Ultrasonic Vibration System Research Articles

A Study on Erosion Performance of Monocrystalline Silicon in Ultrasonic Vibration-Assisted Abrasive Water Jet Machining

Ultrasonic vibration-assisted machining (UVAM) is an effective and promising technology for processing hard and brittle materials, it has been explored in many experimental and theoretical investigations. In this paper, a study on the erosion performance of monocrystalline silicon with UVAM is presented and discussed. In the erosion experiments, monocrystalline silicon wafers were eroded by the abrasive water jet machine assisted with an ultrasonic vibration system. A contrast experiment was carried out firstly to study the influence of the ultrasonic vibration, and then an orthogonal experiment investigation was carried out to understand the effect of process variables (the abrasive particle diameter, jet impact angle, standoff distance, abrasive mass flow rate and ultrasonic vibration power) on the depth of erosion and material removal rate (MRR). The experimental results revealed that ultrasonic vibration-assisted abrasive water jet erosion (UVA-AWJE) can obviously improve the depth of the erosion and MRR compared with those in traditional AWJE and the variation trends of the effect of the abrasive particle diameter, jet impact angle, standoff distance and abrasive mass flow rate on the erosion performance in UVA-AWJE are very similar to those effect in the traditional AWJ machining.

Effects of Laser Melting Treatment on Cavitation Erosion of 17-4PH Steel

Cavitation erosion behavior of 17-4PH steel used for large turbine blades and laser surface melting layer were investigated in simulated seawater 3.5%NaCl solution through an ultrasonic vibration system. The microstructure and the eroded surface and cross-section morphology were observed by SEM and OM, then the results were compared and analyzed. The results showed that the microstructures of 17-4PH stainless steels consist of martensitic matrix, ferrite and residual austenite. Compared with 17-4PH substrate, it found the microstructure of laser surface melting treatment became dense and homogenous, the microhardness increased 80HV. During cavitation test, the cavitation incubation period of laser surface melting sample raised 1 time than 17-4PH steel, and enhanced its cavitation resistance through fine grain strengthening.

The grinding wheels for ultrasonic assisted grinding with tool vibration

This article presents the grinding tools designed to serve hybrid machining process – ultrasonic wheel vibration assisted grinding. It describes possibilities of using of different abrasives, grinding wheel clamping systems and holders with ultrasonic oscillation inductor. Realization of Ultrasonic Assisted Grinding (UAG) process is possible on machines with special design. Most machine tools are manufactured on the basis of conventional ones and are retrofitted with ultrasonic vibration system. There are two types of tool holders designed for this machine tool: holders for hybrid machining processes (ultrasonic actors) and holders for conventional processes. Each type of tool holder is fixed to the spindle with hollow taper shank. The tools are attached to the ultrasonic actors by screw and positioned on arbor, or by the collets. For the UAG process tools made of various abrasives are applicable. Binding material, the concentration of abrasive grains and their size may differ. It is possible to use diamond or cubic boron nitride tools and also tools made of conventional abrasives. Ultrasonic Assisted Grinding is a novelty in the field of manufacturing techniques. It is necessary to conduct detailed investigations of this process. The factors that have a significant impact on the UAG results for different materials, the oscillatory motion parameters in relation tool or workpiece as well as on the dressing tool should be investigated.

Experimental Study on Laser Metal Deposition of FGMs with Ultrasonic Vibration

Referring to the ultrasonic vibration effect on casting, welding and laser cladding, the paper demonstrates the feasibility that it can be also used in Laser Metal Deposition(LMD)of titanium alloy to protect the defects such as crack,pore and oxidation and refine the grain size and improve the distribution uniformity of solidified structure.So the paper applies ultrasonic vibration system to fabricate the functionally graded materials(FGMs) samples and analyses its effect on the specimen microstructure and mechanical property by experiments.The results show that ultrasonic vibration can suppress the formation of pore、refine the grain and make the TiC hard phase more homogeneous in the FGMs parts, which is also indicated by the microhardness tests

Optimal Design and Test of Ultrasonic Vibration System

Ultrasonic vibration system is the chief component of USM machine tool. Whether products are precisely machined is lie on the performance of the system. To design good performance of ultrasonic vibration system, finite element method is used to analyse the dynamic performance of the system based on theoretic calculation. The dynamic performance of transformer and transformer with tool is analysed respectively, including natural vibration characteristic and harmonic characteristic. The result of FEA is compared with theoretic calculation. The parametric optimization design technique of the finite element analysis package ANSYS is applied to optimize the structure dimension of the piezoelectric transducer and transformer with tool. Then amplitude of the optimized system and the previous system is compared based on laser-CCD sensor for micro-displacement. The optimized system is more superior and has larger amplitude. Last some round holes are machined on kentanium YG8, monocrystalline silicon, PZT. And machining effect of single Micro-USM is got by the test.

