased up to >50% upon the introduction of ultrasonic vibration (UV) whilst surface roughness is not degraded appreciably. It was also noted that a overwhelmingly greater deal of polishing debris was dispelled during ultrasonic vibration assisted polishing than conventional bound-abrasive polishing, which may account for the greater MRR in UV assisted polishing.