• 한국세라믹학회지
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• 제49권4호
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• pp.333-336
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• 2012

The study to give electrical conductivity by dispersing carbon nanotubes (CNT) into silicon nitride ($Si_3N_4$) ceramics has been carried out in recent years. However, the density and the strength of $Si_3N_4$ ceramics were degraded and CNTs disappeared after firing at high temperatures because CNTs prevent $Si_3N_4$ from densification and there is a possibility that CNTs react with $Si_3N_4$ or $SiO_2$. In order to suppress the reaction and the disappearance of CNTs, lower temperature densification is needed. In this study, $HfO_2$ and $TiO_2$ was added to $Si_3N_4-Y_2O_3-Al_2O_3$-AlN system to fabricate CNT-dispersed $Si_3N_4$ ceramics at lower temperatures. $HfO_2$ promotes the densification of $Si_3N_4$ and prevents CNT from disappearance. As a result, the sample by adding $HfO_2$ and $TiO_2$ fired at lower temperatures showed higher electrical conductivity and higher bending strength. It was also shown that the mechanical and electrical properties depended on the quantity of the added CNTs.

• 열처리공학회지
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• 제22권5호
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• pp.267-274
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• 2009

Titanium Chromium Nitrided (TiCrN) coatings were deposited on stainless steel 316 L and Si (100) wafer by inductively coupled plasma assisted D.C. magnetron sputtering at the various sputtering power on Cr target and $N_2/Ar$ gas ratio. Increasing the sputtering power of Cr target, XRD patterns were changed from TiCrN to nitride $Cr_2Ti$. The maximum hardness was $Hk_{3g}$ 3900 at $0.3\;N_2/Ar$ gas ratio. The thickness of the TiCrN films increased as the Cr target power increased, and it showed over $Hk_{5g}3100$ hardness at 100 W, 150 W. TiCrN films were deposited by the ICP assisted DC magnetron sputtering shown good wear resistance as the $N_2/Ar$ gas ratio was 0.1, 0.3.

• International Journal of Ocean System Engineering
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• 제2권2호
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• pp.106-115
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• 2012

In the present study, TiN and CrN films were coated by arc ion plating equipment onto aluminum alloy substrate, A2024. The film thickness was about 4.65 ${\mu}m$. TiN and CrN films were analyzed by X-ray diffraction and energy dispersive X-ray equipments. The Young's modulus and the micro-Vickers hardness of aluminum substrate were modified by the ceramic film coatings. The difference in Young's modulus between substrate and coating film would affect on the wear resistance. The critical load, Lc, was 75.8 N for TiN and 85.5 N for CrN. It indicated from the observation of optical micrographs for TiN and CrN films that lots of cracks widely propagated toward the both sides of scratch track in the early stage of MODE I. TiN film began to delaminate completely at MODE II stage. The substrate was finally glittered at MODE III stage. For CrN film, a few crack can be observed at MODE I stage. The delamination of film was not still occurred at MODE II and then was happened at MODE III. This agrees with critical load measurement which the adhesive strength was greater for CrN film than for TiN film. Consequently, it was difficult for CrN to delaminate because the adhesive strength was excellent against Al substrate. The wear process, which the film adheres and the ball transfers, could be enhanced because of the increase in loading. The wear weight of ball was less for CrN than for TiN. This means that the wear damage of ball was greater for TiN than for CrN film. It is also obvious that it was difficult to delaminate because the CrN coating film has high toughness. The coefficient of friction was less for CrN coating film than for TiN film.

• 한국산학기술학회논문지
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• 제15권3호
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• pp.1253-1258
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• 2014

CA 이온도금기술에 의한 TiC와 TiN 그리고 TiC/TiN 코팅재를 비교하기 위하여 트라이볼로지 물성을 연구하였다. 실험은 Falex journal V block 시스템을 이용한 터보시험기에서 수행하였다. 코팅재의 마찰과 마모특성은 작용된 하중과 미끄럼 속도에 의하여 다양하게 결정되었다. TiC와 TiN 그리고 TiC/TiN 코팅재는 표면에서 트라이볼로지 특성이 현저하게 증가하였다. 단층코팅에서는 TiC보다 TiN이 좋은 결과를 얻었다. 그러나, TiC/TiN의 다층코팅은 다른 어떤 단층코팅보다 좋은 성능을 보였다. 다층코팅의 성능이 향상된 핵심요소는 TiN층 외부와 강 사이에서 부착이 증가하게된 TiC의 역할 때문이다.

• 한국분말재료학회지
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• 제17권2호
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• pp.142-147
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• 2010

The ultrafine titanium carbonitride ($TiC_xN_y$) particles below 100 nm in mean size, including various carbon and nitrogen contents (x=0.55~0.9, y=0.1~0.5), were successfully synthesized by new Mg-thermal reduction process. Nanostructured sub-stoichiometric titanium carbide ($TiC_x$) particles were initially produced by the magnesium reduction of gaseous $TiCl_4+x/2C_2Cl_4$ at $890^{\circ}C$ and post heat treatments in vacuum were performed for 2 hrs to remove residual magnesium and magnesium chloride mixed with $TiC_x$. Finally, well C/N-controled $TiC_xN_y$ phases were successfully produced by nitrification heat treatment under normal $N_2$ gas atmosphere at $1150^{\circ}C$ for 2 hrs. The values of purity, mean particle size and oxygen content of produced particles were about 99.3%, 100 nm and 0.2 wt.%, respectively.