Development of Handheld Ultrasonic Spot Welding Machines

As the resonance frequency of the ultrasonic vibration system drifts according to the different operating condition, Ultrasonic power supply based on MSP430 is designed in this thesis. Series inductance and parallel capacitance are used to match the vibration system and series resonance technology used in primary side of inverter transformer can reduce switch loss. ADC module in MSP430 is used to get frequency shift, and PWM module is made to adjust the operating frequency of TL494, which can realize closed loop control of frequency tracking. The results of experiments show that the method designed in this thesis has high detection accuracy, high speed dynamic response and high stability of frequency tracking.

Study of Acoustic System Characteristics of Ultrasonic Machining Based on Similarity Principle

Based on similarity principle, cutting modes of turning, milling, grinding etc are equivalent to three load forms of dot, line and face. And three different loads of dot, line and face are applied on the nano-ZrO2 workpiece by three different indenter models of dot, line and face. To one-dimensional ultrasonic vibration system, the influence is studied which is of different load forms and different load magnitudes on acoustic system characteristics of ultrasonic machining. The experimental results show that, the change of loads has little influence on the acoustic system parameters of ultrasonic machining when the load modes on the nano-ZrO2 workpiece are dot and line. And when the load mode is surface contact, the change of loads has significant influence on the acoustic system parameters of ultrasonic machining.

Design of the Amplitude Transformer in Ultrasonic Vibration System

The amplitude transformer is widely applied in ultrasonic machining because it can magnify the amplitude between the ultrasonic transducer and the tool. This paper explained the experimental device of the ultrasonic vibration system, the design principles of the amplitude transformer and the design process of the conical transformer. At last, it gave the engineering drawing of the amplitude transformer.

Key Factors Affecting the Amplitude of a Composite Ultrasonic Wiredrawing Vibration System

This paper studied the key factors affecting the amplitude of a composite ultrasonic wiredrawing vibration system, for designing a powerful ultrasonic vibration system. The finite element analysis (FEA) was performed. The results showed that the variable cross-section shapes of horns and the angles between the connection of both ends of the cross-section and the center line had great effects on the amplitude of an ultrasonic vibration system. In order to valid the theoretical result, the experiments were carried out on a composite ultrasonic vibration system. The experimental result demonstrated that the conical variable cross-section rods used in an ultrasonic vibration system produced large amplitude.

A High Efficient Variable Cross-Section Compound Ultrasonic Wiredrawing Vibration System

To solve the technical difficult problem of difficult-to-draw materials, this work presented a composite ultrasonic vibration system with variable cross-section rods. The four-terminal network method and the finite element method were used to design the conical, the exponential and the catenary transducers. The finite element results of show that the oval trajectory can effectively improve the friction effect between the wire and the tool head. The experimental result showed that the maximum amplitude was about 60 μm. It was 3 times of that in our previous work. These results demonstrated the design of the composite ultrasonic vibration system was feasible.

Developing a special block sonotrode for ultrasonic-assisted grinding process

Despite its known advantages, the ultrasonic-assisted machining process has not been widely introduced into industrial environment. Until the present time, the ultrasonic-assisted machining was only possible for small and light parts, when vibrating the workpiece, or for small and special designed tools, when vibrating the tool. It is demonstrated that due to the changes in mechanical properties of the material, efficiency of the ultrasonic assisted machining is much higher when the vibration is superimposed on the workpiece. Hence, there is an abundant need for development of a proper innovative ultrasonic vibration system which is able to vibrate industrial workpieces of different sizes and weights. To address this requirement, a special designed block sonotrode is invented. The first carried out experiments show that the application of the new ultrasonic system can reduce the grinding forces, surface roughness and thermal damages on the workpiece and increase the G-ratio considerably.

Ultrasonic vibration-assisted optical glass hot embossing process

A homemade apparatus was used to apply ultrasonic-vibration to assist the glass hot embossing processes. To operate at high temperatures for glass hot embossing, the ultrasonic vibration system was appropri- ately designed with an embedded cooling system, and an ultrasonic horn was specifically modified for high- temperature use. Molds with both V-groove and Fresnel structures were manufactured for hot embossing experi- ments on PSK-100 glass. The heights of the molded structures were increased significantly with the assistance of ultrasonic vibration. This technology demonstrates the capability to upgrade the performance of the glass hot embossing process.

Experimental Optimization of Deep Drawing Using Response Surface Methodology

A ultrasonic vibration system with ram motion of two steps is developed to optimize the formability for thin workpiece at the end of forming. The deep drawing force and forming height can be predicted in view of optimizing the values of the working variables involved in the process parameters. A response surface methodology (RSM) based on design of experiments was used in order to minimize the forming force and maximum the forming height during the deep drawing process. Associated plots are shown to be efficient for a quick choice of the optimum values of the forming process parameters.

Development of integrated precision vibration-assisted micro-engraving system

A novel precision vibration-assisted micro-engraving system was developed by the integration of fast tool servo and ultrasonic elliptical vibration system, in which the flexure hinge was designed to avoid backlash and PID control algorithm was established to guarantee specific precision. Apart from experimental validation of the performance of the system, various micro-V-grooves cutting experiments on aluminum alloy, ferrous material and hard cutting material were performed, in which Kistler force sensor was used to measure cutting force. Through experiments, it was clear that the vibration-assisted micro-engraving system can ensure good quality of micro-V-grooves and reduce cutting force by about 60% compared with traditional removal process without ultrasonic vibration.

