Investigation into Electrorheological Fluid-Assisted Polishing Optical Glass

2011 ◽  
Vol 110-116 ◽  
pp. 1099-1106
Author(s):  
Yun Wei Zhao ◽  
De Xu Geng ◽  
Xiao Min Iu ◽  
Jin Tao Zhang
Keyword(s):  
Electric Field ◽  
Silicone Oil ◽  
Optical Glass ◽  
Electrorheological Fluid ◽  
Abrasive Particles ◽  
Micro Tool ◽  
Ultra Precision ◽  
Aspherical Lenses ◽  
Field Lines ◽  
Er Fluid

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.

Performance Evaluation of Electro-Rheological Fluid and Its Applications to Micro-Parts Fine-Machining

2006 ◽  
Vol 315-316 ◽  
pp. 352-356
Author(s):  
Qiu Sheng Yan ◽  
F.F. Bi ◽  
N.Q. Wu
Keyword(s):  
Performance Evaluation ◽  
Electric Field ◽  
Electrorheological Fluid ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Aspheric Surface ◽  
Surface Machining ◽  
Abrasive Particles ◽  
Micro Parts ◽  
Er Fluid

This article first presents the performance of Electrorheological Fluid (ER fluid). Thus, a new-style machining technique based on ER effect to form a tiny grinding wheel is developed for superfine machining. By adding abrasive particles to ER, an array of stable chains of ER particles can be shaped when an electric field is applied and abrasive particles are fixed to these chains structure. When the tip of tool is rotated, the abrasive particles rotate with the flow and a superfine grinding process come into being. This process is expected to be applicable to the aspheric surface machining of micro miniature components made of optic glass or other hard-brittle materials.

Study on Material Removal in Electrorheological Fluid-Assisted Polishing

2011 ◽  
Vol 314-316 ◽  
pp. 1131-1134
Author(s):  
Lei Zhang ◽  
Yun Wei Zhao ◽  
Zhuo Yang
Keyword(s):  
Electric Field ◽  
Material Removal ◽  
Electrorheological Fluid ◽  
Experimental Results ◽  
Abrasive Particles ◽  
Conductive Materials ◽  
Diamond Particles ◽  
Theoretical Predictions ◽  
Polishing Fluid ◽  
Er Fluid

The material removal is investigated in electrorheological (ER) fluid-assisted polishing of conductive materials. The combination structure of ER particles with abrasive particles in ER polishing fluid is discussed when the electric field is applied. The forces exerted on the abrasive particles for material removal are analyzed. According to Preston’s equation, a model for material removal of the polished conductive workpiece is derived. Polishing experiments with diamond particles for WC is conducted and the experimental results are compared with the theoretical predictions, which confirm the validity of the presented model.

YIELD PROCESS OF ELECTRORHEOLOGICAL FLUID WITH POLYANILINE PARTICLE

1994 ◽  
Vol 08 (25) ◽  
pp. 1563-1575 ◽  
Author(s):  
KIYOHITO KOYAMA ◽  
KEIJI MINAGAWA ◽  
TAMOTSU YOSHIDA ◽  
NORIYUKI KURAMOTO ◽  
KATSUFUMI TANAKA
Keyword(s):  
Shear Stress ◽  
Electric Field ◽  
Particle Concentration ◽  
Silicone Oil ◽  
Electrorheological Fluid ◽  
Yield Behavior ◽  
Wide Range ◽  
Dc Electric Field ◽  
Er Fluid ◽  
Flow Experiments

Electrorheological behaviors of polyaniline/silicone oil suspension were observed by using a modified Couette type rheometer with high resolution for shear stress. The yield behaviors were examined over a wide range of shear strain. The storage modulus and loss tangent were determined under a constant dc electric field. It was clarified that the polyaniline-based ER fluid yields two different strain amplitudes, i.e. about 1% and 50%. The stress-strain curves obtained from shear flow experiments also suggested the existence of two-step yield process. The yield process was found to be dependent on the electric field strength and the particle concentration in different manners. The yield behavior observed is discussed in relation to the structure of particle clusters which causes the ER effect.

