• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.11
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• pp.23-28
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• 2020

In general, lithography techniques are applied when machining single-crystal silicon in nanoscale applications; however, these techniques involve low degrees of freedom for the vertical shapes. By applying mechanical techniques to machine silicon, nanopatterns having various types of vertical shapes can be manufactured. In this study, we determined the ductile-brittle machining transition point and analyzed the- variation of the specific cutting resistance within the ductile machining region in nanoscale applications. When brittle fracture occurred during the nanoscale cutting, the depth of cut and cutting force increased and decreased rapidly, respectively. The first point of rapid increase in the depth of cut was defined as the ductile-brittle machining point. Subsequently, the shape of the machining tool was observed using a scanning electron microscope to calibrate the machining area, considering the tip blunting. The specific cutting resistance decreased continuously and converged to a certain value during the nanoscale cutting. The decrease and convergence in the value can be attributed to the decrease in the ratio of the arc length to the area of the machining tool and silicon.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.3
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• pp.207-213
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• 2014

A study was carried out to fabricate the cutting tool geometry with micro/nanoscale on the single crystal diamond tool by using the FIB. The FIB technique is an ideal tool for TEM sample preparation that allows for the fabrication of electron-transparent foils. The FIB is appropriate techniques to sample and subsequently define the chemical composition and the structural state of mineral inclusion on the micro/nanoscale. The combination of FIB with a SEM allows for 3D information to be obtained from samples including 3D imaging. Cutting strategies were demonstrated to improve the performance of cutting tool geometry and to generate high aspect ratio micro cutting tool. A finely focused beam of 30keV Ga+ ions was used to mill cutting tool shapes for various micro patterns. Therefore FIB sputtering is used to shape a variety of cutting tools with dimensions in the $1-5{\mu}m$ range and cutting edge radii of curvature of under 50nm.

• Journal of the Korean Vacuum Society
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• v.15 no.1
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• pp.110-116
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• 2006

The mechanical property and cutting performance of the cutting tools coated with nanoscale nyktukatered nitride film have been investigated. $Ti_{0.54}Al_{0.46}N-CrN$ and $Ti_{0.84}Al_{0.16}N-NlN$ systems, which showed super-lattice in nanoscale multilayered coating, were deposited on WC-Co insert by UBM sputtering, The superlattice coatings with different bilayer periods were manufactured by controlling deposition parameters. The superlattice formation and hardness of the nanoscale multilayered nitride film and the cutting performance of the insert coated with the film were examined. The hardness and cutting performance were dependent on the bilayer periods of the coatings. The flank wear of the inserts with superlattice coatings were decreased over $20\%$, compared to those of commonly used cutting tools coated with TiAIN single phase.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.54-58
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• 2007

This paper describes an atomic force microscope (AFM)-based instrument for measuring the nanoscale cutting edge profiles of diamond cutting tools. The instrument consists of a combined AFM unit and an optical sensor to align the AFM tip with the top of the diamond cutting tool edge over a submicron range. In the optical sensor, a aser beam is emitted from a laser diode along the Y-axis and focused to a small beam spot with a diameter of approximately $10{\mu}m$ at the beam waist, which is then received by a photodiode. The top of the tool edge is first brought into the center of the beam waist by adjusting it in the X-Z-plane while monitoring the variation in the photodiode output. The cutting tool is then withdrawn and its top edge position at the beam center is recorded. The AFM tip can also be positioned at the beam center in a similar manner to align it with the top of the cutting edge. To reduce electronic noise interference on the photodiode output and thereby enhance the alignment accuracy, a technique is applied that can modulate the photodiode output to an AC signal by driving the laser diode with a sinusoidal current. Alignment experiments and edge profile measurements of a diamond cutting tool were carried out to verify the performance of the proposed system.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.3
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• pp.3-6
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• 2008

Electrolytic in-process dressing (ELID) grinding is a new technique for achieving a nanoscale surface finish on hard and brittle materials such as optical glass and ceramics. This process applies an electrochemical dressing on the metal-bonded diamond wheels to ensure constant protrusion of sharp cutting grits throughout the grinding cycle. In conventional ELID grinding, a constant source of pulsed DC power is supplied to the ELID cell, but a feedback mechanism is necessary to control the dressing power and obtain better performance. In this study, we propose a new closed-loop wheel dressing technique for grinding wheel truing that addresses the efficient correction of eccentric wheel rotation and the nonuniformity in the grinding wheel profile. The technique relies on an iterative control algorithm for the ELID power supply. An inductive sensor is used to measure the wheel profile based on the gap between the sensor head and wheel edge, and this is used as the feedback signal to control the pulse width of the power supply. We discuss the detailed mathematical design of the control algorithm and provide simulation results that were confirmed experimentally.