단결정 다이아몬드공구 제작 기술을 통한 초정밀 미세패턴 가공 연구

정성택,송기형,최영재,백승엽,Jung, Sung-Taek,Song, Ki-Hyeong,Choi, Young-Jae,Baek, Seung-Yub 한국금형공학회 2020 한국금형공학회지 Vol.14 No.3

As the consumer market in the VR(virtual reality) and the head-up display industry grows, the demand for 5-axis machines and grooving machines using on a ultra-precision machining increasing. In this paper, ultra-precision diamond tools satisfying the cutting edge width of 500 nm were developed through the process research of a focused ion beam. The material used in the experiment was a single-crystal diamond tool (SCD), and the equipment for machining the SCD used a focused ion beam. In order to reduce the influence of the Gaussian beam emitted from the focused ion beam, the lift-off process technology used in the semiconductor process was used. 2.9 ㎛ of Pt was coated on the surface of the diamond tool. The sub-micron tool with a cutting edge of 492.19 nm was manufactured through focused ion beam machining technology. Toshiba ULG-100C(H3) equipment was used to process fine-pattern using the manufactured ultra-precision diamond tool. The ultra-precision machining experiment was conducted according to the machining direction, and fine burrs were generated in the pattern in the forward direction. However, no burr occurred during reverse machining. The width of the processed pattern was 480 nm and the price of the pitch was confirmed to be 1 ㎛ As a result of machining.

초정밀 FTS 시스템을 이용한 CNC Lathe 스핀들 이송오차 보상 및 가공정밀도 향상

김재열(JaeYeol Kim),곽남수(Namsu Kwak) 한국트라이볼로지학회 2011 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.27 No.1

The ultra-precision products which recently experienced high in demands had included the large areas of most updated technologies, for example, the semiconductor, the computer, the aerospace, the media information, the precision machining. For early 21st century, it was expected that the ultra-precision technologies would be distributed more throughout the market and required securing more nation-wise advancements. Furthermore, there seemed to be increasing in demand of the single crystal diamond tool which was capable of the ultra-precision machining for parts requiring a high degree of complicated details which were more than just simple wrapping and policing. Moreover, the highest degree of precision is currently at 50 ㎚ for some precision parts but not in all. The machining system and technology should be at very high performed level in order to accomplish this degree of the ultra-precision.

Dynamics Modelling and Simulating of Ultra-precision Fly-Cutting Machine Tool

Hanjing Lu,Yuanyuan Ding,Yu Chang,Gangli Chen,Xiaoting Rui 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.2

Dynamics modelling and simulating are the significant process to improve the machining accuracy of the machine tool. This paper is aimed to model and simulate the ultra-precision fly-cutting machine tool (UFMT) and find the relations between structure parameters and machined surface. In this paper, the multi-rigid-flexible-body dynamics model of the UFMT is firstly built by using transfer matrix method for multibody systems. After deducing overall transfer equation, overall transfer matrix, eigenfrequency equation and dynamics equations, the vibration characteristics and dynamics response of tool-tip are simulated and validated by tests. The machined surface is simulated by transferring displacement between the fly-cutting tool-tip and the workpiece into 3D curve. According to the simulation results, both the air-bearing stiffness of the flying-cutting head and cutting process parameters have effects on the machined surface.

Dynamic Analysis on Belt-Driven Spindle System of Machine Tools

Kim, Seong-Keol Korean Society for Precision Engineering 2002 International Journal of the Korean Society of Pre Vol.3 No.3

The need of ultra-precision machine tools, which manufacture and machine the high precision parts used in computers, semi-conductors and other precision machines, has been increased over years. Therefore it is important to design the driving parts, which affect significantly on their performances. In this paper, the dynamic analyses on the belt-driven system were explored. Relation of the acoustical natural frequency and the tension of belt was derived and presented through experiments. Also, while the dynamic loads on motor system were changed, dynamic deflections were calculated through finite element analysis. Nonlinear characteristics of the bearings having an effect on the dynamic performance were studied and the belt connecting the motor (driving part) to spindle of a machine tool (driven part) was modeled as truss and beam elements fur simulations under various conditions, and a beam element model was verified to be more useful.

Ultra-precision machining of a large amplitude umbrella surface based on slow tool servo

Peixing Ning,Ji Zhao,Shijun Ji,Jingjin Li,Handa Dai 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.11

Due to its excellent optical performance and system integration property, micro-nano structure function surface has been widely used in optical apparatus and energy collection equipment. But using traditional processing method can’t obtain a mirror-like surface with high form accuracy and low roughness for sake of its complex micro-nano structure. In this paper, a large amplitude umbrella surface is special designed and single point diamond turning (SPDT) technology based on slow tool servo (STS) is used for umbrella surface machining. The tool path generation, tool radius compensation and tool geometry optimization are detailed for fabricating the desired surface. A new method combined with constant angle and analytical mathematical optimization is proposed for tool path optimization. A large amplitude umbrella surface with the maximum amplitude 0.2 mm and period 8 per cycle is designed, and the machining experiment is carried out on Nanoform 250 ultra-precision machine tool. From the form accuracy 1 μm in surface residual error and 279.12 nm in RMS and the surface roughness 230.10 nm in Ra for the machined surface, it can be seen that a large amplitude umbrella surface is easily fabricated by SPDT under STS controlling.

