Fluid Magnetic Abrasives Based on Micron-Sized Carbonyl-Iron Particles and Its Applications in the Precision Finishing Process

Author(s):  
Huanwu Sun ◽  
Shichun Yang

The fluid magnetic abrasive (FMA) is a new type of precision finishing abrasives, which is typically prepared by dispersing the magnetic particles, nonmagnetic abrasives, surfactants in a non-magnetizable carrier liquid. As the functional particles, the characteristics of magnetic particles have a great impact on the properties of FMA. In our experiment, the micron-sized carbonyl-iron (CI) particles (typical size: 3 μm–5 μm) are found to be ideally suited for the preparation of FMA. In this paper, the selections of micron-sized carbonyl-iron particles suitable for the FMA, the preparation techniques, the finishing mechanism and finishing process are presented. Some key parameters of FMA that may affect the finishing efficiency and the final surface roughness are analyzed theoretically. The experimental results are discussed as well in this paper.

2007 ◽  
Vol 334-335 ◽  
pp. 193-196
Author(s):  
Jae Lim You ◽  
B.J. Park ◽  
I.B. Jang ◽  
Hyoung Jin Choi

To enhance dispersion stability of magnetorheological (MR) fluids, hybrid magnetic particles of carbonyl iron (CI)/ poly(vinyl butyral) (PVB) with core/shell microstrcutre (CI-PVB) were prepared, since pure magnetic CI based MR fluid systems show severe sedimentation of the CI particles due to the large density mismatch with the carrier liquid and difficulties in redispersion after caking. The composite particles of CI-PVB have a lower density than that of the pure CI particles, while exhibiting almost original magnetic property of the CI. Both CI and CI-PVB particles were dispersed in mineral oil (20 vol%) and their MR characteristics were examined via a rotational rheometer with a magnetic field supplier. Various characterizations of the CI-PVB particles were performed via SEM, TEM and FT-IR. Both yield stress and flow curve of shear stress as a function of shear rate of the MR fluids were investigated under applied magnetic field strengths.


2010 ◽  
Vol 455 ◽  
pp. 161-164
Author(s):  
W.D. Li ◽  
Ming Lv ◽  
Sheng Qiang Yang

Fluid magnetic abrasivetool(FMA) is one kind of latest finishing abrasivetool which is a sort of suspended fluid composed by magnetic particles, nonmagnetic abrasive particles, surfactants in a non-magnetizable carrier liquid. After a period of working time, the performance-life of the abrasivetool ended because of the cutting- blade of the abrasives particles being passive. While the most costly component- the magnetic particles (carbonyl iron particles) can be reused. This paper has made up two recovery flows to separated carbonyl iron particles from others.


2006 ◽  
Vol 304-305 ◽  
pp. 579-583 ◽  
Author(s):  
Huan Wu Sun ◽  
Shu Cai Yang

The smart fluid abrasive (SFA) is a suspension of magnetically soft ferromagnetic particles and nonmagnetic abrasives in a carrier liquid. When the SFA is exposed to a magnetic field, a rapid and reversible fluid-to-solid phase transition occurs. Based on these distinctive features of SFA, a new type of precision finishing technology that can be used in the finishing of the revolved surface has been developed, and the finishing results have been proved in our experiments. In this paper, the SFA finishing mechanism and finishing process are presented, the influence of some basic parameters such as magnetic strength, size of abrasives, time of processing and relative motion between abrasives and working surface of work pieces are discussed as well.


2008 ◽  
Vol 144 ◽  
pp. 244-249 ◽  
Author(s):  
Yousef Razouk ◽  
Eric Duhayon ◽  
Bertrand Nogarede

This paper deals with the development of a new type of composites called "magnetoactivated" polymers and the exploration of some of their potential applications. "Magnetoactivated" polymers consist of small embedding (micron-sized) magnetic particles in a high elastic silicon matrix to render it magnetically active and at the same time mechanically strong. The experimental characterizations obtained (magnetic permeability and Young modulus) were systematically compared with the values resulting from the modeling of this material.The elastic properties of our "magnetoactivated" silicon motive us to use them as pump membranes, the evolution of the displacement of the pump membrane with the applied magnetic field were verified in ANSYS and experimentally for various contents of iron particles in the silicon matrix.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2503
Author(s):  
Tomas Plachy ◽  
Patrik Rohrer ◽  
Pavlina Holcapkova

This study demonstrates the formation of biocompatible magnetic particles into organized structures upon the application of an external magnetic field. The capability to create the structures was examined in silicone-oil suspensions and in a gelatine solution, which is commonly used as a blood plasma expander. Firstly, the carbonyl iron particles were successfully coated with gelatine, mixed with a liquid medium in order to form a magnetorheological suspension, and subsequently the possibility of controlling their rheological parameters via a magnetic field was observed using a rotational rheometer with an external magnetic cell. Scanning electron microscopy, infrared spectroscopy, and thermogravimetric analysis confirmed the successful coating process. The prepared magnetorheological suspensions exhibited a transition from pseudoplastic to Bingham behavior, which confirms their capability to create chain-like structures upon application of a magnetic field, which thus prevents the liquid medium from flowing. The observed dynamic yield stresses were calculated using Robertson–Stiff model, which fit the flow curves of the prepared magnetorheological suspensions well.


