Micro-scale surface texturing을 기반으로 한 저마찰효과에 대한 기초연구

채영훈(Younghun Chae),김석삼(SeockSam Kim) 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.39 No.-

Surface texturing of tribological application is another attractive technology of friction reducing. Also, reduction of friction is therefore considered to be a necessary requirement for improved efficiency of machine. In this paper attempts to investigate the effect of density for micro-scale dimple pattern using photolithography on bearing steel flat mated with pin-on-disk. We demonstrated the lubrication mechanism for a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter for lubrication condition. It is found that friction coefficient is depended on the density of surface pattern. It was thus verified that micro-scale dimple could affect the friction reduction considerably under mixed and hydrodynamic lubrication conditions from based on friction map. Lubrication condition regime has an influence on the friction coefficient induced the density of micro dimple.

Micro Surface Groove Pattern의 실험적 마찰기구 해석

채영훈(Younghun Chae),김석삼(Seocksam Kim) 한국트라이볼로지학회 2007 한국트라이볼로지학회 학술대회 Vol.2007 No.6

Surface pattern of tribological applications has potential technology of engineered surface. The current study investigated the effect of size and angle of micro-scale crosshatched grooved pattern on tool steel(SKD 11) using pinon-disk. The samples fabricated by photolithography and electrochemical etching process. We demonstrated the lubrication mechanism for a Stribeck curve. It was found that the friction coefficient is changed by an angle of crosshatch on contact surface. We discuss that analysis of experiment data has some trend of friction property for crosshatch grooved surface pattern. Also optimum crosshatch angle depend on groove size.

혼합 및 유체윤활하에서 micro-scale Crosshatch grooved surface pattern의 사잇각도에 따른 마찰특성

채영훈(Younghun Chae),김석삼(Seocksam Kim) 한국트라이볼로지학회 2006 한국트라이볼로지학회 학술대회 Vol.2006 No.6

Some surface pattern of tribological applications is an attractive technology of engineered surface. Therefore, friction reduction is considered to be necessary for improved efficiency of machines. This study investigated the effect of friction property for angles of micro-scale crosshatch grooved surface pattern on bearing steel flat mated with pin-on-disk. We obtain sample which can be fabricated by photolithography process. We discuss friction property depend on an angle of cross-hatch grooved pattern. We can verify the lubrication mechanism as a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter under the lubrication condition. It was found that the friction coefficient was related to angle of crosshatch on surface, even when surface pattern was the same density.

Micro-scale surface texture 마찰기구에 대한 실험적 해석

채영훈(Younghun Chae),김석삼(Seocksam Kim) 한국트라이볼로지학회 2005 한국트라이볼로지학회 학술대회 Vol.2005 No.6

The current study investigated the effect of Micro-scale surface pattern to understand the potential benefits of friction reduction and durability in relative contact. It was verified that the friction property with respect to the surface feature and geometry factor under lubricated sliding contact. Additionally, it was recognized from Stribeck curve that the friction property has a connection with geometry factor. This can explain the relationship between the friction property and a dimensionless parameter for lubrication condition. It is suggested that the ratio of dip is an important parameter for surface texture design.

디젤엔진 라이너표면의 마이크로 crosshatch 그루우브 패턴의 사잇각도에 따른 마찰제어기술

채영훈(Younghun Chae),김석삼(Seocksam Kim) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Surface pattern of tribological applications is an attractive technology of engineered surface. Therefore, friction reduction is considered to be necessary for improved efficiency of machines. This study investigated the effect of friction property for angles of micro-scale crosshatch grooved surface pattern on bearing steel flat mated with pin-on-disk. We obtain sample which can be fabricated by photolithography process. We discuss friction property depend on an angle of cross-hatch grooved pattern. We can verify the lubrication mechanism as a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter under the lubrication condition. It was found that the friction coefficient was related to angle of crosshatch on surface, even when surface pattern was the same density.