초정밀 공구 위치설정 오차의 보정

박순섭(Soon-Sub Park),이기용(Ki-Young Lee),김형모(Hyoung-Mo Kim),이재설(Jae-Seol Lee) 한국기계가공학회 2007 한국기계가공학회지 Vol.6 No.4

Geometrical error of ultra-precision machining due to spherical tool alignment error is analyzed. Deviation of spherical edge, ranged several ten micrometers, generates vertical and horizontal error of tool path and affects profile accuracy of machined surface. Simulation of machined error shows effect of tool alignment error and enables to estimate alignment error. This work provides technical insights into the minimizing of geometrical error of ultra-precision machining.

초정밀 가공에서의 구형공구 위치설정 오차의 영향

박순섭(Soon-Sub Park),이기용(Ki-Young Lee),이호재(Ho-Jae Lee),황연(Yeon Hwang) 한국기계가공학회 2006 한국기계가공학회 춘추계학술대회 논문집 Vol.2006 No.-

Geometrical error of ultra precision machining due to spherical tool alignment error is analyzed. Deviation of spherical edge, ranged several ten micrometers, generates vertical and horizontal error of tool path and affects profile accuracy of machined surface. Simulation of machined error shows effect of tool alignment error and enables to estimate alignment error. This work provides technical insights into the minimizing of geometrical error of ultra precision machining.

Ductile Mode Machining of the Micro Pattern Made on YSZ Using Ultra-precision Shaping with a Diamond Tool

최환진,전은채,제태진,김정환,최대희,신보성,정우철,이윤희 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.12

Yttria stabilized zirconia (YSZ), which is a ceramic material, has a number of applications such as a refractory, thermal barrier coating and as a solid electrolyte for a solid oxide fuel cell (SOFC). Micro patterning the YSZ can increase the efficiency of the SOFC, but YSZ is difficult to mechanically machin. A few researchers have reported that an ultra-fine pattern can be mechanically machined on ceramic materials with no brittle fracture with a depth of cut close to sub-micrometers (called ductile mode machining). In the present study, the conditions for ductile mode machining of YSZ were studied. A 3-axis ultra-precision machine system and 90 diamond tool were employed to machine a micro pattern on YSZ. At first, when YSZ was machined with a depth of cut of 1 μm and 10 passes, the micro pattern was entirely fractured due to the brittleness of YSZ. Next, the micro pattern was machined with a depth of cut of 1 μm and 1 pass to verify how multi-pass machining affected the brittle fracture. A sparse brittle fracture occurred, which meant the depth of cut of 1 μm was too large for ductile mode machining. A mix of ductile mode machining and brittle mode machining was observed. Thirdly, when YSZ was machined with a depth of cut of 0.5 μm by 20 passes, the micro pattern was clearly machined with ductile mode machining. Thus, a transition point between ductile mode machining and brittle mode machining should exist at a depth of cut between 0.5 μm and 1 μm. A nanoscrach test was used to determine the transition point. The transition point was found to be 875 nm by analyzing the lateral force and the machined surface.

Development of an analysis system for geometric contour error evaluation in ultra-precision machining for microlens arrays

유효선,양정삼 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10

A basic principle for acquiring precisely shaped machined parts is to create dense tool path data. However, as the density of tool pathsincreases, the volume of data increases. The significant increase in data consumes more memory and machining time. Therefore, thecreation of tool path data of unlimited density is impractical. This paper proposes a contour error evaluation system. The system makescorrect decisions based on the expected quality of a workpiece. Specifically, the user creates tool path data by calculating deviations inthe contour in relation to variations in the intervals of the tool path. The user can create tool paths by adjusting the amount of tool pathdata within the desired quality level. Accordingly, before the start of the machining process, the user can predict any machining loss likelyto result from the excessive amount of data created in the creation phase. In addition, the tool path data of the proposed system areexperimentally compared with the actual shape of a part machined with a microlens array machining system.

초정밀 절삭가공에서 표면거칠기 특성 평가

강순준,이갑조,김종관 한국공작기계학회 2003 한국공작기계학회 추계학술대회논문집 Vol.2003 No.-

In this study, experiments were conducted with an ultra-precision machine, developed in domestic, to find the characteristics and the most suitable cutting conditions of ultra-precision machining. To maximize the performance of the machine, the machine was installed in a room that is protected from vibration and is maintained constant temperature and constant humidity. Selected work pieces are an aluminum-alloyed material, which has excellent corrosion resistance and has low deformation. The used tool is synthetic poly crystal diamond, which has excellent abrasion resistance and has low affinity. Four types of tool nose radius were used such as 0,0.1, 0.2 and 0.4㎜. Machining is performed with cutting speed of 500, 800 and 1000m/min., feed rate of 0.005, 0.008, 0.010㎜/rev. and cutting depth of 0.0005, 0.0025 and 0.005㎜ respectively which can generally be used in the field as a cutting condition. As a method of evaluation, surface roughness was measured for each cutting condition, and reciprocal characteristics are computed for each tool nose radius, cutting speed, feed rate and cutting depth. As a result, the most suitable cutting condition and characteristics of ultra-precision machining were identified which can usefully be applied in the industrial field.