2020 ◽  
Vol 15 ◽  

For precision finishing of various newly and difficult of finish materials like optical glasses, metals, 3D-printed workpieces etc. Ball End Magnetorheological Finishing (BEMRF) finishing processes has been recently developed. This method utilizes a paste like fluid consisting of a base fluid which can be either water or oil, both magnetic and non-magnetic particles and stabilizing agents if necessary. Rheological behavior of this mixture of magnetorheological (MR) fluid with abrasives changes under the influence of magnetic field which in turn regulates the finishing forces during finishing processes. Present study critically reviews the BEMRF process used for achieving nano-level finishing variety of materials like mild steel, EN-31, copper etc. and the factors influenced this process so far which led to further advancements in this method.


2009 ◽  
Vol 416 ◽  
pp. 54-60
Author(s):  
Huan Wu Sun ◽  
Shi Chun Yang

The fluid magnetic abrasives (FMA) are a new type of precision finishing abrasives which are developed on the basis of the phase transition phenomenon caused by magnetic field. The rheological effect of FMA is the basis to achieve its finishing function, and has a great impact on the finishing capabilities and the final surface roughness. In order to get a better understanding of FMA finishing mechanism, the rheological effect models of FMA are deduced for the first time, the simulations and the experimental results are discussed as well in this paper.


2007 ◽  
Vol 24-25 ◽  
pp. 273-278 ◽  
Author(s):  
Huan Wu Sun ◽  
Shi Chun Yang

The fluid magnetic abrasives (FMA) are a new type of precision finishing abrasives, which can be used to finish the parts with intricate or complex shape to a quite low surface roughness value. As a key parameter, the magnetic saturation flux density has a great impact on the design of finishing devices and the control of finishing process. In order to measure the magnetic flux density and determine the magnetization curve of FMA, a new apparatus has been developed. The measuring mechanism and the experimental apparatus are presented. The experimental results are discussed as well in this paper.


2007 ◽  
Vol 339 ◽  
pp. 106-113 ◽  
Author(s):  
Yan Hua Zou ◽  
Takeo Shinmura

This paper describes a new efficient internal finishing process for a thick tubing (10~30mm in thickness), by the application of a magnetic field-assisted machining process using a magnet tool. Because a stronger magnetic force can be generated than conventional magnetic abrasives, it makes the internal finishing of thick non-ferromagnetic tubing possible. Moreover, in order to obtain a high-quality surface, this process method was developed using magnetic particles magnetically attracted on the magnet surface. This paper characterizes the processing principle and advantages of this process. Then, the mechanism of this finishing process was examined by a plane model experiment. It was clarified that the magnetism and shape of a magnetic particle influence realization possibility of this processing method, and it also influence the finishing characteristics.


2019 ◽  
Vol 31 (3) ◽  
pp. 339-348 ◽  
Author(s):  
Xincheng Song ◽  
Wenju Wang ◽  
Fufeng Yang ◽  
Guoping Wang ◽  
Xiaoting Rui

Magnetorheological elastomers are one kind of smart materials which consist of matrix materials and magnetic particles. The mechanical properties of magnetorheological elastomers were controllable under an external magnetic field. Applications of magnetorheological elastomers are limited as a result of their poor magnetorheological effect and mechanical performance, so enhancing the magnetorheological effect of them is critical for their application. Styrene-ethylene-butylene-styrene based thermoplastic elastomer was added to natural rubber to fabricate hybrid matrix–based magnetorheological elastomers. Zero modulus of magnetorheological elastomers increased from 0.50 to 0.64 MPa and magnetorheological effect increased from 28.00% to 43.75% with the addition of styrene-ethylene-butylene-styrene based thermoplastic elastomer. The contact angle of carbonyl iron particles with the matrix showed that styrene-ethylene-butylene-styrene based thermoplastic elastomer can improve the compatibility of carbonyl iron particles with the matrix. Fourier-transform infrared spectroscopy analysis has been carried out to investigate the internal structure of hybrid matrix–based magnetorheological elastomers.


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