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The existing contactless energy transfer of rotary ultrasonic machining equipment involves a small transmission distance (0.1-1 mm). In this research, magnetically coupled resonant wireless power transfer was used in rotary ultrasonic machining process. A series of theoretical models were established to explore the transmission characteristics of the system, and experiments were carried out to verify transmission characteristics.

In this paper, two kinds of ultrasonic milling systems, the axial vibration of the tool and the horizontal vibration of the workpiece, were designed, built, and tested. Then taking TC4 titanium alloy as the research object, the ultrasonic machining system was used to carry out milling of titanium alloy, and the influence of different vibration directions on tool wear and surface morphology characteristics was obtained. The results show that the deviation between the designed vibration system and the theoretical value is small, and the test results are good. Then, the experimental analysis showed that when the same volume of titanium alloy material was removed under the two vibration modes, the tool vibration can reduce the tool wear compared with the workpiece vibration, no matter in terms of the wear amount of the rear tool face, or in terms of the bonding wear and oxidation wear. It is found that the root cause of surface micro-texture was the periodic change of cutting depth, and the application of axial vibration was more conducive to the generation of micro-texture than the horizontal vibration of workpiece.

An IoT ultrasonic generator for the ultrasonic machining system is studied and developed. We used an embedded system to construct an IoT node. The embedded system controls a switch-amplifier that amplifies the power for alternating current excitation signal. The system realizes the functions of frequency sweep, lock, and tracking through the phase angle and the current signal feedback. The experiment results show the IoT ultrasonic generator can monitor the system, remote control, record the current and the phase angle. Moreover, this equipment has automated and smart manufacturing with promising potential for further improvement makes the designed circuit suitable for future practical applications.

The paper describes design, modeling and control of a five-axis monolithic nanopositioning stage constructed from a bimorph piezoelectric sheet. In this design, actuators are created by removing parts of the sheet using ultrasonic machining. The constructed nanopositioner is ultra-compact with a thickness of 1 mm. It has a X and Y travel range of 15.5 µm and 13.2 µm respectively; a Z travel range of 26 µm; and a rotational motion about the X- and Y-axis of 600 µrad and 884 µrad respectively. The first resonance frequency occurs at 883 Hz in the Z-axis, and the second and third resonance frequency appears at 1850 Hz, rotating about the X- and Y-axis. A decentralized control strategy is implemented to track Z, θx and θ y motions. The controller provides good tracking and significantly reduces cross-coupling motions among the three degrees-of-freedom.

Due to low density, very thin cell walls and hexagonal cell structure, nomex honeycomb composites are considered as difficult to machine materials. CNC machining is the most common method used for the cutting of nomex honeycomb composites but required machining qualities of the nomex honeycomb composites components are not satisfactory due to various machining defects. Therefore, a new nontraditional machining technology rotary ultrasonic machining has been introduced to overcome the machining problems of nomex honeycomb composites because of intermittent contact of cutting tool with workpiece, low cutting force and better machining quality. In this research, a novel Ultrasonic Circular Saw Blade (UCSB) cutting tool and Ultrasonic Circular Knife (UCK) Cutting Tool are introduced and designed for ultrasonic machining of nomex honeycomb composites. Impact of different structural parameters of UCK and UCSB cutting tools on resonant frequency is investigated by FE simulations modal analysis technique on ANSYS workbench. Designs of cutting tools are verified by comparing FE simulations with experimental results and it showed that the resonant frequency and amplitude of cutting tools are good enough to perform rotary ultrasonic machining of nomex honeycomb composites.