윤활미끄럼마찰에서 Micro-scale crosshatch grooved surface pattern의 size effect와 angle effect간 실험적 분석

채영훈(Younghun Chae),김석삼(Seocksam Kim) 한국트라이볼로지학회 2006 한국트라이볼로지학회 학술대회 Vol.2006 No.11

Surface pattern of tribological applications has potential technology of engineered surface. The current study investigated the effect of size and angle of micro-scale crosshatched grooved pattern on tool steel(SKD Ⅱ) using pin-on-disk. The samples fabricated by photolithography and electrochemical etching process. We demonstrated the lubrication mechanism for a Stribeck curve. It was found that the friction coefficient is changed by an angle of crosshatch on contact surface. We discuss that analysis of experiment data has some trend of friction property for crosshatch grooved surface pattern. Also optimum crosshatch angle depend on groove size.

자동차용 고무의 플라즈마 처리에 따른 표면개질

이승훈(SeungHun Lee),김석삼(SeockSam Kim) 한국트라이볼로지학회 2008 한국트라이볼로지학회 학술대회 Vol.2008 No.6

We studied about surface modification of two kinds rubber using auto-mobile by plasma treatment. Rubbers are NBR, ACM. Using plasma are O₂ plasma by electric microwave and Ar plasma by RF power during 5~30 minutes. FT-IR was used for analyzing about molecular structure and contact angle measurement was used for analyzing about surface energy. As growing power, wet angle was decreased. Because molecular structure was changed.

크레인용 시브 강재의 마멸특성 평가

박용재(Yongjae Park),류중북(Jungbuk Ryu),김석삼(Seocksam Kim) 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.39 No.-

The sliding wear characteristics of the crane sheave were investigated using a pin-on-disk rig tester. The experiment was conducted using a high carbon steel wire that was upper material, also carbon steel castings and carbon steel for machine structural use that was disk material. There are various operating conditions in this work. At the room temperature, we carried out the wear test under a grease lubrication. The results of wear test showed that carbon steel for machine structural use have lower wear volume, also the wear curves are linearly increased with increasing of sliding velocity. The wear mechanism of a disk is the abrasive, adhesion, and fatigue wear under lubrication.

카본 증착 중 기판 바이어스 전압이 잔류응력에 미치는 영향

장영준(YoungJun Jang),나종주(JongJoo Rha),김석삼(SeockSam Kim) 한국트라이볼로지학회 2005 한국트라이볼로지학회 학술대회 Vol.2005 No.11

a-C films deposited by d.c. magnetron sputtering were used in a case study to determine the relationship between some deposition parameters, such as changing substrate bias and temperature. The test films, ranging in thickness from 130 to 230nm, were deposited on silicon wafers(100) with silicon strip. The residual stress was evaluated for using the surface curvature method by means of Stoney's equation. Here, we controlled the velocity of carbon atom crashing into substrate by two type substrate bias method. In case of continuing bias induced method, compressive residual stress(-2.79, -1.48Gpa) was increased with growing thickness and hardness. In the rectangular wave bias induced method, on the other hand, the value of compressive residual stress(-0.14, -O.085Gpa) was almost zero at any thickness and hardness level. It was considered to have relations with the movement of multi-layer G-peak, which was created by bias volt adjustment in film deposition process, to a lower shift, the increase of bonding strain in Sp2 net work and the generation of Sp3. Therefore, compressive residual stress could be controlled by rectangular wave bias induced method.

임베디드 서모커플 센서 제조 및 미끄럼 마찰 계면온도 측정에 관한 실험적 연구

장범택(Beomtaek Jang),임영헌(Youngheon Lim),김석삼(Seocksam Kim) 한국트라이볼로지학회 2013 한국윤활학회지(윤활학회지) Vol.29 No.6

This study investigated the interface temperatures for the sliding friction of three types of pins fabricated with thermocouple wires by the suction casting method. Optical microscopy was used to examine the surrounding material state at the bonding interface with the thermocouple wires. Friction tests were performed under dry sliding conditions against stainless steel 304 at nominal stresses of 1.42-4.25 MPa and sliding speeds of 0.5-1.25 m/s. Tribological data were collected using a custom-made pin-on-disk apparatus that measured he interface temperature and corresponding friction coefficient. Static tests were performed to demonstrate the functionality and reliability of the thermocouple wires-combined temperature sensor (TCTS). Each TCTS showed good linearity and sensitivity and very similar response times for the thermocouple and critical temperature during sliding friction.