• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2007년도 추계학술대회 논문집
• /
• pp.128-129
• /
• 2007

Cr-Al-N, Cr-Si-N 그리고 Cr-Al-Si-N 코팅막을 WC-Co 모재위에 AIP법과 DC 마그네트론 스퍼터링 법을 결합한 하이브리드 시스템을 이용하여 합성하였으며, Si함량에 따른 Cr-Al-Si-N 코팅막의 미세구조, 기계적 특성과 마찰 거동에 관해 비교 연구하였다. Cr-Si-N(${\sim}35GPa$)과 Cr-Al-Si-N(${\sim}55GPa$) 코팅막의 경도값은 CrN(${\sim}23GPa$)과 Cr-Al-N(${\sim}25GPa$) 코팅막과 비교하여 각각 증가하였고, CrN(${\sim}0.50$)과 Cr-Al-N(${\sim}0.84$)의 평균 마찰계수는 Si 함량이 9 at.% 일때, Cr-Si-N(${\sim}0.30$)과 Cr-Al-Si-N(${\sim}0.57$)으로 각각 감소하였다.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2007년도 추계학술대회 논문집
• /
• pp.130-131
• /
• 2007

초고경도 박막을 얻기 위해 질화물을 이용한 CrN / CrAlN 초격자 박막을 CFUBM 시스템을 통해 합성하였다. 초격자 박막의 각층의 두께 (${\lambda}$)는 기판의 회전 속도를 이용하여 제어하여 4.4 에서 44.1 nm 까지 합성하였다. 박막의 결정구조 및 미세구조를 분석하기 위하여 고분해능 X선 회절 분석기 (HR-XRD)를 이용하였으며, 박막의 기계적 성질은 나노 인덴터와 ball on disk tester를 통해 분석하였다. CrN / CrAlN 초격자 박막은 각층의 두께 (${\lambda}$)에 따라 28.77 GPa에서 31.97 GPa의 경도 값을 나타내었으며, 미세구조와 기계적 특성이 변화를 관찰할 수 있었다.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
• /
• pp.310-317
• /
• 2000

Tribological properties of friction materials containing different volume ratios of solid lubricants (graphite and MoS$_2$) were studied using a pad-on-disk type friction tester. Morphology and thickness of the friction film were carefully examined to correlate the friction performance with the property of the friction film. Results showed that the friction materials containing 16vo1. % of graphite and 5 vol. % of MoS$_2$exhibited best friction stability among others. In particular, the thickness of the friction film decreased as the amount of MoS$_2$increased and severe friction oscillation was observed when the friction material contained MoS$_2$only (21 vol. %). Microscopic observations and friction tests suggested that the coherent thick transfer film improved the friction stability.

• 한국표면공학회지
• /
• 제32권3호
• /
• pp.472-483
• /
• 1999

Hard coatings playa continuously increasing role in the field of tribology as well as for decorative applications. In both areas they are often also exposed to corrosive media. While especially hard nitride coatings show a high corrosion resistance for themselves, hard $coating_strate systems may suffer from a severe corrosion attack due to the defects in the coating structure (pores, pinholes) resulting from the PVD-typical film morphology. While a huge number of investigations cover the tribological properties, only limited studies deal with the corrosion behavjour of coating substrate systems and attempts are made to improve their corrosion resistance. The present paper shortly describes the corrosion mechanisms and repots characteristic examples of the system behaviour. Special emphasis is laid on recent investigations to improve the corrosion resistance by alloying, interlayers or multilayered coating structures.es.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 C
• /
• pp.1737-1739
• /
• 2004

Diamond-like carbon (DLC) films were prepared with RF-PECVD (Plasma Enhanced Chemical Vapor Deposition) method on coming glass and silicon substrates using methane ($CH_4$) and hydrogen ($H_2$) gases. We examined the effects of $CH_4$ to $H_2$ ratios on tribological and optical properties of the DLC films. The structure and surface morphology of the films were examined using Raman spectroscopy and atomic force microscopy (AFM). The hardness of the DLC film was measured with nano-indentor. The optical properties of DLC thin film were investigated by UV/VIS spectrometer and ellipsometry. And also, solar cells were fabricated using DLC as antireflection coating before and after coating DLC on silicon substrate and compared the efficiency.

