Rotary Ultrasonic Grinding Research Articles

Study on the removal mechanism of Si3N4 ceramic material in rotary ultrasonic grinding based on multi-abrasive coupling simulation

Study on the removal mechanism of Si3N4 ceramic material in rotary ultrasonic grinding based on multi-abrasive coupling simulation

Development and characterization of a rotary ultrasonic grinding tool with large cup wheel for SiCp/Al composites

Development and characterization of a rotary ultrasonic grinding tool with large cup wheel for SiCp/Al composites

Experimental study of surface residual stress and hardness of TiBw mesh reinforced titanium matrix composites in rotary ultrasonic grinding

Experimental study of surface residual stress and hardness of TiBw mesh reinforced titanium matrix composites in rotary ultrasonic grinding

Simulation Study on Removal Mechanism of Si3N4 Ceramic in Rotary Ultrasonic Grinding

Simulation Study on Removal Mechanism of Si3N4 Ceramic in Rotary Ultrasonic Grinding

Design and characteristic investigation on straight grinding wheel tool holder with different bonds and abrasives for rotary ultrasonic grinding

Design and characteristic investigation on straight grinding wheel tool holder with different bonds and abrasives for rotary ultrasonic grinding

Study on wear simulation of diamond abrasive tool for rotary ultrasonic grinding

The aim of this study is to explore the wear mechanism of diamond grinding tools in rotary ultrasonic grinding process and complete the simulation study of micro wear state of diamond grinding tools in different processing stages. Primarily, the morphology of single diamond abrasive grains is analyzed and studied, and a three-dimensional irregular abrasive grain simulation is carried out according to the morphology characteristics of diamond abrasive grains. Then, the center distance and spatial distribution law between diamond grits are obtained by calculation, and the discrete three-dimensional morphology simulation of diamond abrasive end face is completed based on the virtual lattice theory. Through the rotary ultrasonic grinding experiment, the wear form of diamond grits and the mathematical model of the wear amount of diamond grits changing with the removal amount of workpiece material are determined. The wear simulation of diamond abrasive tool with different workpiece removal is completed by using the mathematical model obtained from experiments. Last section, the number of abrasive particles in the simulation model and the wear amount of the abrasive tool are compared and analyzed with the corresponding experimental results. The above research provides a new research method for exploring the wear mechanism of diamond abrasive tools.

Investigation of the longitudinal-flexural resonating spindle in ultrasound-assisted grinding of SiCp/Al composites

Rotary ultrasonic machining is a cost-effective and precise machining method for hard and brittle materials. Aiming at processing SiCp/Al composites, a rotary ultrasonic grinding spindle is proposed in the present study. Expressions were established to calculate the displacement, rotation angle, bending moment, and shear force of the vibrating elements based on the Mindlin moderately thick plate theory. Combining continuous and boundary conditions of vibrating elements with the proposed expressions, the vibration model and frequency equation of a longitudinal-flexural resonating transformer with a large load were established. Then two transformers were designed according to the frequency equation. The resonant characteristics of the transformers were studied using finite element analysis, impedance analysis, and ultrasonic resonance experiments. The obtained results show that the maximum deviation between the resonant frequency and the design frequency of the transformers was 4.95%. Moreover, the maximum deviation of the positions of the pitch circles was 6.51%. It is concluded that the proposed designs have high accuracy. Finally, the orthogonal single-factor experiments of SiCp/Al composites were performed with and without ultrasound. The obtained results show that introducing ultrasonic vibrations significantly reduces the grinding force and the surface roughness while improving the surface quality of the SiCp/Al workpiece. The present study is expected to provide experimental fundamentals to further improve the structure of the grinding spindle, optimize process variables of ultrasound-assisted grinding, and improve the processing efficiency.

Three dimensional shape model of TiBw mesh reinforced titanium matrix composites in rotary ultrasonic grinding

TiBw mesh reinforced titanium matrix composites have excellent mechanical properties and high temperature properties, which have a wide application prospect in aerospace and other fields. However, the material processing has the characteristics of poor surface quality and unstable processing. In order to solve these problems, Rotary ultrasonic grinding was carried out on machining titanium matrix composites in this paper. A surface topography model for rotary ultrasonic face grinding of titanium matrix composites was analyzed, in which the effects of the shape of the cut section of the abrasive grain, the plastic deformation of the material, and whiskers were considered to analyze the formation mechanism of the surface of titanium matrix composites machined by rotary ultrasonic machining. The reliability of the model is verified by comparing the simulated topography with the actual topography through grinding experiments.

