• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.130-130
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• 2000

타이타늄(CP Ti)과 타？늄합금은 인체의 골격을 구성하고 있는 물질과 가장 흡사한 물리적 성질과 우수한 생체적합성으로 인해 임플란트용 재료로 많이 사용되고 있으며, 최근에 인공관절이나 치근으로의 사용이 증가하고 있다. 그러나 교합면에서의 취약한 마모특성으로 인해 wear debris에 의한 골 흡수 및 이완 등을 야기하는 문제점으로, 이의 개선에 관한 연구가 활발히 진행되어 왔다. 다이아몬드상 카본 (Diamond-Like-Carbon) 박막은, 다이아몬드와 유사한 높은 경도, 내마모성 그리고 화학적 안정성 등의 매우 우수한 물리화학적 특성을 가지고 있는 박막재료로 고체 윤활박막으로서 hard disk나 VCR head drum의 보호막, 우주항공기의 bearing 재료코팅 등으로의 적용이 최근에 급격히 증가하고 있다. 본 연구에서는 이와 같은 특성을 지닌 다이아몬드상 카본 박막의 생체재료로의 적용을 위해, CP Ti과 Ti-6Al-4V에 13.56MHz를 사용하는 r.f PACVD법으로 DLC를 증착하여 생체적합적 특성을 조사하였다. C6H6 가스를 사용하여 1$\mu\textrm{m}$의 두께로 DLC 박막을 증착하였으며, 기판과의 밀찰력 향상을 위해 Si을 증간층으로 합성하였다. 마모특성은 pin-on-disk type wear tester을 사용하였으며 직경 5mm의 ruby ball로 실험을 수행하였다.

• Journal of the Korean institute of surface engineering
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• v.33 no.1
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• pp.38-47
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• 2000

A Ti(CN) layer was formed on aluminum alloy by using diethylamino titanium, hydrogen and nitrogen with the pulsed DC PACVD process. Effect of process parameters such as precursor evaporation temperature, duty ratio, frequency, voltage, $H_2$/$N_2$gas ratio on the properties of Ti(CN) layer were investigated. The layer thus obtained had high hardness and low friction coefficient. Detailed results on the hardness, surface morphology, XRD, WDS analysis, wear test and scratch test of this layer are presented.

• Journal of the Korean institute of surface engineering
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• v.35 no.4
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• pp.232-240
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• 2002

The composition and the microstructure of the Zn-Cr alloys electroplated in chloride bath with EDTA were studied according to electrolysis conditions. The cathode current efficiency decreased with increasing both Cr/(Cr+Zn) ratio and current density. The Cr content of the alloy deposits increased with Cr/(Cr+Zn) ratio and current density The phase structure of Zn-Cr alloy deposits changed from η-Zn through η-Zn+${\gamma}$'-ZnCr to ${\gamma}$'-ZnCr with increasing Cr content of alloys. The surface morphology of Zn-Cr alloy deposits changed from fine needle shaped crystallites through the mixed structure of needle-shaped and granular one to the colony structure with fine granular crystallites according to the change of phase structure

• Journal of the Korean institute of surface engineering
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• v.25 no.1
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• pp.16-23
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• 1992

Generally brittle eta phase produced during TiC deposition has a bad effect on the TRS (transverse rupture strength ; thoughness). Therefore it is necessary to reduce eta(η) phase for the improvement of tool life. At this experiment some properties (TRS, bonding strength, tool life, eta phase) have been investigated by inserting TiN or TiCN underlayer between TiC layer and substrate. The results obtained were as fellows; 1. by inserting underlayer eta phase was decreased and TRS was increased, but the bonding strength was decreased. 2. the diffusion of W, Co from the substrate was hindered by the underlayer. 3. TiC layer with TiCN underlayer had the finsest gain size. 4. by inserting underlayer (TiCN or TiN) the tool life was improved and especially notch and crater wear resistance was greatly improved.

• Journal of the Korean institute of surface engineering
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• v.32 no.4
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• pp.521-530
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• 1999

The corrosion resistance and the hardness of the tin-nickel alloy deposits electroplated in pyrophosphate bath were invesitigated according to electrolysis conditions and microstructure of the alloy. The weight loss of alloy deposits increased with the Sn content of single phase (Ni-Sn) alloy showing the lowest weight loss in the alloy with 54∼57wt% Sn. On the other hand, the multiphase alloy with 35∼42wt% Sn showed the highest one. The CASS test result was consistent with that of immersion test, and was good agreement with the corrosion data of polarization measurements. The hardness of alloy deposits decreased with the increase of Sn ratio in bath due to the grain size increase of the alloy. However, it increased noticeably with decreasing current density in the bath condition of low Sn ratio (0.1)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.136-137
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• 2014

