• 한국세라믹학회지
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• 제33권2호
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• pp.223-227
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• 1996

The effect of ZrC and VC addition on the diffusion induced recrystallization (DIR) of TiC-Cr3C2 has been investigated. With in creasing the amount of added ZrC to Cr3C2 the DIR of TiC was suppressed at the begining and then occurred. On the contrary the DIR was accelerated with the addition of VC to Cr3C2 Because the lattice parameters of (Ti, Cr)C and (Ti,V)C are smaller and that of (Ti, Zr)C is larger than that of TiC the lattice parameter of (Ti,Cr,Zr)C is expected to be similar to that of TiC,. The results indicate that the strain energy due to lattice mismatch between TiC and solid-solution carbide is the driving force of the observed energy due to lattice mismatch between TiC and solid-solution carbide is the driving force of the observed DIR.

• 한국결정학회지
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• 제3권1호
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• pp.44-52
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• 1992

Ti(C, N)-Cr3C2계 ceramics 의 소결에 있어 서, 소결 분위기가 소결체의 물성에 미치는 영 향과 Cr3c2월 상변화 현상을 검토하였다. Ti(C, N)-Crsc2 혼합분말을 진공 및 질소 분위기에서 소결할 경우 치밀한 소결체를 얻을 수 있었으나, 아르곤 분위기에서는 치밀한 소결체를 얻을 수 없었다. 이들 소결체의 X-선 회절 분석결과, 진공 분위기에서는 Cr3c2가 CrIC3로 변화하 였으며 질소 및 아르곤 분위기에서는 상변화가 거의 없었다 이는 진공소결시 Ti(C, N)에서 탈질 현상이 일어나고 이에 따라 Cr3c2중의 C의 이동에 의해 CrTCE 상으로 변하며, 따라서 활발 한 Ti 및 Cr의 이동으로 인해 치밀한 소결이 이루어지는 것으로 해석되며 반면 질소분위기에서는,가질 현상이 일어나고 이에 따라 유리탄 소의 생성, 이 유리탄소에 의한 입계 내의 산소 의 제거 및 입계 사이의 유리탄소의 잔존 등의 소결기구에 의해 치밀화가 이루어 지는 것으로 해석된다.

• 한국세라믹학회지
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• 제35권3호
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• pp.231-238
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• 1998

Cr3C2 -dispersed TiC composites were prepared via HPCS(high pressure-self combustion sintering) pro-cess using mixtures of Ti, Cr and a carbon source for the purpose of increasing the facture toughness and sinterability of TiC. In this study the microstructure and properties of the composites were investigated in terms of relation to the carbon source the particle size of Ti and the amount of Cr. It was found that car-bon black was the most effective carbon source among the various carbon sources tested and the reaction was more effective as the particle size of Ti decreased. Among the sintered composites of Ti-C-Cr system the one with 30wt% Cr showed the best physical properties with 0.5% in apparent porosity 98.8% in re-lative density 18.2 GPa in hardness and 4.46 MPa.m1/2 in fracture toughness. In addition it was observed that the lattice constant of TiC decreased gradually with increasing the amount of Cr.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.119-120
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• 2013

공구, 다이몰드 등에 널리 쓰이는 TiC, TiN, CrN, TiCrN, TiAlN 코팅의 산화특성을 비교하기 위하여 $600^{\circ}C-900^{\circ}C$에서 대기중 산화시험을 실시하였다. 내산화성은 (TiC, TiN), TiAlN, TiCrN, CrN 코팅의 순서로 증가하였다. 코팅원소중 Ti는 $TiO_2$로, Cr은 $Cr_2O_3$로, Al은 $Al_2O_3$로 산화되었다.

• 한국재료학회지
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• 제9권10호
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• pp.951-955
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• 1999

