Electrorheological Fluid-assisted Polishing Research Articles

Ultra‐Precision Processing of Conductive Materials via Electrorheological Fluid‐Assisted Polishing

Ultra‐precision polishing of conductive components of novel electronic and optical devices at small scales is of paramount importance for achieving desired product performance and quality. Herein, the feasibility and performance of the electrorheological fluid‐assisted polishing (ERFP) approach in processing conductive materials are theoretically and experimentally investigated. The combination models for ERFP fluid with various size ratios of the polarized particles are established and discussed. A theoretical model for calculating the material removal volume in the ERFP process is derived to predict the polishing performance and the surface profile of the specimens. The measured material removal profiles agree well with the theoretical predictions, confirming the effectiveness of the proposed model. Experimental results demonstrate that the removal volume decreases rapidly with the increasing gap size and the rotation speed. With a microneedle‐like tool electrode, the ERFP is able to removal the material in a well‐controlled way, demonstrating its ability to polish conductive materials with high resolution and accuracy.

Experimental Investigation into Electrorheological Fluid-Assisted Polishing of Glass-Ceramic

A series of experiments are conducted to polish glass-ceramic by a circular-type integrated electrode tool in the electrorheological(ER) fluid-assisted polishing process. In this study, the microstructure of fibrous columns formed by particles perpendicular to the electrodes is observed when the electrical field is applied. The mass of ER polishing fluid gathered on the tip of tool electrode and the normal pressure in polishing area are measured by the dynamometer. The influential regularities of the concentrations of abrasive particles, the applied voltage, the spindle rotational speed, mixing ratio for abrasives and the gap between tool electrode and workpiece on the surface roughness are obtained by experiments.

Investigation into Normal Pressure during Electrorheological Fluid-Assisted Polishing

The normal pressure in polishing area is investigated in electrorheological (ER) fluid-assisted polishing process. Under the influence of the non-uniform electric field, the dielectric particles in the ER polishing fluid are polarized to form the rigid core attached to the tool electrode due to the ER effect. In this work, the rigid core generated by the gathered mass of ER polishing fluid on the tip of tool electrode with the applied electric field is analyzed. The material is removed by abrasive particles under the effect of normal pressure and velocity. Based on the theory of hydrodynamic lubrication, a mathematical model taking into account the normal pressure is derived. Further experiments about the normal pressure experiments changing with the applied voltage, spindle rotational speed and working gap are conducted and the experimental results are compared with the theoretical results, which confirm the validity of the presented model

Study on Combined Process of Micro-EDM and Electrorheological Fluid-Assisted Polishing

A novel machining method which is a combination of electrical discharge machining (EDM) and electrorheological fluid-assisted polishing (ERP) is presented to finish hard materials. The ER fluid is used as work fluid, which resulting in the material removal and polishing simultaneously. In this study, a series of machining experiments on aluminum alloy material are carried out to obtain the microstructures of machined surface using the different mode of material removal. Moreover, the ERP process can finish the micro-craters on workpiece surface after EDM to obtain better profile of removal region.

Investigation into Electrorheological Fluid-Assisted Polishing Optical Glass

Electrorheological (ER) fluid-assisted polishing process is the ultra precision finishing technologies for micro-aspherical lenses and dies. The principle of ER fluid-assisted polishing (ERP) is to use ER effect as a result of the application of electric field. The ER particles and abrasive particles suspended in silicone oil are polarized in which ER particles strongly attract each other and aggregate into chain like structure along the electric field lines, and the abrasive particles may adhere to the ER chain. The force acting on ER particles and abrasive particles in an electric field is calculated. Furthermore, experiments of polishing optical glass with Al2O3 are carried out to find the influential regularities of polishing time, rotational speed of micro-tool, voltage, the density of abrasives in ER fluid on the surface roughness.

Development of a circular-type integrated electrode tool for ER fluid-assisted polishing

This paper develops a newly-designed circular-type integrated electrode tool to make the abrasive particles in the electrorheological (ER) fluid concentrate around the tool end when the electric field is applied and it is suitable to polish not only the conductive material but also the non-conductive material in ER fluid-assisted polishing. The electric field of the integrated electrode tool is analysed. The polishing experiments for curved surfaces of tungsten carbide and optical glass with the developed integrated electrode tool are conducted to confirm the validity and suitability of the tool and to reveal the influence of the process parameters on the workpiece surface roughness.

