• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.10a
• /
• pp.192-197
• /
• 1998

Abrasive flow machining is useful to abrasive polish a internal or external surface of the free shape dimensional parts, which are used in many fields such as machine tool parts, semi-conductor, and medical component industries. The machining process is that two hydraulic cylinders, which are located surface to surface, are enforce media to the passage between workpiece and tooling part alternately, and then the abrasives included in the media pass the passage and polish the surface of workpiece. The media which is made of polymer and abrasive plays complex have workpiece by its viscoelastic characteristics. In this study, the media for AMF was made by mixing viscoelastic polymer with alumina and silicon carbide abrasive respectively. As a result, alumina include media is also the experiments of deburring the inside burr of in order to analyse the deburring machinability of abrasive flow machining according to various machining parameters which were media flow rate extrusion pressure, passage gap, media viscosity, abrasive content, and abrasive grain size.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.6
• /
• pp.49-54
• /
• 2007

Electropolishing, the anodic dissolution process without contact with tools, is a surface treatment method to make a surface planarization using an electrochemical reaction with low current density. Nitinol is a metal alloy composed of Ni and Ti around 50% respectively which has shape memory effect. Nitinol can be put various applications which require purity and high pricision surface of products. The aim of this study is to investigate the characteristic of electropolishing effect for nitinol workpieces. In order to analyze the characteristics of electropolishing effect, surface roughness and micro-burr size were measured in terms of machining conditions such as current density, machining time and electrode gap. The tendencies about improvement of surface roughness and deburring effect by electropolishing for nitinol workpieces were determined.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.03a
• /
• pp.203-208
• /
• 1998

Materials of the Frame hole in fishing trackle reel is made up a number large and small holes. Thus, it is difficult to effective machining. Abrasive flow machining(AFM) is useful to polish a internal or external surface of the 3-dimensional shape parts, which are used in many fields such as aerospace, automative, semi-conductor, and medical component industries. The machining process is that two hydraulic cylinders, which are located face to face, enforce abrasive media to the passage between workpiece and tooling parts alternately, and then the abrasives include in the media pass the passage and polish the surface of workpiece. The media which is made of polymer and abrasives plays the role of the tool for deburring or polishing complex shap workpiece by its viscoelastic characteristics. In this study, the abrasive media for abrasive flow machining was made by mixing viscielastic polymer with alunina and silicon carbide abrasive. Also, we present AFM device design and preliminary results of an investigation in to some aspects of the AFM process performance in fishing trackle reel.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1294-1298
• /
• 2005

In this study, combined micro press and surface finishing process are proposed to fabricate the micro nozzle array on a stainless steel sheet metal. In micro hole punching process the burr occurs inevitably, but the burr must be minimized in order to improve the quality and accuracy of the product. For this reason, subsequent magnetic field-assisted finishing technique is applied to remove the burr which exists around the nozzles for ink-jet printer head and proved to be a feasible for deburring by experiment. The deburring characteristics of sheet metals were investigated changing with polishing time and magnetic abrasive size. After the deburring, the burr size has remarkably reduced and roundness of the hole also has improved.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.6
• /
• pp.74-80
• /
• 2022

The surface status of a workpiece determines its functionality, product quality, and manufacturing costs. Thus, several finishing technologies have been widely investigated and applied to improve surface characteristics. In this study, rotational electro-magnetic abrasive finishing (REMAF) was suggested as a non-contact finishing process to achieve high geometric precision. To verify the effects of the REMAF process on burr removal on the surface of Al6061, experiments were conducted using the Taguchi method. Based on the experimental results analyzed by the S/N ratio and ANOVA, the optimal conditions were defined as A₃B₂C₃D₃ that corresponded to 1,800 rpm of rotational speed, 1.5 kg of abrasive particle weight, 0.7 mm of abrasive diameter, and 15 min of working time. In addition, the particle weight was a key attribute for deburring, whereas the working time was less effective.

• Design & Manufacturing
• /
• v.11 no.3
• /
• pp.51-55
• /
• 2017

Micro fuel cells have high reliability and long usage time. Among them, PEMFC (polymer Electrolyte Membrane Fuel Cell) is suitable as a portable power source because it is easy to fix electrolyte and simple structure. The bipolar plate, a key component of the fuel cell, is produced by cutting. In the case of micro fuel cell separator, burr is very small and the flow channel size in the separator is very small. Therefore, it is difficult to remove burrs in the usual way such as a brushing or ultra-sonic method. Therefore, this study proposed electrolytic polishing process and analyzed the characteristics of each condition by introducing the concept of roughness reduction rate. In addition, the ultrasonic process was added to analyze the effect of ultrasonic addition.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.15 no.5
• /
• pp.51-58
• /
• 2006

The old technique of sandblasting which has been used for paint of scale removing, deburring and glass decorating has recently been developed into a powder blasting technique for brittle materials, capable of producing micro structures larger than $100{\mu}m$. Recently, this technique is applied to fabrication of the glass cap for OELD packaging. But, micro crack is generated on the blasted glass, which cause to decrease fracture strength. In this paper, we investigated the effect of blasting parameters on surface characteristics, surface shape and fracture strength of the powder blasted glass surface.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.10a
• /
• pp.302-307
• /
• 2002

In electropolishing, the ion from the surface of the metal is eliminated by means of an electrical potential and current. Electropolishing is being generally known as a replacement for mechanical finishing. In addition to making a surface smoother, it is a more visible means of brightening, deburring, cleaning, stress-relieving and improving the physical characteristics of most metals and alloys. Therefore, the aim of the present study is to investigate the characteristic of electropolishing STS304 and A12024 in terms of current density, polishing time and electrode gap, etc.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.11
• /
• pp.71-78
• /
• 2003

The exit burrs in the micro-drilling of precision miniature holes are of interest, especially for ductile materials. As burrs from this process can be difficult to remove, it is important to acquire the way of predicting burr types as well as optimal cutting conditions which minimize the burrs. In this paper, an artificial neural network was used for the prediction of burr formation in micro-drilling. First, the influence of cutting conditions including cutting speed, feed and drill diameter on the exit burr characteristics, such as burr size and type, were observed and analyzed. Then. the burr types were classified by using the influential experimental data as input parameters to the neural nets.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2006.05a
• /
• pp.1350-1356
• /
• 2006

The old technique of sandblasting which has been used for paint or scale removing, deburring and glass decorating has recently been developed into a powder blasting technique for brittle materials, capable of producing micro structures larger than $100{\mu}m$. In this paper, The surface characteristics of powder blasted glass surface were tested under different blasting parameter. Finally, we proposed a predictive model for powder blasting process using a neural network. A detailed analysis of the simulation results has been carried out and compared with experimental results.