Characteristic analysis of rotating ultrasonic machining applied in zirconia grinding

This research uses rotary ultrasonic grinding technology to grind zirconia (ZrO2) ceramic. The purpose is the optimization of processing parameters for rough and fine grinding. According to Taguchi method, optimized processing parameters will be available to find and successfully verified. The objective function of rough grinding is the material removal rate (MRR), and a maximum is expected. The processing parameters can be spindle speed, ultrasonic power, feedrate, and cutting depth. The best MRR is 192mm3/s in Taguchi’s experiment, and the optimized MRR is 2.14mm3/s, which can be increased by 1.11 times.Moreover, the objective function of fine grinding is surface roughness (Ra), which needs to find a minimum value. The control factors are spindle speed, ultrasonic power, feedrate, and the number of times of grinding. In the Taguchi experiment, the minimum roughness predicted by the fine grinding is Ra0.16, but the roughness is obtained Ra0.2 by the verification experiment. It may be that the effects of the factors are not completely independent, and there are interactions between them. The predicted value will not be completely correct via the superposition of each factor effect. It can also be found that the independence of the fine grinding speed, ultrasonic power and feed factor is not strong enough for the variation analysis. It affects the results of the prediction and confirmation experiment.

Study of Subsurface damage of tungsten alloy in rotary ultrasonic grinding

Study of Subsurface damage of tungsten alloy in rotary ultrasonic grinding

Investigation on grinding force and machining quality during rotary ultrasonic grinding deep-small hole of fluorophlogopite ceramics

Fluorophlogopite ceramics is widely used in the fields of aerospace and biomedicine, and the machining of deep-small hole for fluorophlogopite ceramics is a focus in the field of precision and ultra-precision machining. In this work, the trajectory and brittle-to-ductile transition depth of single abrasive during rotary ultrasonic grinding process were analyzed. The rotary ultrasonic grinding and common grinding tests of deep-small holes for fluorophlogopite ceramics were performed on an ultrasonic vibration and precision machining center. The axial grinding force was obtained by wavelet denoising, the roundness deviation was calculated by using Canny and gray level detection methods, and the internal surface roughness was measured by using laser scanning confocal microscopy. The experimental results indicated that compared with the common grinding, rotary ultrasonic grinding could effectively decrease the grinding force, roundness deviation, and the value of surface roughness. In addition, the grinding force, roundness deviation, and the value of surface roughness decreased as the spindle speed and ultrasonic power increased, and they increased as the feed speed increased. This work was of significance for realizing the high efficiency and precision machining of deep-small holes of the hard-brittle materials.

Study on key factors influencing the surface generation in rotary ultrasonic grinding for hard and brittle materials

Rotary ultrasonic grinding (RUG) provides effective solutions for hard and brittle materials processing, but the surface generating mechanism is still unclear. This paper presented a fundamental research for surface forming in RUG processing hard and brittle materials. A new method is pointed out for surface morphology regulating and predicting in engineering ceramics machining. According to the kinematics analysis and fracture mechanics of brittle materials, the surface forming model is developed step by step. The grinding force and material removal rate are discussed for evaluated the RUG process. Depend on the mathematical models, the dynamic association between ultrasonic energy, grinding parameters and surface micro structure were revealed and presented. The surface topography can be simulated and regulated by ultrasonic energy control or grinding parameters adjustment. Micro structure design and high precision machined surface can be realized through theory calculation. Due to the fundamental analysis, a series of simulation and experiment were executed for verify the theory deduction. This model can be served as a fundamental principle for surface topography modification and machining efficiency improvement in RUG.

Distributed capacitance effects on the transmission performance of contactless power transfer for rotary ultrasonic grinding

The contactless rotary transformer has been widely used in rotary ultrasonic machining because of less heat, less vibration, no friction and higher revolving speed. However, the power transfer efficiency of the rotary transformer is rather low. So it is necessary to adopt the method of capacitance compensation to maximum transfer efficiency, and more accurate compensation model will achieve better transmission performance. However, distributed capacitance existing in the primary and secondary winding current compensation models, which will seriously effect accuracy of capacitance compensation. In this study, a new mathematical model of four circuit compensation topologies is proposed, which takes distributed capacitance into consideration. Moreover, a series of experiments are conducted, which focus on the transmission efficiency and output power. The results of experiments have a good consistency with the new model and show higher accuracy compared with the previous models. In addition, the effect of distributed capacitance at different frequencies is also researched.

Effect of temperature and radial force on the transmission performance of contactless power transfer for rotary ultrasonic grinding

Rotary transformer has gradually become used in rotary ultrasonic machining device for power transmission. Compared with contact power transmission, such as slip ring, the contactless power transfer system makes it possible to transmit power without friction, abrasion, vibration and heat. However, in rotary ultrasonic grinding, the varieties of temperature and mechanical load will greatly impact the transmission performance of the contactless energy transfer circuit. This study presents a simple mathematical model of four circuit compensation topologies, which is applicable for non-ideal condition, and explores the transmission efficiency, output power, and voltage of compensation elements under different temperature and mechanical loads based on this model. The optimal compensation method for the rotary ultrasonic grinding is determined by comparison.

Investigation on surface morphology model of Si3N4 ceramics for rotary ultrasonic grinding machining based on the neural network

Si3N4 ceramics parts surface morphology is related with surface friction and wear properties directly. Poor surface morphology will result in friction coefficient increases, strength decreases, and even lead to component failures. In order to improve Si3N4 surface morphology, it is necessary to investigate on the relationship model between the surface morphology and process parameters. In the paper, rotary ultrasonic grinding machining (RUGM) was taken as object to establish the model based on back propagation (BP) neural network. However, the nonlinear relationship of the model is complex, and the traditional algorithm cannot realize satisfying results. So an improved BP neural network algorithm based on Powell method has been proposed. The paper gives the theory and calculation flow of the algorithm. It is found the algorithm can accelerate the iteration speed and improve iteration accuracy. The investigation results provide the support for surface morphology optimization.