Pressure sensors working at high temperatures of $500 ^{\circ}C$ are required in various fields like aerospace, automobile and many industries. However, reliable sensors working at such high temperature are still not sufficiently developed. Mainly, developing a high temperature stable package imposes new challenges due to thermal cross-sensitivity and temperature induced stresses. Other major issues are to identify stable materials for high temperatures and stress-tolerant sensor mounting techniques. This research work focuses on the implementation of a stress-tolerant pressure sensor design for applications up to $500 ^{\circ}C$: A micro strain gauge is deposited and patterned on a Langasite (LGS) crystal. It is attached to a ceramic substrate Al 2 O 3 like a cantilever by flip-chip interconnection and glass solder underfill. The flip-chip bonding is done using gold stud bumps. The ceramic substrate has a membrane structure which is fabricated by ultrasonic machining. The deflection of the deforming membrane will be transferred pointwise to the free end of the crystal inside the package. The strain induced on the cantilever is measured by the change of resistance of a microstrain gauge. This special design concept aims at the elimination of thermal stresses between membrane and sensing device, which could induce cross-sensitivity. In this paper, processes to develop the complete assembly are presented including the choice of materials and fabrication methodology for individual parts. The resulting sensor package is stable for operations up to $500 ^{\circ}C$.

Ultrasonic machining is a hybrid machining process which combination of the additional rotary and ultrasonic vibration energy. It has been successfully applied in hard and brittle materials processing. In the ultrasonic processing application, the vibration energy will be different in the same driving current under the conditions of different parameters of the transducer. This paper proposes a method to predict the driving current using Elman neural network. According to the different parameters of the transducer, the different driving current required by the same vibration energy is obtained by the Elman neural network prediction model. A number of experimental data have been collected to be used by training the network model. Training results and predictive results show that it can be well adjusted by the driving current to obtain the same vibration energy and further to get the stable ultrasonic energy.

This study used the dynamometer to capture the force signal during ultrasonic machining, and the Empirical Mode Decomposition (EMD) was applied to analyze the vibration mode, including cavitation, impact and hammer effect. After capturing the characteristics of the vibration mode, such as marginal spectrum, mean frequency and energy, we established a measurement mechanism which could identify the stability of machining process and monitor the workpiece quality by cutting force signal. In order to enhance the design accuracy, we apply modal analysis and harmonic analysis for the ultrasonic horn design.

A design method for ultrasonic torsional transducer is presented based on the one-dimensional wave equation and the equivalent circuit method. Firstly, the equivalent circuits of torsional transducer and horn are constructed. The mounting flange can be placed right at the nodal plane, where no angular displacement occurs. An ultrasonic torsional tool is fabricated according to the presented method, and the resonance frequency and torsional vibration amplitude are measured by Laser. The comparison between the measured and predicted results shows that the present method is reliable, simple and straight.

Carbon fiber reinforced polymers (CFRP), have got rapidly enhanced applications in aerospace and other fields due to their attractive properties of high specific strength, high specific stiffness, and low thermal expansion. However, their properties like inhomogeneous, anisotropy and low heat dissipation are the main hindrance for machining of such materials with desired quality. In this research, the feasibility analysis was carried out and found that ultrasonic machining is only feasible for CFRP-T700 with low an elastic modulus of 233MPa as compared to rotary ultrasonic machining. Analysis of variance was performed and found that spindle speed is the significant parameter for feed and axial direction cutting forces. The cutting depth has found as a significant parameter for axial and feed cutting forces whereas the feed rate found a significant parameter for the axial force only. The optimal combination of these three forces has investigated with spindle speed 5000 rpm, feed rate 175mm/min and cutting depth 1.0 mm. Further analysis showed that spindle speed and cutting depth are significant for surface roughness and the optimal values for surface roughness (less than 1.5 µm) can be found with spindle speed 3800 rpm, feed rate 220 mm/min and cutting depth 2.2 mm cutting depth. The analytical model for surface roughness has then developed and validated. The results will be much helpful for machining of slots based on ultrasonic technology also for the industry level for better quality and to save expensive CFRP materials.

This article describes the design, fabrication and testing of a new XY nanopositioning stage constructed from a single sheet of piezoelectric material. The approach involves direct ultrasonic machining of a piezoelectric sheet to create flexural and actuator features. An industrial inkjet printer is then used to create electrode features by printing Nitric Acid directly onto the evaporated metal surface of the piezo sheet. The result is a monolithic piezoelectric structure with individual electrical control over each actuator feature. Experimental results demonstrate a full-scale range of 9 μm in the X and Y axes, and a first resonance frequency of 230 Hz in the Z axes. The completed nanopositioner is the thinnest yet reported with a thickness of only 500 μm. The new design method will enable a new range of ultra-compact applications in scanning probe microscopy, scanning electron microscopy, and active optics.

