scholarly journals Investigation on Polishing of Zirconia Ceramics Using Magnetic Compound Fluid: Relationship Between Material Removal and Surface Roughness

2021 ◽  
Vol 15 (1) ◽  
pp. 17-23
Author(s):  
Ming Feng ◽  
Youliang Wang ◽  
Yongbo Wu ◽  
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...  

Zirconia ceramics have excellent applicability in the aerospace, defense, new energy, automotive, electronics, and biomedical fields. However, few investigations have been conducted on the high-precision polishing of zirconia ceramics. In this work, a polishing method using a magnetic compound fluid slurry is proposed. First, the principle and the constructed experimental setup were presented. Then, the experiments were performed that characterized the surface profile after polishing, the effect of the working gap, and the effect of the concentration of carbonyl iron particles (CIPs) on the material removal and surface quality. The results showed that the material removal ability correlated positively with the surface roughness; the smallest working gap (0.5 mm) induced greater material removal ability and better surface roughness; higher CIP concentration enabled a higher polishing force to obtain higher material removal and better surface quality. The polishing results show that surface roughness Rz of 55 nm was obtained at the surfaces of zirconia ceramics, confirming that the proposed method has the potential for polishing of zirconia ceramics.

Author(s):  
Vasishta Ganguly ◽  
Tony Schmitz ◽  
Arthur Graziano ◽  
Hitomi Yamaguchi

Magnetic field–assisted finishing (MAF) is used to polish free-form surfaces. The material removal mechanism can be described as a flexible “magnetic brush” that consists of ferromagnetic particles and abrasives that arrange themselves in the working gap between the magnet and the workpiece. Relative motion between the brush and the workpiece causes microcutting and improves surface finish. In this study, the contributions of the magnetic and polishing force components to the total force were evaluated. The effect of varying the polishing conditions, such as the working gap and the size of the ferromagnetic iron particles, on polishing forces, surface roughness, and material removal rate was also analyzed. It was observed that the polishing forces varied considerably with working gap. Also, the iron particle size was found to have a strong relation to the rate at which the surface roughness improved. Surface roughness values of 2–3 nm were achieved.


2018 ◽  
Vol 12 (6) ◽  
pp. 921-929 ◽  
Author(s):  
Masato Okada ◽  
Makoto Shinke ◽  
Masaaki Otsu ◽  
Takuya Miura ◽  
Kuniaki Dohda ◽  
...  

Burnishing characteristics of a newly developed roller burnishing method were developed. The developed method can effectively control the sliding direction between the roller and a cylindrical workpiece by inclining the roller axis with respect to the workpiece axis. The outer surface of a round aluminum alloy bar was targeted. The influence of burnishing conditions on burnished-surface quality was investigated, and surface quality was evaluated based primarily on the surface roughness, surface profile, and external appearance. As observed, the burnished-surface quality was strongly influenced by the pressing force, roller-inclination angle, and number of tool passes. A superior surface quality could be realized by increasing the number of tool passes.


2012 ◽  
Vol 523-524 ◽  
pp. 161-166 ◽  
Author(s):  
Hui Ru Guo ◽  
Yong Bo Wu ◽  
Ya Guo Li ◽  
Jian Guo Cao ◽  
M. Fujimoto ◽  
...  

A kind of zirconia-coated carbonyl-iron-particles (CIPs), which show long-time stability against aqueous, is installed in magnetic compound fluid (MCF) to polish PMMA. Performance (normal polishing force and surface roughness) of zirconia-coated CIP based MCF slurry with different CIP concentrations is investigated. For comparison, the performances of the conventional non-coated CIP (i.e., HQ) based MCF slurry and MRF slurry in which DI-water is employed instead of MF are also examined. In the presence of Al2O3 abrasive particles, the use of zirconia-coated CIP based MCF slurry can not result in better polishing performances compared with conventional HQ CIP based MCF slurry; In the absence of Al2O3 abrasive particles, higher normal polishing force and smoother work-surface were obtained with the zirconia-coated CIP based MCF slurry rather than the MRF slurry; For the zirconia-coated CIP based MCF slurry without abrasive particles, the concentration of zirconia-coated CIP should be less than a certain value (in the current work, 70 wt. %), otherwise MCF slurry shows bad particle dispersion and is easily dried, resulting in the loss of its polishing ability.


2014 ◽  
Vol 1027 ◽  
pp. 52-57 ◽  
Author(s):  
Zeng Wen Liu ◽  
R.Y. Liu

s: Abrasive jet micromachining is considered as a promising precision processing technology for brittle materials such as silicate glass and silicon nitride that are increasingly used in various applications. In this study, some polishing experiments are conducted for hard-brittle materials by a micro slurry jet. The results show that the morphology and the integrity of the material surface are improved greatly after polishing. The average roughness (Ra) value of the silicate glass decrease from 2.32μm to 0.35μm and the average roughness (Ra) value of the Si3N4 decrease from 2.63μm to 0.34μm. The material removal mechanism and the surface formation mechanism are studied. The factors to influence the surface morphology, the surface quality and the surface roughness are analyzed in order to take measures to improve the surface quality and reduce the surface roughness value.