• Journal of Welding and Joining
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• 제25권2호
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• pp.62-69
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• 2007

A kinetic model fur the particle coarsening behavior was developed. The proposed model considered the critical particle size which can be derived from Gibbs-Thomson equation unlike the conventional approach. In this study, the proposed particle coarsening model was applied to study the coarsening behavior of titanium nitride (TiN particle) in microalloyed steel weld HAZ. Particle size distributions and mean particle size by the proposed model were in agreement with the experimental results. Meanwhile, using additivity rule, the isothermal model was extended to predict particle coarsening behavior during continuous thermal cycle.

• 한국정밀공학회지
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• 제26권8호
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• pp.112-118
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• 2009

A pressure rise is generated while air bearing stages are moving in high vacuum environment. This study analyzed this pressure rise phenomenon theoretically and verified it experimentally using two different kinds of stages - linear and rotary air bearing stages. Results indicate that the pressure rise was caused by additional leakage resulting from stage velocity, along with adsorption and outgassing of gas molecules from the guide rail surface. Though tilting of the stage due to acceleration and deceleration reached several micrometers, it had a negligible effect on pressure rise because the tilting time was very short. Therefore, a rotary air bearing stage showed much less pressure rise than a linear stage because the rotary stage theoretically has nothing to do with the above causes. Additional leakage caused by stage velocity was inevitable if the stage had movements, but pressure rise caused by adsorption and outgassing could be suppressed by improving the surface quality to reduce real surface area, and by coating the guide rail surface with titanium nitride (TiN) which has less adhesion probability of gas molecules. The results also indicate that the pressure rise increased when the air bearing stage operated under high vacuum conditions.

• 한국전기전자재료학회논문지
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• 제21권7호
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• pp.660-664
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• 2008

Titanium nitride (TiN) thin films are widely used for hard coatings due to their superior hardness, chemical stability, low friction and good adhesion properties. In this study, we investigated the effect of DC power on the characteristics of TiN thin films deposited on Si and glass substrates by DC magnetron sputtering using TiN target. We made TiN films of 300 nm thickness with various DC powers. The structural properties of films are investigated by x-ray diffractions (XRD) and tribological properties are measured by nano-indentation, nano-scratch tester. The rms roughness was measured by atomic forced microscopy (AFM). In the result, TiN films had the smooth surface and exhibited (111) directions with the increase of DC Power. Also, especially in case of 175 W DC power, TiN film exhibited the maximum hardness about 8 GPa, and the critical load near 25.

• 한국기계가공학회지
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• 제10권4호
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• pp.96-101
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• 2011

The thin films of TiN have been used extensively as wear-resistant materials, for instance, such as tools of high-speed cutting, metal mold forming etc. In these days, because the thin films capable of being used more severe conditions are needed, the technologies of arc ion plating are tried to improve its characteristics. The purpose of this study is to investigate the characteristics of thin films of (Ti,Cr)N compared with those of TiN. The method of arc ion plating, which is known as showing good tight-adherence and productivity, was used. After manufacturing thin films of ($Ti_{1-x}Cr_{x}$)N (x=0~1) with change of Cr in (Ti,Cr) target, atomic concentration, structure, size of crystallite, residual stress and surface roughness of thin films on substrate were investigated. As the results, it was confirmed that Cr atomic concentrations of thin films were proportionally changed with Cr atomic concentrations of target, and thin films of ($Ti_{1-x}Cr_{x}$)N (x=0~1) showed NaCl type and CrN existed as solid solution to TiN.

• 한국진공학회지
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• 제6권4호
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• pp.314-320
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• 1997

XPS를 이용하여 공기 중에 노출된 TiN박막과 상온 증착된 Cu사이의 계면에서의 화학적 반응과 전자 구조적인 변화를 조사하였다. Ti(2p), O(1s), N(1s), Cu(2p) core-level과 Cu LMM Auger line의 spectrum을 보면, Cu의 증착두께가 증가하여도 peak의 위치 뿐만 아니라 line shape이 전혀 변화하지 않는다. 그리고 XPS에 의한 valence bands를 보아도 전 혀 변화가 없다. 이것은 공기 중에 노출된 TiN박막과 Cu사이의 계면에서 Cu화합물의 어떠 한 형태도 존재하지 않을 뿐만 아니라 전자 구조적인 면에서도 전혀 변화가 없음을 의미한 다. 계면에서 Cu가 화학적 반응을 일으키지 않는 것은 계면접합력을 나쁘게 하는 요인이 된 다. 우리는 계면에서의 화학 반응 또는 전자구조의 변화에 대한 연구를 통하여 Cu와 TiN박 막의 계면접합력을 이해할 수 있었다.