Ultrasonic machining is using a combination of ultrasonic longitudinal vibration and abrasive slurry. Ultrasonic machining is effective for machining in brittle materials such as ceramic materials. However, conventional ultrasonic machining methods use only longitudinal vibration. The few studies have investigated ultrasonic machining using combinations of complex vibration and abrasive slurry. In this context, we have developed a new method using abrasive slurry together with an ultrasonic complex vibration which produces longitudinal and torsional vibration for machining of brittle materials. Ultrasonic machining using complex vibration is expected to improve both machining time and accuracy as compared with longitudinal vibration machining. In this study, soda-lime glass is used as the material processed using complex and longitudinal ultrasonic vibration, and the results of measuring the hole machining characteristics show that ultrasonic complex vibration shortens the machining time and provides high machining accuracy.

For the current problems of resent ultrasonic machining driver, for example, output power is single and power regulation is not precise. This paper presents a new type of ultrasonic machining driver based on BUCK DC chopper. The new type of ultrasonic machining driver consists of STM32F106, DDS waveform generating circuit, signal processing circuit and the most important circuit which is BUCK DC chopper circuit. Principle of the power regulation, transmission's efficiency, the working principle and operating characteristic under current continuous mode of BUCK DC chopper circuit are established in this paper. The parameters related to BUCK DC chopper circuit are calculated. The system of ultrasonic machining driver is simulated by Matlab and related experiments of the driver were carried out. The experiments results show that the driver of new type based on DC chopper can achieved the expect function.

Ultraprecision micromachining of hardened steel with a single point diamond tool, which is practically impossible due to rapid tool wear, is realized by applying elliptical vibration cutting technology which has been developed by the authors. A practical ultrasonic elliptical vibration cutting system is developed in the present research, which consists of a practical vibration control system and an ultraprecision planning machine. The control system is fabricated to keep the elliptical vibration to have a desired locus, where the amplitudes of the two directional vibrations and their phase shift are kept to be desired values, and the vibration frequency is locked to an average value of their resonant frequencies. The vibration control system is mounted on the on the ultraprecision planning machine, which consists of three feed tables with double hydrostatic oil guideways in XYZ axes, two rotary index tables in BC axes and a five axis control system. The developed elliptical vibration cutting system is applied to ultraprecision diamond planning of hardened die steel, and a high quality mirror surface is obtained over a large area of the whole finished surface. Maximum roughness of the finished surface is less than 0.04 /spl mu/m Ry, although the cutting distance reaches 1110 m. On the other hand, the surface finished by ordinary cutting without the vibration, is cloudy with maximum roughness of more than 0.52 /spl mu/m Ry, within a cutting distance of 1 m. Based on this advantage, the elliptical vibration cutting system is successfully applied to ultraprecision micromachining of dies for a front light panel of LCD. An optical quality surface with fine microgrooves over a large area of 122 /spl times/ 91 mm/sup 2/ and with surface roughness of less than 0.04 /spl mu/m Ry is obtained by the developed system, which is difficult for any conventional machining methods including grinding, polishing and ordinary cutting.

This paper presents the design and characterization of a high resolution micro ultrasonic machining (HR-μUSM) process suitable for post-fabrication trimming of 3-D microstructures made from fused silica and other materials. The process targets low machining rates, high resolution, and high surface quality. On flat fused silica substrates, the process achieves machining rates ≤10 nm/sec averaged over 1 minute. The average surface roughness (Sa) achieved is ≤30 nm. The process is successfully demonstrated for trimming hemispherical 3-D microstructures made from fused silica.

Tungsten based MEMS devices have the potential to be used for many applications, such as tools for micro electrical discharge machining and ultrasonic machining, or mold for inject molding. For the first time, bulk tungsten inductively coupled plasma (ICP) etching was developed and characterized, which is capable of producing high aspect ratio (>13) structures with feature size below 3μm. Etching depth of 230μm has been achieved at an etch rate up to 2.2μm/min. This technology offers big opportunities for MEMS applications.

