• Tribology and Lubricants
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• 제8권2호
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• pp.20-25
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• 1992

Friction and wear behavior of hot isostatic pressed $Al_2O_3-TiC$ was experimentally examined. Pin-on-disk type friction and wear apparatus was designed and manufactured for the experiment. The experiments were conducted under unlubricated sliding motion in both low and high humidity for three kinds of sliding speed. $Al_2O_3-TiC$ and bearing steel were used as counterface materials. Friction coefficient, wear rate, and surface roughness were measured. Wear surface and wear debris were observed through optical microscope and SEM and analyzed by EDAX. The results showed that the counterface materials, the sliding speed, and the moisture at the sliding surface have significant influence on the friction coefficient and wear rate of $Al_2O_3-TiC$.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.627-628
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• 2006

The present work is a study on the argon gas pressure effects of Sinter/HIP sintering on microstructure and strength of different grades of TiC-NiMo cermets. Titanium carbide in the composition of different grades of TiC-NiMo cermets was ranged from 40 to 80 wt.% and the ratio of nickel to molybdenum in the initial powder composition was 1:1, 2:1 and 4:1 respectively. On the sintered alloys, the main strength characteristic, transverse rupture strength (TRS) was measured. Furthermore, the microstructure parameters of some alloys were measured and the pressure effect on pore elimination was evaluated. All the results were compared with common, vacuum sintered alloys. The TRS values of TiC-NiMo cermets could be considerably improved by using Sinter/HIP technique, for high-carbide fraction alloys and for alloys sintered at elevated temperatures.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.644-645
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• 2006

TiC-and Ti(C,N)-based cermets are excellent in semi-and final finishing of work piece during cutting operations. Typical microstructure of the cermets is a core/rim structure. The undissolved Ti(C,N) cores contribute to their high hardness while the rim phases, (Ti,M1,M2)(C,N)-type solid solutions, play great roles in enhancing the toughness. In this paper, various ultrafine pre-mixed MeC-Ni powders were synthesized and the powders were sintered or hot pressed after mixing in order to control the size and volume fractions of core and rim phases in the system. This paper will present the factors determining the microstructure along with mechanical properties.

• 공업화학
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• 제8권4호
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• pp.589-594
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• 1997

화학증착법을 통하여 $650^{\circ}C$의 증착온도와 0.0126Torr의 산소분압인 증착조건에서 원료물질로 $\beta$-diketonates 킬레이트 화합물을 사용하여 Si(111) 및 $SrTiO_3(100)$ 기판에 $YBa_2Cu_3O_y$ 고온 초전도 박막을 제조하였다. $SrTiO_3(100)$기판에서 제조된 박막의 $T_{c,onset}$과 $T_{c.0}$는 각각 91K와 87K로 나타났다. 또한, Si(111)기판에서 제조된 박막의 $T_{c,onset}$은 91K였지만 $T_{c.0}$는 액체질소 비등점(77.3K)에서는 보이지 않았다. $SrTiO_3(100)$에 증착된 초전도 박막은 치밀하고 2차원적으로 배열된 미세구조를 갖고 있는 반면, Si(111)에 증착된 초전도 박막은 상대적으로 기공이 많으며 무질서한 미세구조를 형성하였다.

• 한국재료학회지
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• 제9권2호
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• pp.168-172
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• 1999

보른이 고농도 도핑된 $\textrm{p}^{+}$-Si 영역상에서 비저항이 낮고 열적 안정성이 우수한 Co/Ti 이중막 실리사이드의 형성을 연구하였다. 본 연구에서는 Co/Ti 이중막 실리사이드는 청결한 $\textrm{p}^{+}$-Si 기판상에 Co(150${\AA}$)/Ti(50${\AA}$) 박막을 E-beam 기술로 진공증착하고 질소분위기($\textrm{10}^{-1}$atm)에서 2단계 RTA 공정(1차열처리:$650^{\circ}C$/20sec, 2차열처리:$800^{\circ}C$/20sec)을 수행하여 제작된다. 실험에서 얻어진 Co/Ti 이중막 실리사이드는 약 500${\AA}$의 균일한 두께를 갖고 18$\mu\Omega$-cm의 낮은 비저항 특성을 나타내었으며, $1000^{\circ}C$에 이르기까지 장시간 후속 열처리를 실시하여도 면저항 변화나 열응집 현상이 발생되지 않았다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.329-332
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• 1989