Optimal Design of Rotary Ultrasonic Vibrator and Research on its Machining Experiments

In order to obtain well work performance, a new design process and the optimal method are systemically presented during ultrasonic vibrator’s design. Firstly, the general dimensions are calculated according to formula of ultrasonic theory. Secondly, 3D model without flange is established, and the best position setting a flange has been conformed through finite element analysis (FEM). Then constraints are laid on the flange, and the best model of vibration is obtained based on model analysis. The results are benefit to the following control design of ultrasonic vibrator. Finally, an ultrasonic vibration system has been made, and a series of experiments validate the feasibility of the design method.

Research on Ultrasonic Vibration Combined with Grinding Machining and its Application in Processing Brittle Hard Materials

A system of ultrasonic combined with grinding has been designed, and one novel connective method of straight screw combined with taper surface has been applied in spindle, so compact size and high revolving accuracy can be achieved. Modal analysis of ultrasonic vibration system has been implemented by FEM (Finite Element Method), and its optimal dimension has been calculated to find out optimal vibration estate. Full-bridge converter has been applied in driving circuit of ultrasonic vibrator, and auto-frequency tracking has been designed in order that ultrasonic vibration works on resonant or quasi-resonant frequency. Finally, machining experiments have been fulfilled about ultrasonic combined with grinding, and its machining effect has been distinctly improved comparing ordinary grinding machining.

Experimental Research on the Vibration Characteristics of Flexural Vibration Disk

The vibration characteristics of flexural vibration disk in ultrasonic vibration system are studied through experiments. The results show that the resonant frequency of flexural vibration disk reduces with the reducing of its thickness and the resonant frequency increases with the reducing of its diameter. When designing the ultrasonic vibration system, because the transformer horn and the flexural vibration disk are designedly integrated, the defects caused by the way of threaded connection can be avoided. It is found that flexural vibration is dominating in the disk with some reflected ultrasonic through experiments, at the same time, there exist amplifying characteristics in the vibration of the disk and the maximal amplitude can reach 18 μm. The corresponding results provide certain reference value for the structure design of ultrasonic vibration system and the application in ultrasonic vibration deep-hole honing.

Effects of the Edm Combined Ultrasonic Vibration on the Machining Properties of Si<SUB>3</SUB>N<SUB>4</SUB>

The authors have previously performed numerous experiments on the machining of insulating materials using the assisting electrode method. However, the machining performance was inferior to that of the electrically conductive materials. To overcome this inferiority, for this research, an ultrasonic vibration system was combined with electrical discharge machining (USEDM) and applied with the assisting electrode method. Rotational machining was also added. A cylindrical copper tungsten bar was used as the electrode material for machining the sintered Si3N4 insulating ceramic. The effects of the electrode polarities, the effects of the amplitude on machining performance, the generation of a conductive layer and the discharge waveforms were investigated. The results were then compared to the conventional electrical discharge machining (normal EDM). The finishing process was performed by combining the ultrasonic vibration and various abrasive suspensions to remove the conductive layers and the craters. The results show that the material removal rate improved by a factor of approximately two over the normal EDM, and the surface roughness increased when the ultrasonic vibration was applied. The conductive layers and the craters were removed by the ultrasonic vibration using an abrasive (US+abrasive) method. The surface roughness of the workpiece was greatly improved by using the proposed method.

Research and Development of Ultrasonic Honing Vibration CAE System on UG

With a more application of ultrasonic technology, power-ultrasonic applied in the filed of processing about rare earth alloy and magnesium-aluminum alloy, which become more and more widespread. A steady and efficient ultrasonic vibration system is crucial, so it’s important and superior to research on the parameterization and modularization about the ultrasonic vibration system. The paper, based on the UG platform, researched and developed the modular power supersonic resonance CAE system with the using of the UG re-development tool and VC++. Finally it indicated the design method is reasonable through the confirmation of ultrasonic vibration experiment, which has a bright prospect in application.

Design of Ultrasonic Transformer Vibrated Radically with Double Supports in Gear Honing

Ultrasonic vibration can reduce honing forces efficiently. As the honing wheel can be washed by ultrasonic cavitations of cooling liquid, its jams are decreased and the higher honing efficiency has obtained. Therefore, the combination of ultrasonic machining and gear honing is a method for gear fine machining with its wide application future. In the paper, to improve the rigidity, the ultrasonic vibration system adopted the structure of double supports as traditional honing machine, so the horn is symmetric. The machined gear was simplified into a circular thin plate with diameter of its reference circle and the horn was treated as its half as the symmetry; the frequency equations of the transformer were derived according to stress match under the condition that the half horn and plate of the transformer were considered at the same time; the frequency equations were derived based on the boundary conditions. Then the design parameters of the transformer were obtained as the frequency equation was solved computationally and expanded to the whole horn. The displacement, stress of the transformer was solved, too. Finally, the vibration mode of the transformer was analyzed by ANSYS. The results of theoretical and ANSYS analysis is consistent, which means the theoretical model and analysis method are correct.