To optimize the traditional energy transmission where the slip ring abrades quickly and the spindle speed is not high enough in the rotary ultrasonic machining, the research is conducted on the non-contact power transmission system. Based on the principle of electromagnetic induction and Maxwell platform, the theoretical and the related simulation models of the mutual inductance of the non-contact power transmission system are established. A rotary electromagnetic coupling mechanism is then set up to verify those models. Through the simulation modeling and experiment verifying, the influencing factors on the transfer efficiency, such as the rotation speed, inter-stage magnetic gap, the ultrasonic frequency and resonance matching parameters have been investigated. As a result, the transfer efficiency at a high rotary speed can reach 80%, which provided a reference for the optimal design of the ultrasonic spindle.

Using two pieces of piezoelectric ceramics, a two-stage energy harvester for an application of micro Ultrasonic Electrical Discharge Machining (UEDM) is developed in this article. Ceramics in the first stage (PZT#1) plays the role of actuator driven with oscillation of high frequency and amplitude. In the second stage (PZT#2), the ceramics receives part of the power transmitted from the actuator in the first stage and generates electricity of satisfactory voltage and current for the application requirement. Modeling of the practical system with implementation of springs in between and outside of the ceramics and the weight ratio of the two ceramics in order to enhance durability in operation and gain better performance is investigated.

In grinding applications the processing of hard ceramics can be improved, if an ultrasonic axial vibration is superimposed to the rotation of the grinding tool in the grinding spindle head. The ultrasonic vibration is generated with a piezoelectric transducer which is attached to the rotating part of the spindle. Usually, the electrical energy is transferred with a rotary transformer consisting of a rotating secondary and stationary primary winding. There, the design of the rotary transformer is very crucial, since the available space in the spindle is limited and the cooling of the transformer is difficult. In addition, for high-speed applications the mechanical stresses on the transformer are high. Therefore, in this paper an optimization procedure of the rotary transformer with respect to minimum losses is presented, where magnetic, electrical and mechanical constraints are considered. In general, for a robust operation of the ultrasonic system an LLCC-filter is inserted between the piezoelectric transducer and the power converter, which makes the system insensitive to thermal and mechanical parameter variations. In order to keep the system complexity low, the needed LLCC-filter is magnetically integrated into the rotary transformer. In the literature, typically the components of the LLCC-filter are selected in such a way that the resonances of the LLCC-filter are matched to the mechanical resonant frequency of the piezoelectric transducer. This filter design method, however, doesn't result in minimum transformer losses. Therefore, in this paper also a new design method is proposed, which results in minimum transformer losses while keeping the ultrasonic system behavior stable and the control scheme simple. With a built prototype the proposed optimization procedure is experimentally verified based on a calorimetric measurement setup.

Two-dimensional ultrasonically assisted grinding technique is proposed to achieve a high material removal rate and high surface quality simultaneously. In this technique, the work-piece is attached on the ultrasonic vibrator produced by bonding a PZT device on a metal elastic body, and the elliptic vibration is generated by the simultaneous creation of the longitudinal and bending vibration of the vibrator. The grinding experiments are carried out and experimental results show that the surface quality is improved that anticipate your paper as one part of the entire proceedings, and not as an independent document. Please do not revise any of the current designations.

Ceramic materials, in comparison with metals, have many advantageous properties. Ultrasonic longitudinal vibration is currently used in combination with polishing slurry as an effective method for machining holes in brittle materials. However, this method suffers from the disadvantages of low removal rate and low machining accuracy. We aim to resolve these issues by using ultrasonic longitudinal-torsional (complex) vibration. In this study, soda-lime glass is used as the processed material in both ultrasonic longitudinal and complex vibration, and the machining time is measured to assess the hole machining characteristics. The results demonstrate that ultrasonic complex vibration shortens the machining time.

In this paper the rotating ultrasonic drilling is discussed as a new machining method to machine micro hole. It considerably improved the problems such as low entering drilling positioning accuracy, inferior hole dimensional accuracy and surface quality in current machining method. The machining characteristics discussed further proved the important meaning of the research of ultrasonic drilling. Due to the rotating movement introduced in ultrasonic drilling, there are many new technologies that are worth to study. This paper mainly discussed how the important component in ultrasonic drilling, the composite horn achieves resonance under different vibration sources of longitudinal vibration and torsional vibration, through which better machining effect and energy usage can be achieved.