Lead titanate thin films were deposited on titanium substrates by a chemical vapour deposition(CVD) process involving the application of vapour mixtures of Pb, ethyl titanate( Ti($C_2H_5O_4$)), and oxygen. The lead titanate having a stoichiometric composition has a dc conductivity of $3.2{\times}10^{-12}{\Omega}^{-1}{\cdot}cm^{-1}$ at room temperature. The nonsaturating loops observed in present investigation may be attributed to the $TiO_2$ and TiO layers between the conductive substrate and the $PbTiO_3$ ferroelectric film. The ferroelectric properties of the stoichiometric $PbTiO_3$ film included a remanent polarization of 14.1 ${\mu}C/cm^2$ and a coercive field of 20.16 kV/cm.

• 한국재료학회지
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• 제15권5호
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• pp.318-322
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• 2005

Ti-capped NiSi contacts were formed on $p^+/n$ junctions to improve the leakage problem and then Cu was deposited without removing the Ti-capping layer in an attempt to utilize as a diffusion barrier. The electrical characteristics of these $p^+/n$ diodes with Cu/Ti/NiSi electrodes were measured as a function of drive-in RTA(rapid-thermal annealing) and silicidation temperature and time. When drive-in annealed at $900^{\circ}C$, 10 sec. and silicided at $500^{\circ}C$, 100 sec., the diodes showed the most excellent I-V characteristics. Especially, the leakage current was $10^{-10}A$, much lower than reported data for diodes with NiSi contacts. However, when the $p^+/n$ diodes with Cu/Ti/NiSi contacts were furnace-annealed at $400^{\circ}C$ for 40 min., the leakage current increased by 4 orders. The FESEM and AES analysis revealed that the Ti-capping layer effectively prohibited the Cu diffusion, but was ineffective against the NiSi dissociation and consequent Ni diffusion.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.211-211
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• 1999

Titanium nitride (TiN) thin films have useful properties including high hardness, good electrical conductivity, high melting point, and chemical inertness. The applications have included wear-resistant hard coatings on machine tools and bearings, decorative coating making use of the golden color, thermal control coatings for widows, and erosion resistant coatings for spacecraft plasma probes. For all these applications as feature sizes shrink and aspect ratios grow, the issue of good step coverage becomes increasingly important. It is therefore essential to manufacture conformal coatings of TiN. The growth of TiN thin films by chemical vapor deposition (CVD) is of great interest for achieving conformal deposition. The most widely used precursor for TiN is TiCl4 and NH3. However, chlorine impurity in the as-grown films and relatively high deposition temperature (>$600^{\circ}C$) are considered major drawbacks from actual device fabrication. To overcome these problems, recently, MOCVD processes including plasma assisted have been suggested. In this study, therefore, we have doposited Ti(C, N) thin films on Si(100) and D2 steel substrates in the temperature range of 150-30$0^{\circ}C$ using tetrakis diethylamido titanium (TDEAT) and titanium isopropoxide (TIP) by pulsed DC plamsa enhanced metal-organic chemical vapor deposition (PEMOCVD) method. Polycrystalline Ti(C, N) thin films were successfully grown on either D2 steel or Si(100) surfaces at temperature as low as 15$0^{\circ}C$. Compositions of the as-grown films were determined with XPS and RBS. From XPS analysis, thin films of Ti(C, N) with low oxygen concentration were obtained. RBS data were also confirmed the changes of stoichiometry and microhardness of our films. Radical formation and ionization behaviors in plasma are analyzed by optical emission spectroscopy (OES) at various pulsed bias and gases conditions. H2 and He+H2 gases are used as carrier gases to compare plasma parameter and the effect of N2 and NH3 gases as reactive gas is also evaluated in reduction of C content of the films. In this study, we fond that He and H2 mixture gas is very effective in enhancing ionization of radicals, especially N resulting is high hardness. The higher hardness of film is obtained to be ca. 1700 HK 0.01 but it depends on gas species and bias voltage. The proper process is evident for H and N2 gas atmosphere and bias voltage of 600V. However, NH3 gas highly reduces formation of CN radical, thereby decreasing C content of Ti(C, N) thin films in a great deal. Compared to PVD TiN films, the Ti(C, N) film grown by PEMOCVD has very good conformability; the step coverage exceeds 85% with an aspect ratio of more than 3.