Measurement of Interaction Forces at Small Distance under Electric Field in a Smectite Dispersed Silicone Oil Based ER Fluid

2001 ◽  
Vol 15 (06n07) ◽  
pp. 811-816 ◽  
Author(s):  
Toyohisa FUJITA ◽  
Toshio MIYAZAKI ◽  
Toshiharu TANAKA ◽  
Ke Jun Liu ◽  
Eiich KUZUNO ◽  
...  
Keyword(s):  
Electric Field ◽  
Silicone Oil ◽  
Small Distance ◽  
Surface Forces ◽  
Attraction Force ◽  
Interaction Forces ◽  
Repulsive Energy ◽  
Inflection Points ◽  
Dc Electric Field ◽  
Er Fluid

The apparatus to measure interaction forces under an electric field at small distance between a conductive hemisphere and a flat plate has been developed. The surface forces at small distance sandwiched ER fluid dispersing ultrafine smectite particles (20 to 50 nm thickness) in silicone oil has been measured. This fluid shows 0.7 kPa of apparent yield stress by applying 2.5 kV/mm of DC electric field. When an electric field applies to this ER fluid, the repulsive energy curves shows inflection points at about 0.2 μ m distance periodically at small distance of less than 1 μ m because the repulsion force decreases for a vacancy of particles after the particles are pushed out and the dipole attraction force acts between hemisphere and plate. On the other hand, when the electric field becomes off and it passes enough time, the inflection points is observed more shorter distance of about 0.15 μ m periodically. The coagulated particle size is estimated about 0.15 μ m under no electric field and becomes larger by applying electric field.

CONDUCTIVITY AND FORCE BETWEEN PARTICLES IN A MODEL ELECTRORHEOLOGICAL FLUID I: CONDUCTIVITY

1996 ◽  
Vol 10 (23n24) ◽  
pp. 3315-3325 ◽  
Author(s):  
C.W. WU ◽  
Y. CHEN ◽  
X. TANG ◽  
H. CONRAD
Keyword(s):  
Electric Field ◽  
Glass Bead ◽  
Silicone Oil ◽  
Field Enhancement ◽  
Water Film ◽  
Electrorheological Fluid ◽  
Large Strains ◽  
Electric Field Enhancement ◽  
A Chain ◽  
Water Contents

The conductivity of silicone oil with various water contents and that of a single-row chain of glass beads in silicone oil were determined as a function of electric field and spacing between the particles produced by tensile and shear strain. The conductivity of the silicone oil depended sensitively on its water content; that of the chain was three orders of magnitude greater than the silicone oil alone, but decreased rapidly with separation of the particles. The conductivity of the water film on the glass bead surface and the electric field enhancement in the oil gap between the beads were derived from the data. The measured current density along a chain of particles was in accord with that predicted by a conductivity model for electrorheological response. At large strains the separation of the beads in a chain became localized between one set of adjacent beads and they oscillated back-and-forth in the gap, leading ultimately to rupture of the chain with increased strain.

Position Control of a Cylinder Using a Hydraulic Bridge Circuit With ER Valves

1997 ◽  
Vol 122 (1) ◽  
pp. 202-209 ◽  
Author(s):  
Seung-Bok Choi ◽  
Woo-Yeon Choi
Keyword(s):  
Electric Field ◽  
Position Control ◽  
Bridge Circuit ◽  
Silicone Oil ◽  
Network Control ◽  
Operational Parameters ◽  
Pressure Drops ◽  
Feedback Error Learning ◽  
Feedback Error ◽  
Er Fluid

This paper presents the position control of a double-rod cylinder system using a hydraulic bridge circuit with four electro-rheological (ER) valves. After synthesizing a silicone oil-based ER fluid, a Bingham property of the ER fluid is first tested as a function of electric field in order to determine operational parameters for the ER valves. On the basis of the level of the field-dependent yield stress of the composed ER fluid, four cylindrical ER valves are designed and manufactured. Subsequently, step responses for pressure drops of the ER valve are empirically analyzed with respect to the intensity of the electric field. A cylinder system with a cart is then constructed using a hydraulic bridge circuit with four ER valves, and its governing equation of motion is derived. A neural network control scheme incorporating the proportional-integral-derivative (PID) controller is formulated through the feedback error learning method, and experimentally implemented for the position control of the cylinder system. Both regulating and tracking position control responses for square and sinusoidal trajectories are presented in time domain. In addition, a tracking durability of the control system is provided to demonstrate the practical feasibility of the proposed methodology. [S0022-0434(00)00701-2]

ELECTRORHEOLOGICAL BEHAVIOR OF CHITOSAN DERIVATIVE SUSPENSIONS

2001 ◽  
Vol 15 (06n07) ◽  
pp. 1025-1032 ◽  
Author(s):  
Ung-su Choi ◽  
Byeng-gil Ahn ◽  
Oh-kwan Kwon
Keyword(s):  
Electric Field ◽  
Volume Fraction ◽  
Silicone Oil ◽  
Flow Behavior ◽  
Chitosan Derivative ◽  
Shear Yield Stress ◽  
Bingham Flow ◽  
Shear Yield ◽  
The Difference ◽  
Er Fluid