The article is devoted to development of specified ultrasonic equipment for specifically drilling of fragile and very hard materials.

Grinding method is an effective way to process hard and brittle materials, such as ceramics. However, it is necessary to control the grinding force to achieve the desired surface quality and dimensional precision of ceramics parts. In this paper, we present the study results of the influence of machining parameters on the grinding force and its influence on machining performance such as machining speed and surface roughness. To improve machining efficiency and surface quality, the grinding process is aided with ultrasonic vibration. To control the grinding force, the fuzzy control strategy is used in this study. The effect of grinding force control on stability is studied. It has been found that the machining process is more stable with ultrasonic vibration than that without it. Ultrasonic vibration enhances machining speed and surface quality.

A lot of cutting fluid in metal cutting process causes environmental pollution and increases the manufacturing cost. Control of cutting fluid is one of the serious problems that the modern manufacturing technology faces with. This paper describes in brief the development tendency of cutting fluid and its limitations. The mechanism about pulse waveform generated by ultrasonic vibration cutter is studied, and experiments have been carried out by using of dry cutting. The experimental results indicate that the cutting temperature is close to room temperature, and the tool wear is lower. Dry cutting without cutting fluid is the real sense green cutting technique.

This paper reports a method for integrating and micromachining spherical structures made from materials such as fused quartz that are not amenable to melting or reflow. The 3D-SOULE process combines batch-mode micro ultrasonic machining (µUSM), lapping, and micro electro-discharge machining (µEDM) for creating spherical structures. Micro electro discharge machining is used for creating the stainless steel tool, which is then used for µUSM of the glass spheres. Stainless steel 440 which provides tool wear

The principle of Ultrasonic vibration assisted electrical discharge machining in gas medium (UEDM in gas) was proposed in this work and experimental equipment was designed. Hard and brittle materials such as cemented carbide and sintered Nd-Fe-B magnetic materials were machined using the experimental equipment of UEDM in gas. The thermal stress removal mechanisms of hard and brittle materials machined by UEDM in gas medium were discussed in detail. The process of thermal stress removal during UEDM in gas can be divided four steps, which are the formation of thermal stress, the formation of micro cracks, grain breaks and particles strips.

In this paper, the experimental research on the tool failure mechanism using YG6 and PCD tool cutting Particular Reinforced Metal Matrix Composites?PRMMCs? with ultrasonic cutting and common cutting was carried out, and it was discovered that: (1) the tool wear of ultrasonic cutting is less than that of common cutting, the cutting speed and feed speed have greater effect on tool wear and the cutting depth has little effect on it, the tool wear decreases with the increase of cutting speed and feed speed, and with the reduction of cutting depth, (2) the wear of PCD tool is about 1/10 of YG6’s with ultrasonic cutting the same distance, this is very similar to common cutting, (3) the modality of tool wear mainly shows the rake face wear, the flank wear and the tool breakage. When the distance of the cutting is short, the crater wear is not obvious on the rake face of YG6 tool, and the flank wear appears reverse triangle near the tip of tool under the two cutting ways. The PCD tool find no significant wear, but a serious tipping, (4) the tool wear of ultrasonic cutting is mainly abrasive wear, but it is weaker than that of common cutting, this is an important reason why the ultrasonic cutting can reduce the tool wear.

In the present paper, fuzzy-scale-based multiple attribute decision making (MADM-TOPSIS) method has been reported to rank five different alternative finishing processes for an internal cylindrical surface through systematic multi-attribute based evaluation. The mathematical procedure yields a suitability index which is used to rank finishing processes. The present TOPSIS-MADM method indicates that the honing process is the most suitable finishing process for the internal cylindrical surfaces whereas on the other hand, the processes like ultra sonic machining and abrasive flow machining are not desirable when they are to be considered for finishing an internal cylindrical surface.