An integrated tool for five-axis electrorheological fluid-assisted polishing

A five-axis electrorheological fluid-assisted polishing equipment is presented for the finishing of curved surfaces in this paper. An integrated electrode tool is specially designed to make the abrasive particles in the electrorheological fluid concentrate around the tool end when the electric field is applied and it is suitable to polish not only the conductive material such as tungsten carbide but also the non-conductive material such as optical glass. The polishing experiments for curved surfaces of tungsten carbide and optical glass are conducted to confirm the validity and suitability of the developed five-axis equipment with the designed integrated electrode tool and to reveal the influence of the process parameters on the workpiece surface roughness in electrorheological fluid-assisted polishing.

An investigation of effective area in electrorheological fluid-assisted polishing of tungsten carbide

Electrorheological (ER) fluid-assisted polishing is a novel polishing method for the finishing of micro-aspheric lens, dies and mirror. This paper investigates the effective area in the ER fluid-assisted polishing of tungsten carbide, which is used as the die material for the mass production of micro-aspheric glass lens. The effective area is defined as the area in which the abrasive particles concentrated in the vicinity of the tool tip makes the effective material removal from the workpiece. The electric field strength applied between the tool and the workpiece is analysed. The interacting forces between particles suspended in the electrorheological fluid are calculated. An approach is proposed to predict the effective area and the experiments are conducted to confirm the validity of the proposed method.

Development of a Resin-Coated Micro Polishing Tool by Plasma CVD Method -Electrorheological Fluid-Assisted Polishing of Tungsten Carbide Micro Aspherical Molding Dies-

The viscosity of an electrorheological fluid (ER fluid) increases with an increase in the intensity of an electric field. In the case of ER fluid-assisted micro polishing the workpiece needs to be a conductive material such as tungsten carbide and the gap between the workpiece and the polishing tool, which both act as electrodes, must be the same size as the abrasive grain. It is difficult to maintain a small gap when polishing the surface of the workpiece. In order to prevent direct contact between the workpiece and the polishing tool, a resin-coated polishing tool has been developed. In this paper, a micro polishing tool was made using a plasma chemical vapor deposition method. The geometry of the polishing tool was examined by a finite element method (FEM) to optimize the concentration of the abrasive grains. In polishing machining using the tool, the width of the polishing groove was 35 μm, and polishing machining in a micro area was achieved.

Investigation into electrorheological fluid-assisted polishing

Electrorheological fluid (ER fluid) is a functional fluid with the property that its viscosity can vary with the applied electric field strength. This paper investigates a polishing method using the electrorheological fluid, known as ER fluid-assisted polishing, for the finishing of micro dies of tungsten carbide alloy, which are used for the mass production of micro aspheric glass lens. The machining principle of the ER fluid-assisted polishing is introduced. By proper design of experiments based on a Taguchi orthogonal array and by multi-variable linear regression, empirical models are developed for evaluation of the effect of the process parameters on the material removal depth and surface roughness obtained in the ER fluid-assisted polishing. Further experiments are conducted to confirm the validity of the developed statistical model by comparing the model predictions with the experimental results and meanwhile the influences of the process parameters on the polishing performance are revealed.

Development of an electrorheological fluid-assisted polishing tool for micro-aspherical molding dies(M^4 processes and micro-manufacturing for science)

Development of an electrorheological fluid-assisted polishing tool for micro-aspherical molding dies(M^4 processes and micro-manufacturing for science)

Electrorheological fluid-assisted ultra-precision polishing for small three-dimensional parts

This paper deals with a new machining method (electrorheological fluid-assisted polishing) for small three-dimensional parts such as micro-aspherical lens, die and mirror. The behavior of electrorheological particles and abrasive particles in the vicinity of the tip of the tool was observed by CCD microscope, and the electric field strength, electrode shape, and type of abrasive particles were investigated. It was clear that the electrorheological effect facilitates collection of the abrasive particles at the tool tip, even while the tool is rotating. Then, electrorheological fluid-assisted micro-aspherical generator system was developed, which is capable of micro-grinding and micro-polishing on the same machine. The system demonstrated the excellent polishing performance of small area after grinding process.