Author(s):  
Chunhui Chung ◽  
Glenn Melendez ◽  
Imin Kao

Wafers made of materials such as silicon, III-V and II-VI compounds, and optoelectronic materials, require high-degree of surface quality in order to increase the yield in micro-electronics fabrication to produce IC chips and devices. Measures of properties of surface quality of wafers include: nanotopography, surface morphology, global planarization, total thickness variation (TTV) and warp. Due to the reduction of feature size in micro-electronics fabrication, the requirements of such properties become more and more stringent. To meet such requirements, the wafer manufacturing processes of brittle semiconductor materials, such as slicing, lapping, grinding, and polishing have been continually improved. In this paper, the lapping process of wafer surface treatment is studied with experimental results of surface roughness and material removal rate. In order to improve the performance of lapping process, effects of mixed abrasive grits in the slurry of the free abrasive machining (FAM) processes are studied using a single-sided wafer-lapping machine. Under the same slurry density, experiments employing different mixing ratios of large and small abrasive grits, and various normal loadings on the wafer surface applied through a jig are conducted for parameter study. With various mixing ratios and loadings, observations and measurements such as the total amount of material removed, material removal rate, surface roughness, and relative angular velocity are presented and discussed in this paper. The experiments show that the half-half mixing ratio of abrasives removes more material than other mixing ratios under the same conditions, but with a higher surface roughness. The results of this study can provide a good reference to the FAM processes that practitioners use today by exploiting different mixing ratios and loadings of abrasive slurry in the manufacturing processes.


2021 ◽  
Vol 13 (5) ◽  
pp. 874-882
Author(s):  
Lijun Wang ◽  
Yongbo Wu

In this work, a new polishing method for zirconia ceramics was firstly proposed, which combined dielec-trophoresis effect with magnetic compound fluid polishing. A key experimental device was designed and constructed, and the influence behavior of dielectrophoresis phenomenon on the polishing efficiency, surface roughness and glossiness of zirconia ceramic workpiece were investigated. Also, the effects of voltage, electrode shape and electric field parameters on the polishing results were deeply discussed. The results showed that when the magnetic field was stronger, the polishing efficiency would become higher, while the surface quality of the workpiece getting worse. And the glossiness was positively correlated with the surface roughness. Moreover, the smaller the electrode shape and the larger the electric field gradient caused the better dielectrophoresis-assisted effect. It was indicated that when the electrode shape was a circle with a diameter of 20 mm and the voltage was 1500 V, the material removal efficiency was improved by 36.4% while ensuring the surface quality of zirconia ceramics.


2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Yuan Liu ◽  
La Han ◽  
Haiying Liu ◽  
Yikai Shi ◽  
Junjie Zhang

Machined surface quality has a strong impact on the functionality of silicon carbide-based components and devices. In the present work, we first analytically investigate the complex coupling of motions in annular polishing based on the Preston equation, which derives the influential parameters for material removal. Subsequently, we conduct systematic annular polishing experiments of reaction-bonded silicon carbide to investigate the influence of derived parameters on polished surface quality, which yield optimized polishing parameters for achieving ultralow surface roughness of reaction-bonded silicon carbide.


2006 ◽  
Vol 129 (2) ◽  
pp. 265-273 ◽  
Author(s):  
M. P. S. Krishna Kiran ◽  
Suhas S. Joshi

Surface roughness is one of the important quality characteristic of a micromachined component. This paper presents a model to predict surface roughness of micro-EDmachined surfaces. The model is based on the configuration of a single-spark cavity formed as a function of process parameters. Assuming the normal distribution of surface heights, the μ and σ(Rq) of the surface profile are evaluated after every spark. The model was further extended to capture the role of debris in micro-EDM in changing electric potential at the micropeaks on the cathode surfaces. The chemical kinetics approach was used to evaluate the change in plasma enthalpy and composition as a result of debris inclusion in the dielectric. The corresponding energy distribution between the electrodes was used to predict configuration of the single-spark cavity and the consequent surface roughness using the earlier surface roughness model. The modeling results were found to agree well with the micro-EDM validation experiments performed without and with the inclusion of artificial debris (iron particles) in the dielectric.


2010 ◽  
Vol 135 ◽  
pp. 303-308
Author(s):  
Feng Jiao ◽  
Bo Zhao ◽  
Xiang Liu

The surface roughness of machined surface is one of the important indicators to evaluate the workpiece machining quality. In order to clarify the change law of surface roughness in ultrasonic aided high-speed lapping with solid diamond abrasive, a series of ultrasonic and conventional lapping experiments of different engineering ceramics, such as Al2O3, ZrO2 and ZTA, were carried out on precision lathe with self-made high-speed ultrasonic lapping device. The research results show that the value of surface roughness in ultrasonic aided lapping is lower than that in conventional lapping. With the assistance of ultrasonic vibration, the surface quality can be improved obviously. In ultrasonic aided lapping, there is an optimum lapping pressure from which a better surface roughness value can be obtained. Because of different physical and mechanical properties, material removal mechanisms of the three kinds of engineering ceramics present different characteristics, which lead to the different surface roughness even though under the same lapping conditions. The research of the paper is helpful to optimize lapping technique and improve the surface quality.


2010 ◽  
Vol 139-141 ◽  
pp. 2146-2149
Author(s):  
Ying Ping Qian ◽  
Ju Hua Huang ◽  
Xi Zhi Zhou ◽  
Masanori Kunieda

In this paper, the attempt was made to study dry WEDG (Wire Electrical Discharge Grinding), the differences between dry WEDG and wet WEDG, especially the rods appearance and material removal speed and surface roughness were studied experimentally, the results are as follow: (1) The shape especially the symmetry of the rods fabricated with WEDG using kerosene as dielectric fluid is better than that of dry WEDG only using pure air as dielectric. (2) The material removal speed is obviously higher in wet WEDG than that in dry WEDG. (3) The surface roughness of the rods fabricated with wet WEDG is lower than that with dry WEDG;.(4) The wet WEDG can be used in the roughness machining to improve the speed, and the dry WEDG can be used in the finishing machining to advance the surface quality.


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