Electrical discharge machining (EDM) is widely used for manufacturing various kinds of dies and molds. While it can bring some disadvantages such as environmental pollution. EDM in gas is a new technology and based on which a new EDM method called ultrasonic vibration assisted EDM in gas medium is proposed in this paper. The principle of ultrasonic vibration assisted electrical discharge machining in gas medium was introduced in this work and relevant experimental equipment was designed by which a serious of experiments was carried out. The model of MRR (material remove rate) taking the effect of ultrasonic cavitation during ultrasonic vibration assisted electrical discharge machining in gas medium was deduced. Experimental results showed that the MRR increases with the increase of peak discharge voltage, discharge pulse-on time, discharge peak current and gas pressure, but decreases with the increase of pulse-off time, which accord with the model of MRR.

The paper studies the silicon carbide particular reinforced aluminum matrix composites (SiC p /Al) and aluminum used YG6 and PCD tool in ultrasonic cutting and common cutting by a series of turning experiment. The results show that the machined surface morphology is different significantly with different cutting methods or different tools. The crush of groove edge is less and the surface is abound with ultrasonic vibration chatter in ultrasonic cutting SiC p /Al composites. The machined surface exists the abrasion grooves of aluminum matrix, pushed things, pits and other defects, and the crush of groove edge is more in common cutting SiC p /Al composites. The surface defects cutting by PCD tool is fewer significantly than the surface of cutting by YG6 tool. The surface used YG6 tool ultrasonic cutting aluminum appears uniform mesh chatter, the grooves are rules, and the edge of groove has not broken; while the surface used YG6 tool ultrasonic cutting SiC p /Al composites is uneven groove, relatively, the edge of groove has broken and the surface is rough, but the surface quality is better than that of common cutting.

The mode of the maximal undeformed chip thickness was constructed at the condition of small grinding wheel, big cutting depth and creep feed. Comparative experiments of grinding ZrO 2 ceramics with/without ultrasonic vibration were carried out,circular arc grooves were machined on ZrO 2 ceramics block. The experimental results have shown that ultrasonic vibration can descrease grinding force, ZrO 2 Ceramics can be machined with more process remaining by means of creep feed ultrasonic grinding.

This paper describes recent advances in batch-mode micro ultrasonic machining (μUSM) and its application to quartz crystal (QC) microstructures. Acoustic emission sensors are used for close monitoring of this batch process. Multi-level AT-cut QC microstructures have been successfully fabricated at a cutting rate ≫24 µm/min, which is substantially faster than available options for plasma-based etching. Arrays of disks, H-shaped and tuning fork structures are demonstrated with a cutting depth up to ∼105 µm on the 110 µm-thick QC substrate. Micromachined QC structures are also mounted on interconnection substrates. Preliminary electrical tests have been performed for resonance characteristics. A low-thermal-expansion glass ceramic, ZERODUR®, has also been micromachined at a cutting rate ≫18 µm/min.

Electric discharge machining (EDM) aided tool vibration is an effective method for some certain materials. In the practical machining process, the timely elevation of the tool electrode is needed to eliminate chipping. In this paper, an adaptive fuzzy control system of a servomechanism for EDM combined with ultrasonic vibration is studied. This control system can adjust the discharge pulse parameters timely and the gap between the tool electrode and the workpiece material, therefore, the machining state can be optimal, by which the EDM aided tool ultrasonic vibration is improved and the machining efficiency is increased.

In ultrasonic drilling, cutting and welding applications, ultrasonic devices are needed to generate large vibration velocities. It is renowned that whilst these devices are driven at high power their dynamic behaviour tends to exhibit nonlinear features. Until a fundamental understanding of this behaviour will not be achieved, and effective ways to control it developed, high power ultrasonics will unlikely find utilize in large scale industrial processes. This study is focused on the characterisation of the nonlinear behaviour of two power ultrasonic devices designed for rock drilling.

Nasa funded studies have proven that ultrasonics is a viable technology for extraterrestrial drilling. Previous research by the authors has indicated that ultrasonic longitudinal-torsional coupled vibrations may improve rock excavation. In this study, two approaches to the development of torsional output from a Langevin transducer are pursued: coupling the longitudinal mode with a torsional mode and degenerating the longitudinal mode to output torsional motion at the tip using helical flutes cut into the sides of the horn. The amplitude of the output motion and the electrical properties of the horn whilst these modes are being driven are investigated and the findings are validated experimentally.