• Journal of Advanced Marine Engineering and Technology
• /
• 제32권2호
• /
• pp.262-267
• /
• 2008

Plasma immersion ion beam (PIIB) nitriding process is an environmentally benign and cost-effective process, and offers the potential of producing high dose of nitrogen ions in a way of simple, fast and economic technique for the high plasma flux treatment of large surface area with nitrogen ion source gas. In this report PIIB nitriding technique was used for nitriding on austenite stainless steel of AISI304 with plasma treatment at $250{\sim}500^{\circ}C$ for 4 hours, and with the working gas pressure of $2.67{\times}10^{-1}$ Pa in vacuum condition. This PIIB process might prove the advantage of the low energy high flux of ion bombardment and enhance the tribological or mechanical properties of austenite stainless steel by nitriding, Furthermore, PIIB showed a useful surface modification technique for the nitriding an irregularly shaped three dimensional workpiece of austenite stainless steel and for the improvement of surface properties of AISI 304, such as hardness and strength

• 한국재료학회지
• /
• 제10권1호
• /
• pp.83-89
• /
• 2000

$Si_3N_4$에 2wt% $Al_2O_3$와 6wt% $Y_2O_3$을 첨가한 분말을 가스압 소결 방법으로 시편을 제조하였다. 이때 소결시 시간변화에 따른 공기 중에서 마모 특성을 비교하였다. 소결 시간에 따른 마모 특성의 변화는 기계적 성질, 즉, 파괴인성 등이 영향을 주는 것으로 나타났다. 소결 시간이 길어지면 큰 elongated 입자의 과잉성장에 따라 곡강도 및 파괴인성이 낮아져 이 결과 마모가 증가되었다. 이때 나타난 결과에 의하면 공기 중에서 질화규소의 마모특성에 영향을 주는 인자는 여러 가지 기계적 특성 중에서 파괴인성 및 곡강도가 미치는 영향이 크게 나타났다.

• KSTLE International Journal
• /
• 제3권1호
• /
• pp.43-48
• /
• 2002

Dry sliding wear and friction test of CrN coaling on two types of aluminum alloy substrates,6061 Al and 7075 Al deposited by arc ion plating, was peformed with a ball-on-disk tribometer. The effects of normal Bead and the mechanical properties of substrate on the friction coefficient and wear-resistance of CrN coating were investigated. The worn surfaces were observed by SEM. The results show that surface micro-hardness of CrN- coated 7075 Al is higher than that of CrN-coated 6061 Al. With an increase in normal lead, wear volume increases, while the friction coefficient decreases. The friction coefficient of CrN-coated 6061 Al is higher than that of CrN-coated 7075 Al, while the wear-resistance of CrN-coated 6061 Al is lower than the CrN-coated 7075 Al's, which indicates that the substrate mechanical properties have strong inf1uences on the friction coefficient and wear of CrN coating. The main wear mechanism was fragments of CrN coating, which were caused by apparent plastic deformation of substrate during wear test.

• KSTLE International Journal
• /
• 제7권1호
• /
• pp.14-17
• /
• 2006

In this paper, we report on the replication of surface topography of natural leaf of Lotus onto thin polymeric films using a capillarity-directed soft lithographic technique. PDMS molds were used to replicate the surface. The replication was carried out on poly(methyl methacrylate) (PMMA) film coated on silicon wafer. The patterns so obtained were investigated for their friction properties at micro-scale using a ball-on-flat type micro-tribo tester, under reciprocating motion. Soda lime balls (1 mm diameter) were used as counterface sliders. Friction tests were conducted at a constant applied normal load of $3000{\mu}N$ and speed of 1mm/s. All experiments were conducted at ambient temperature ($24{\pm}1^{\circ}C$) and relative humidity ($45{\pm}5%$). Results showed that the patterned samples exhibited superior tribological properties when compared to the silicon wafer and non patterned sample (PMMA thin film). The reduced real area of contact projected by the surfaces was the main reason for their enhanced friction property.

• 한국산학기술학회논문지
• /
• 제8권4호
• /
• pp.697-702
• /
• 2007

마찰 마모에 대한 트라이볼로지 특성은 표면 재질에 대하여 중대한 영향을 끼친다. 더욱이 자동차의 가혹한 운전조건하에서의 엔진오일의 경우 내스커핑성과 시져는 트라이볼로지 특성에 상당히 중요하다. 본 연구에서는 펠렉스 마찰 마모시험기를 이용 첨가제들을 자동차 엔진오일에 널리 쓰이는 윤활기유에 첨가하여 트라이볼로지 특성을 연구하였다. 연구결과 다음과 같은 결론을 얻었다. 엔진오일에 표면거칠기의 특성을 가진 인산염(Phosphate)을 첨가하면 낮은 온도에서 우수하고, ZnDTP와 Ca-phenate를 첨가했을 때 높은 하중에서 내마모성, 극압성이 월등히 뛰어나며, ZnDTP와 P를 첨가했을 때는 높은 온도에서도 안정적으로 온도특성 또한 우수하였다.