The electrorheological (ER) behavior of chitosan and chitosan phosphate suspensions in silicone oil was investigated. Chitosan and chitosan phosphate suspensions showed a typical ER response (Bingham flow behavior) upon application of an electric field. However, chitosan phosphate suspension exhibited excellent shear yield stress compared with chitosan suspension. The difference in behavior results from the difference in the conductivity of the chitosan and chitosan phosphate particles due to their degree of the polarizability. The shear stress for chitosan and chitosan phosphate suspensions showed a linear dependence on the volume fraction of particles. The values of structure factor, A s obtained 1 and 3~4 for chitosan and chitosan phosphate suspensions and it may be due to the formation of single-row chains and multiple chains upon application of the electric field. Throughtout the experimental results, chitosan and chitosan phosphate suspensions were shown to be an ER fluid.

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

2012 ◽  
Vol 184-185 ◽  
pp. 977-980
Author(s):  
Yun Wei Zhao ◽  
Lei Zhang ◽  
Zhuo Yang
Keyword(s):  
Glass Ceramic ◽  
Normal Pressure ◽  
Electrorheological Fluid ◽  
Tool Electrode ◽  
Electrical Field ◽  
Electrode Tool ◽  
Abrasive Particles ◽  
Series Of Experiments ◽  
Polishing Fluid ◽  
Er Fluid

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.

ELECTRORHEOLOGY OF DISPERSIONS OF BaxSr(1-x)TiO3 IN SILICONE OIL UNDER AC OR DC ELECTRIC FIELD

2012 ◽  
Vol 26 (14) ◽  
pp. 1250081 ◽  
Author(s):  
GLAUBER M. S. LUZ ◽  
ANTONIO J. F. BOMBARD ◽  
SILVIO L. M. BRITO ◽  
DOUGLAS GOUVÊA ◽  
SHEILA L. VIEIRA
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Electric Field ◽  
Silicone Oil ◽  
Ferroelectric Materials ◽  
Dc Electric Field ◽  
Ac Fields ◽  
Er Fluid ◽  
Constant Shear Rate

Electrorheology (ER) of ferroelectric materials such as nanometric BaTiO 3 is still not fully understood. In this paper, nanoparticles of Ba x Sr (1-x) TiO 3 (where x = 0.8, 0.9 or 1.0) were synthesized using the method of Pechini, calcinated at 950°C, and after, lixiviated under pH 1 or pH 5. A controlled stress rheometer (MCR-301) was used to make the ER characterization of dispersions made of Ba x Ti 1-x O 3 in silicone oil (30% w/w), where (a) shear stress as a function of DC electric field (under constant shear rate) or (b) shear stress as a function of shear rate (under constant AC or DC electric field) were measured. We observed that electrophoresis occurred under electric field DC, creating a concentration gradient which induced phase separation in ER fluid. On the other hand, under AC fields above 1 kV/mm, the ER effect is stronger than for DC field, and almost without electrophoresis. Furthermore, there is an AC frequency, dependent on the disperse phase, where the ER effect has a maximum.

Effect of Electrorheological Fluid Assistance on Micro Ultrasonic Machining

2009 ◽  
Vol 69-70 ◽  
pp. 148-152 ◽  
Author(s):  
T. Tateishi ◽  
K. Shimada ◽  
Nobuhito Yoshihara ◽  
Ji Wang Yan ◽  
Tsunemoto Kuriyagawa
Keyword(s):  
Brittle Materials ◽  
Electrorheological Fluid ◽  
Ultrasonic Machining ◽  
Dielectrophoretic Force ◽  
Abrasive Grains ◽  
Micro Holes ◽  
Micro Tool ◽  
Brittle Fractures ◽  
Er Fluid

Ultrasonic machining (USM) is an effective machining method for hard brittle materials. In the USM process, the slurry is supplied to the gap between the ultrasonic vibrating tool and the workpiece. Materials are removed by the accumulation of small brittle fractures made by the impacts of abrasive grains. In a previous study, we proposed electrorheological fluid (ER fluid) assisted-USM, and the effect of ER fluid-assisted USM was confirmed practically by machining precise micro-holes and micro-grooves on hard brittle materials. In the present paper, in order to confirm the effect of ER fluid assistance for micro USM in more detail, the behavior of abrasive grains in the machining area is observed. The effect of dielectrophoretic force acts on the abrasive grains and the effect of using ER fluid assistance are investigated. As a result, the abrasive grains can closely approach the micro tool by the effect of dielectrophoretic force and be fixed around the micro tool by the effect of ER fluid assistance. Under these conditions, the workpiece is removed primarily by the accumulation of small brittle fractures, and the chipping can be reduced.

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