주석계 전기도금액에 포함된 불소계 계면활성제는 분산 유화 소포 효과를 발휘할 수 있으며, 도금 금속 결정을 미세하게 하여 범프의 그레인 크기와 모양 특성을 개선하며, 범프의 높이 차 (WID, WIW) 감소 및 범프 내 빈 공간과 금속간 층의 균열 생성 방지에 영향을 주었음을 알 수 있었다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.215-222
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• 2007

Coating of Hot-dip galvannealed steel consists of various Fe-Zn intermetallic compounds. Since the coating is hard and there for is very brittle, the surface of steel sheet is easy to be ruptured during second manufacturing processing. This is called as powdering. In addition, forming equipment might be polluted with debris by powdering. Therefore, various research have been carried out to prohibit powdering fur improving the quality of GA steel. This paper carried out finite element analysis combined with damage model which simulate the failure of local layer of hot-dip galvannealed steel surface during v-bending test. Since the mechanical property of intermetallic compound was unknown exactly, we used the properties calculated from measurements. The specimen was divided into substrate, coating layer and interface layer. Local failure at coating layer or interface layer was simulated when elemental strain reached a prescribed strain.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2002.04b
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• pp.8-8
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• 2002

서멧이란(Cermet) '세라믹 경질상과 금속 결합상의 복합체"를 의미하나 절삭 골구계에서는 좁은 의미의 "TiC 혹은 Ti(CN)을 바탕을 Ni,Co를 결합상으로 하는 초경재료"를 의미한다. 이런한 서멧은 전략 물질적 성격이 강한 Co,W로 구성된 WC-Co 초경 합금을 대체하기 위해 고안되었는ㄴ데 ㄴ놓은 경도와 고온에서의 화학적 안정성, 낮은 비중과 저렴한 원료 가격등이 장점이나 WC-Co에 비해 상대적으로 낮은 인성이 문제점으로 지적 되어왔다.TiC-Ni 서멧의 낮은 인성을 향상시키기 위해 Ti(CN) 고용체를 바탕으로 하고 제2ㅇ, 제3의 탄화물이나 질화물을 첨가하는 개발 연구가 과거 30여 년간 진행되어왔다. 그러나 많은 연구결과가 조성 개발 위주로 진행되어 왔고, 또 실험간의 불일치와 재현성 결여로 인해 보여진 여러 현상에 대한 보편적인 결론을 내리기 힘든 점이 있었다. 특히, 미세구조와 기ㅔ적 특성에 관한 통합적이고 조직적인 연구가 진행되지 못하였다. 이번 발표에서는 발표자 실험실에서 지난 8 년 간 행하여 온 실험 결과를 바탕으로 탄화물서멧에 나타나는 독특한 현상, 고용체 탄질화물의 열역학적 안정성, 서멧 재료의 유심구조, 표면 에너지 및 strain, 에너지가 미세 구조 형성에 미치는 영향, 그리고 표면층 형성 등 서멧 개발에 관한 중요 관심사에 대해 간단히 살펴보려고 한다.해 간단히 살펴보려고 한다.

• Journal of the Korean institute of surface engineering
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• v.35 no.1
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• pp.5-10
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• 2002

This study was performed to investigate the influence of spraying condition to the coating layer properties of Fe-Cr-Ni-Mo-Si-B alloy using the HVOF. The investigations, such as thickness measurement, surface roughness, hardness, friction coefficient, resistance of corrosion were carried out. Matrix is prepared by gritting and coating layer is made of Fe-Cr-Ni-Mo-Si-B alloy powder using HVOF. Alumina gritting layers are superior to steel gritting layers. The less spaying distance, the more coating layer properties confirmed. The optimum spraying condition, in this study, was proved as 13inch spraying distance with feed rate 350rpm (78g/min).

• Journal of the Korean institute of surface engineering
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• v.30 no.6
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• pp.365-373
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• 1997

316L and 420 Stainless steels were deposited onto AZ9ID commercial magnesium alloy by plasma spray process with various gas flow rate of, TEX>$H_2$ secondary gas. And hardness as well as were track volume, coefficient of friction also had been measured. wear and hardness were measured by using reciprocal configuration tribometer and microghardness tester, respectively. Also, the microstructure of the coatings surface the cross sectional area of coating surface and cross sectional area of coaing/Substrate interface had been analyzed with Scanning Electron Microscope(SEM) and Optical microscope(OM). Finally, optimal process parameters for the improvement of coating efficiency such as mechanical property and wear behavior were examined.