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A novel magnetic field-assisted polishing technique was proposed for finishing 3D structured surface using a magnetic compound (MC) slurry. The MC slurry was prepared by blending carbonyl-iron-particles, abrasive grains and α-cellulose into a magnetic fluid which contains nano-scale magnetite particles. An experimental setup was constructed firstly by installing an oscillation worktable and a unit onto a polishing machine. Then, experimental investigations were conducted on oxygen-free copper workpiece with parallel distributed linear V-grooves to clarify the influence of the polishing time and abrasive impact angle on the grooves surface qualities. It was found that (1) the groove form accuracy, i.e. the form retention rate η varied with the polishing locations. Although the form retention rate η deteriorated during the polishing process, the final η was greater than 99.4%; (2) the effective impact angle θm affected the material removal and form accuracy seriously. An increase of the absolute value θm resulted with an increase of material removal rate and a decrease of the form accuracy; (3) the work-surface roughness decreased more than 6 times compared with the original surface after MC slurry polishing. These results confirmed the performance of the proposed new magnetic field-assisted polishing method in the finishing of 3D-structured surface.

The objective of this study is to achieve a high-precision and high-efficiency machining process for industrial components of the polyether ether ketone (PEEK) resin, such as the inspection socket of a connector or semiconductor packages. However, the drilling of holes in PEEK resin is challenging. Because PEEK resin is a thermoplastic resin, it can soften or melt owing to the heat generated during processing, which causes burrs and degrades the accuracy of the machined hole, thereby resulting in quality deterioration and hindering post-processing. Since the thermal conductivity of plastic materials including PEEK resin is lower than those of metals, the heat generated during processing does not dissipate to the outside of the workpiece, and the effect of the processing temperature on the processing accuracy is significant, particularly during drilling. Hence, a workpiece is cooled via a cold gas supply in this study. The effect of cold gas cooling on the machined hole accuracy and cutting state in the small-hole machining of PEEK resin is investigated. Results show that cooling the workpiece effectively decreases the cutting temperature and improves the machined hole accuracy. Under the experimental conditions, the combination of nonstep drilling and cooling enables high-precision drilling at approximately the same accuracy as step drilling. [ABSTRACT FROM AUTHOR]

This study investigates the development of an ultrasonic vibration-assisted magnetic compound fluid (MCF) polishing technology for final polishing. The fabrication of an experimental apparatus entails an ultrasonic polishing unit, and the experimental investigation of its performance in surface polishing is described. In addition, ultrasonic vibration-assisted MCF polishing under different applied methods of ultrasonic vibration is studied. The experimental results indicate that applying ultrasonic vibration to the workpiece improves the surface roughness and material removal rate when the ultrasonic vibrations are changed. In addition, across the range of polishing conditions employed in this study, the precision surface roughness and high material removal rate can be easily obtained on the acrylic plate by applying an elliptical vibration to the ultrasonic vibration. [ABSTRACT FROM AUTHOR]

The magnetic compound fluid (MCF) polishing process is a precision finishing method that has been applied to a large variety of materials, from soft optical polymers to hard ceramics. The purpose of this study is to extend the working life of MCF slurry. In this paper, we focus on the drying phenomenon of MCF slurry during polishing, and we develop a new water supply system that uses an ultrasonic atomization mechanism. This system can moisturize the MCF polishing area locally. Polishing experiments involving supplying water to MCF slurry are carried out, and extending the working life of MCF slurry is discussed. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced plastic (CFRP) is used for various mechanical structures because of its superior mechanical and physical properties. Industrial applications of CFRP require high quality, efficiently drilled holes. However, it is difficult for conventional methods, such as drilling, helical milling, and so on to meet industry requirements. Therefore, this study proposed a novel method for drilling holes in CFRP products. This new method is performed by replacing the revolving motion of the tool in conventional helical milling (CHM) with conical pendulum motion, in which the tool axis is tilted toward the hole axis at a certain angle, consequently called tilted helical milling (THM). As a step toward the establishment of the new method, in this work, the hole formation process, the cross-sectional area of work materials removed per tool revolution, and the zero cutting speed point problem in THM were theoretically compared with those in CHM. Then, experiments were performed to confirm the theoretical analysis in terms of the variations in the cross section profile of the drilled hole, the drilling forces, the hole quality at entrance/exit, and the chip removal. The obtained results revealed that during hole drilling by THM, a circumferential Vgroove exists between the end face of the tool and the bottom of the hole, whereas in CHM, this phenomenon does not occur. This fact is beneficial to timely chip removal, drilling force reduction, and zero cutting speed point problem avoidance. Subsequently, high quality holes can be successfully obtained with high efficiency by THM. [ABSTRACT FROM AUTHOR]