Investigation on the surface morphology of Si3N4 ceramics by a new fractal dimension calculation method

Rotary ultrasonic grinding machining (RUGM) has been employed in Si3N4 ceramics parts machining widely, and the surface morphology is related with surface friction and wear properties directly. It is necessary to investigation on the surface morphology characterization to improve surface quality. Surface morphology of Si3N4 ceramics for rotary ultrasonic grinding machining was investigated based on fractal theory in the paper. The fractal features of surface morphology have been proved with qualitative and quantitative investigation. Differential box-counting method and peleg-blanket method was applied to calculate fractal dimension, but low calculation accuracy was found. So a new fractal dimension calculation method called perimeter-volume method has been proposed. The results show that the calculation deviation rate of morphology fractal dimension is only 2.5%. Meanwhile, the influence of spindle speed, cutting depth, feed rate and cutting force on fractal dimension has also been investigated. The investigation results provide the support for surface morphology optimization.

Power Transfer Performance and Cutting Force Effects of Contactless Energy Transfer System for Rotary Ultrasonic Grinding

In rotary ultrasonic grinding (RUG), a rotating transformer can be used to replace the established slip ring technology and provide a contactless power supply to the revolving transducer. Such contactless energy transfer (CET) is safe, and high rotation speeds are possible. Compared with a closely coupled transformer, the transfer efficiency of the rotating transformer is lower. Compensation of the windings is necessary to improve efficiency. In addition, the cutting force in RUG is not constant; this will influence the power transfer performance, which in turn affects the vibration amplitude of the tool. In this paper, by considering the distinct capacitive and mechanical behavior of the transducer and the equivalent series resistances (ESRs) of the compensation elements, mathematical models are developed to identify the transfer efficiency and the output power of the rotating transformer. A general mathematical compensation model is developed for maximum transfer efficiency. The effects of the cutting force on the transfer efficiency, the output power, and the power factor are also researched. The experimental results basically agree with the calculated results. A CET system that can produce high efficiency, a high power factor and adaptive output power that adapts to the variations of cutting force in the RUG is therefore possible.

Investigation on surface residual stress distribution and evaluation of engineering ceramics in rotary ultrasonic grinding machining

Residual stress of engineering ceramics is one of surface integrity evaluation indexes affecting the parts’ strength properties. Rotary ultrasonic grinding machining is the most powerful machining method for engineering ceramics with better surface integrity. The residual stress field distribution is changed due to micro cracks which are inevitable in the process. A residual stress distribution model of machined surface micro crack tip has been established in the paper. And the experimental results enable us to obtain surface residual stress distribution of engineering ceramics in rotary ultrasonic grinding machining. Then, we propose an evaluation parameter called confidence stress tolerance to evaluate surface residual stress characteristic. Preliminary results indicate that surface residual stress distribution is in line with the normal distribution. Confidence stress tolerance is an effective parameter to improve the evaluation reliability. Furthermore, precision and affecting factors of confidence stress tolerance evaluation have also been investigated.

Experimental investigation on rotary ultrasonic grinding machining surface morphology of Al<SUB align="right">2O<SUB align="right">3 ceramics based on fractal dimension

Rotary ultrasonic grinding machining (RUGM) can realise higher surface integrity for Al2O3 ceramics. However, the surface morphology characteristics is different from the metal materials due to material removal mechanism. Experimental investigation on RUGM surface morphology of Al2O3 was carried out. The shape self-similarity and statistical self-similarity were proved for RUGM surface morphology of Al2O3 ceramics through the experimental results analysis, so the surface morphology can be investigated with fractal dimension. The change rule and the relationship between fractal dimension surface morphology and the process parameters were also investigated. The experimental results indicate that the fractal dimension of grinding surface morphology is bigger than that of RUGM when the feed rate and grinding height change. Moreover, the fractal dimension is associated with cutting force. The cutting force is small while the fractal dimension is big, then the surface morphology is relatively complex, ups and downs variations of surface morphology are notable.

Investigation on surface roughness in rotary ultrasonic side grinding of SiCp/Al composites

SiCp/Al composites are widely used in many fields because of their outstanding mechanical and physical characteristics; however, they are difficult to machine owing to the reinforced particles in the matrix. In this work, the rotary ultrasonic side grinding experiments of SiCp/Al composites reinforced with 45% volume SiC particles were carried out to investigate the effects of the spindle speed, feeding speed, cutting depth and ultrasonic vibration amplitude on the surface roughness. The values of surface roughness have different change regularities with spindle speed and cutting depth in various intervals. The Ra values show a rising trend with increased feed rate and it is in line with the change of Ra in machining of ordinary metal materials. The varying pattern of Ra with the change of vibration amplitude is similar to ultrasonic-assisted grinding of other hard and brittle materials.