• 대한치과보철학회지
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• 제47권1호
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• pp.39-45
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• 2009

연구목적: 최근 치과용 임플란트의 임상 경향이 전체 치료기간을 줄일 수 있는 방법에 관심이 집중됨에 따라 불활성의 티타늄 임플란트 표면에 활성을 부여하기 위한 다양한 표면처리 방법이 검토되고 있다. 본 연구에서는 높은 강도가 요구되는 부위의 임플란트 재료로서 사용되고 있지만 표면 특성이 순 티타늄에 비해 떨어지는 Ti-6Al-4V 합금의 골전도성을 개선할 목적으로 시행되었다. 연구 재료 및 방법: $20{\times}10{\times}2\;mm$의 Ti-6Al-4V 합금판을 준비한 다음 $TiO_2$ 나노튜브를 형성하기 위해 DC 정전원 장치의 양극과 음극에 각각 시편과 백금판을 결선하고 0.5 M $Na_2SO_4$와 1.0 wt% NaF를 함유하는 전해액을 사용하여 전압 20 V와 전류밀도 $30\;㎃/cm^2$ 조건에서 2시간 동안 양극산화 처리하였다. $TiO_2$ 나노튜브 형성 후 산화 피막층의 결정화를 유도하기 위해 $600^{\circ}C$에서 2시간 동안 열처리하였고, 표면활성도를 개선하기 위해 0.5 M $Na_2HPO_4$ 수용액 24시간 침적과 $Ca(OH)_2$ 포화 수용액에 5시간 침적을 시행하였다. 준비한 시편의 표면 반응성을 조사하기 위해 pH와 무기이온의 농도를 사람의 혈장과 유사하게 조절한 Hanks 용액 (H2387, Sigma Chemical Co., USA)에 2주간 침적하였다. 결과: 20 V에서의 양극산화처리로 직경 48.0 - 65.0 ㎚ 범위의 무정형의 $TiO_2$ 나노튜브가 전체 표면에 걸쳐서 균일하게 생성되는 양상을 보였다. $TiO_2$ 나노튜브는 $600^{\circ}C$에서 2시간 열처리 후 상대적으로 강한 anatase 피크와 함께 rutile 피크가 관찰되었다. $TiO_2$ 나노튜브의 표면활성도는 0.5 M $Na_2HPO_4$ 수용액 24시간 침적과 $Ca(OH)_2$ 포화수용액에 5시간 침적으로 개선되었다. 열처리와 전석회화 처리 후 SBF에 침적한 결과, $TiO_2$ rutile 피크의 상대적 강도는 크게 증가되었지만 HA의 석출은 저하되는 경향을 보였다. 결론: 이상의 결과로 미루어 볼 때, 양극산화 처리한 $TiO_2$ 나노튜브는 $600^{\circ}C$에서의 열처리에 의해 피막층이 안정화되고, 0.5 M $Na_2HPO_4$ 수용액 24시간 침적과 $Ca(OH)_2$ 포화수용액에 5시간 침적으로 표면에 인산칼슘층을 형성하는 것이 표면활성도를 개선하는데 유효함을 알 수 있었다.

• 한국재료학회지
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• 제13권3호
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• pp.200-204
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• 2003

A statistical experiment method was employed to investigate the window of the thermal stability of $TiSi_2$films which are popular for Ti-salicide and ohmic layers. The statistical experimental results showed that the first order term of $TiSi_2$thickness and annealing temperature was acceptable as a function of $\Delta$resistivity by 95% reliability criteria, and R-sq value implying a fit accuracy of the model also showed a high value of 93.80%. We found that $\Delta$resistivity of the $TiSi_2$film annealed at $700^{\circ}C$ for 1 hr changed from 3.35 to $0.379\mu$$\Omega$$\cdot$cm with increasing thickness from 185 to $703\AA$, and TEX>$\Delta$resistivity of the $TiSi_2$film with a fixed thickness of 444 $\AA$ changed from 0.074 to 17.12 $\mu$$\Omega$$\cdot$cm with increasing temperature increase from 600 to $800^{\circ}C$. From these results, we report that the process conditions of$ 692^{\circ}C$-1 hr, $715^{\circ}C$-1 hr, and 73$0^{\circ}C$-1 hr for $TiSi_2$($400 \AA$) are stable by the criteria of 1, 2, and 3 $\mu$$\Omega$$\cdot$cm of $\Delta$resistivity, respectively.