When using diamond tool to cut the special stainless steel, the influence of cutting parameters on machining surface roughness is so great. Experiments of cutting special stainless steel by ultrasonic vibration were taken to develop the law that cutting parameters influence on surface roughness of the work piece. The relation curves between cutting parameters and the work piece surface roughness were achieved by contrast experiments with different cutting speed, tool feeds, cutting depth and vibration parameters. The result shows that cutting parameters have an obvious effect on surface roughness. Under given Conditions, the smaller amplitude of the vibration, the worse the surface roughness, and the higher vibrating frequency, the better surface roughness, and the more cutting depth and feeds, the worse surface roughness. Among these parameters, tool feeds was main effect on the surface roughness.

Based on mechanical kinetics theory, the torsional vibration equation of Twist drill is built and solved. Then, according to the characteristics of axial vibration drilling, its torsional vibration performance is analyzed deeply. The result shows that the average torsional deformation of low-frequency axial vibration drilling is less than that of common drilling and the torsional deformation of ultrasonic axial vibration drilling is approach to zero, so vibration drilling has a better surface quality and tool life than common drilling.

Braid wires are flexible and vibration-proof, and used widely for connecting various electrical equipments including battery earth wire and various electrical equipments. Braid wire end is usually connected using a solder or solderless terminal, and connected to the equipment by fixing bolts. Direct machining of terminal part of flat braided wire using a 20 kHz ultrasonic complex vibration is studied and rigid terminals are obtained. Using conventional linear vibration system, rigid terminals could not obtained.

Longitudinal to transverse vibration converters using different velocity metal-ring-pair with slanted thickness are proposed. Using the metal-ring-pair, complex vibration with no normal vibration component is obtained which is adequate for ultrasonic welding of semiconductor flip-tip bonding with large number of bonding pads, and also welding of large area specimens. And also, ultrasonic motor and rotating complex vibration machining tool are obtained using two metal-ring-pairs installed in a right angle.

Micro-machining is a delicate process that requires pinpoint accuracy. Researchers in academia and industry worldwide are striving to develop efficient fabrication techniques for features in ranges of a few micrometers and even nanometers. The current leading micro-machining processes are micro drilling, micro milling, and micro turning, micro EDM, micro USM, micro LBM, micro ECM and LIGA. In this paper, the latest advances of diverse micromachining technologies will be discussed. Challenges still exist in fields like innovation in workpiece and tool material, development of auxiliary tooling equipment together with processes combination, etc.

This article is devoted to analysis of different variants intersaw spacers for the ultrasonic gang saw. The influence on longitudinal and bending oscillations of saw blades is shown. The optimum design which secures saw blades resistance to fractures and necessary amplitude of oscillations is offered.

'Ultrasonic elliptical vibration cutting' technology, which has been developed by the authors, is applied to ultraprecision machining of single crystal germanium in the present research. The germanium is an excellent material for infrared optical devices, whereas ultraprecision micro-machining of the germanium is difficult due to its brittleness. Micro grooving experiments are carried out on the (100), (110) and (111) surfaces of single crystal germanium substrates, and basic effects of the elliptical vibration on the ductile micro-machining are clarified as follows. Critical depth of cut to generate a completely fracture-free surface on the single crystal germanium is increased significantly in all crystal orientations on the (100) and (111) surfaces, and ultraprecision micro grooving is realized successfully at a large depth of cut of 1 mum by applying the elliptical vibration cutting. This improvement by the elliptical vibration cutting is considered to be caused by reduction of instantaneous uncut chip thickness and cutting force in each cycle of the elliptical vibration. When the rake angle becomes negative, influence of the crystal orientation on the critical depth of cut becomes negligible, while it is considerable at 0 degree. On the other hand, the rake angle does not have considerable influence on average values of the critical depth of cut between -20 to 0 degree. The critical depth of cut is increased in all crystal orientations as the cutting speed is reduced in the elliptical vibration cutting