Sustainable ultra-precision machining of titanium alloy using intermittent cutting

W. S. Yip,S. To 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.2

In ultra-precision machining, it is well known that titanium alloys are difficult to cut materials. Machining processes of the materials commonly involves surface damages on machined components which subsequent machining steps or additional surface treatments are required for improving the machining quality, however, those processes acquire extra usages of raw materials and natural resources. Therefore, the environment problems related to ultra-precision machining of titanium alloys have been identified. This study applied a novel machining technology, intermittent diamond cutting in order to lower cutting temperature without using complicated equipment. In the experiments, few microgrooves were precut on the workpiece’s surface, which provided physical spaces for offering a cooling effect. Once the diamond tool passed the physical spaces, the accumulated cutting heat was released, consequently the induced surface damage and material swelling were minimized. The experimental results showed the enhancement of the machinability of titanium alloys, which reductions of cutting force, surface roughness, burr formation, error percentage of cutting profile accuracy and the level of material swelling on the machined surface are demonstrated. The proposed machining technology effectively improves the machinability of titanium alloys without requiring complicated equipment, facilitating the precision of titanium alloy components and sustainable ultra-precision machining simultaneously.

Principle Component Analysis and Social Network Analysis for Decision Support of Ultra-Precision Machining

Wai Sze Yip,Suet To 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.2

Ultra-precision machining (UPM) technology is actively engaged in manufacturing high technological products nowadays. However, as its complicated machining mechanisms, the induced intricate relationships between various machining factors erect barriers in obtaining optimal machining conditions. The goal of this study is to use social network analysis (SNA) and principal component analysis (PCA) to combine the metrics of individual UPM factors and prioritize UPM factors based on their combined characteristics. In the beginning, the preliminary results of SNA approach act as the input to conduct PCA and generate principal components (PCs). The PCs were then combined into multiple characteristic performance indexes (MPCI), which have the balance characteristics of all main metrics from SNA, allowing to demonstrate the UPM factors with relatively high MPCI to be the dominant variables in optimizations. Few case studies have been provided for validation of the effectiveness of adjustments in UPM factors with high MPCI on the machining outcomes. The optimal machining conditions with multi-objectives could be effectively reached by executing the machining strategies with considering the prioritized UPM factors from the results of the hybrid SNA and PCA approach in this study. Overall, this study contributes to providing a comprehensive reference to academics and industry for prioritizing UPM factors with considering the balanced machining outcomes and developing practical machining strategies.

UPCU의 초정밀위치결정에 따른 가공정밀도 향상에 관한 연구

김재열(J. Y. Kim),곽이구(L. K. Kwac),곽남수(N. S. Kwak),고명석(G. M. Seok) 한국생산제조학회 2006 한국생산제조시스템학회 학술발표대회 논문집 Vol.2006 No.5

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.

초정밀가공의 재질에 따른 발열과 가공정밀도에 관한 연구

이경일(Gyung-Il Lee),김재열(Jae-Yeol Kim) 한국기계가공학회 2018 한국기계가공학회지 Vol.17 No.1

At present, ultra-precision cutting technology has been studied in Korean research institutes, focusing on development of ultra-precision cutting tool technology and ultra-precision control engineering. However, the developed technologies are still far behind advanced countries. It focuses on metals including aluminum, copper and nickel, and nonmetals including plastics, silicone and germanium which require high precision while using a lathe. It is hard to implement high precision by grinding the aforementioned materials. To address the issue, the ultra-precision cutting technology has been developing by using ultra-precision machine tools very accurate and strong, and diamond tools highly abrasion-resistant. To address this issue, this study aims to conduct ultra-precision cutting by using ECTS (Error Compensation Tool Servo) to improve motion precision of elements and components, and compensate for motion errors in real time. An IR camera is used for analyzing cutting accuracy differences depending on the heat generated in diamond tools in cutting to examine the heat generated in cutting to study cutting accuracy depending on generated heat.

UPCU의 초정밀위치결정에 따른 가공정밀도 향상에 관한 연구

김재열(J. Y. Kim),곽이구(L. K. Kwac),곽남수(N. S. Kwak),고명석(G. M. Seok) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

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.

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.

UPCU의 초정밀위치결정에 따른 가공정밀도 향상에 관한 연구

김재열,곽이구,곽남수,고명석 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

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.

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.

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.

미세가공 시스템을 이용한 미세 그루브 가공실험

이선우,이동주,이응숙,제태진 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

The needs for precision machining of micro to milli parts have been increased as the industry require high quality products, especially for the micro-machining of IT products. The ultra-precision machining system is essential for the micro machining of fine structures, which insures machining accuracy, low systematic and random error and repeatability. In this study, we developed micro machining system, which is equipped with air bearing stage for ultra precision machining and also we present the results of V-grooving experiments, conducted by the developed system, to verify the performance of system. The results show that the machined V-grooving had good accuracy with repeatable stability.