$Ll_2$기지에 20 vol.% $\textrm{Cr}_{2}\textrm{Al}$이 석출된 Al-21Ti-23Cr 2상합금은 $1150^{\circ}C$에서는 2상영역에 위치하지만 $1000^{\circ}C$에서는 3상영역에 위치한다. 이러한 점에 착안하여 본 연구에서는 Al-21Ti-23Cr 2상합금의 시효처리시 $800^{\circ}C$ 및 $1000^{\circ}C$이하에서 시효처리하여 $Ll_2$기지에 제3상을 미세하게 석출시켜, 기계적성질을 개선하고자 하였다. Al-21Ti-23Cr 2상합금의 시효처리시 $800^{\circ}C$ 및 $1000^{\circ}C$에서는 $Ll_2$기지부분에 수 $\mu\textrm{m}$ 크기의 제3상이 다량 석출되지만 $600^{\circ}C$이하에서는 제3상이 석출이 관찰되지 않았으며, 제3상의 석출형태는 $1000^{\circ}C$보다 $800^{\circ}C$에서 시효처리할 경우 더욱 미세하게 분포하는 것으로 확인되었다. 시효온도 상승에 따른 Al-21Ti-23Cr 2상합금의 항복강도는 $800^{\circ}C$에서 급격히 증가 후 다시 급격히 감소하는경향을 나타냈으며, 이러한 항복강도의 급격한 증가는 $Ll_2$기지 부분에 수 $\mu\textrm{m}$ 크기의 미세한 제3상이 다량 석출되기 때문에 나타나는 현상으로 판단된다. Al-21Ti-23Cr 2상합금의 시효처리시 $Ll_2$기지에 석출되는 제3상은 TiAlCr으로 확인되엇으며, 이러한 TiAlCr 석출상의 이용은 $Ll_2$기지의 균열전파에 대한 저항성를 향상시켜 합금의 기계적성질의 개선에 매우 효과적일 것으로 판단된다.

• 한국표면공학회지
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• 제47권5호
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• pp.252-256
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• 2014

The TiAlCrSiN film was deposited on the WC-20%TiC-10%Co carbide, and its oxidation behavior was examined at $700-1000^{\circ}C$. It displayed relatively good oxidation resistance owing to the formation of $TiO_2$, $Al_2O_3$, $Cr_2O_3$, and $SiO_2$ up to $900^{\circ}C$. However, at $1000^{\circ}C$, the fast oxidation rate and partial oxidation of WC in the substrate led to the formation of the thick, fragile oxide scale.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.107-107
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• 2016

TiCrAlSiN films were developed in order to improve the high-temperature oxidation resistance, corrosion resistance, and mechanical properties of conventional TiN films that are widely used as hard films to protect and increase the lifetime and performance of cutting tools or die molds. In this study, a nano-multilayered TiAlCrSiN film was deposited by cathodic arc plasma deposition. It displayed relatively good oxidation resistance at $700-900^{\circ}C$, owing to the formation protective oxides of $Al_2O_3$, $Cr_2O_3$, and $SiO_2$, and semiprotective $TiO_2$. At $1000^{\circ}C$, the increased temperature led to the formation of the imperfect oxide scale that consisted primarily of the outer ($TiO_2$,$Al_2O_3$)-mixed scale and inner ($TiO_2$, $Al_2O_3$, $Cr_2O_3$)-mixed scale.

• Bulletin of the Korean Chemical Society
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• 제26권2호
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• pp.233-237
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• 2005

Cyclopentadiene compounds, 2-[CR'R(OMe)]-1,3-Me$_2C_5H_3$ (R, R' = 2,2'-biphenyl, 2) and 2-[CR'R(OSiMe$_3$)]-1,3-Me$_2C_5H_3$ (R, R' = 2,2'-biphenyl, 3; R = ph, R' = ph, 4; R = 2-naphthyl, R' = H, 5) are readily synthesized from 2-bromo-3-methoxy-1,3-dimethylcyclopentene (1). Reaction of the cyclopentadienes with Ti(NMe$_2$)$_4$ in toluene results in clean formation of the cyclopentadienyl tris(dimethylamido)titanium complexes, which are transformed to the trichloride complexes, 2-[CR'R(OMe)]-1,3-Me$_2C_5H_2$}TiCl$_3$ (R, R' = 2,2'-biphenyl, 6) and {2-[CR'R(OSiMe$_3$)]-1,3-Me$_2C_5H_2$}TiCl$_3$ (R, R' = 2,2'-biphenyl, 7; R = ph, R' = ph, 8; R = 2-naphthyl, R' = H, 9). Attempts to form C1-bridged Cp/oxido complexes by elimination of MeCl or Me$_3$SiCl were not successful. X-ray structures of 6, 7 and an intermediate complex {2-[Ph$_2$C(OSiMe$_3$)]-1,3-Me$_2C_5H_2$}TiCl$_2$(NMe$_2$) (10) were determined.

• 열처리공학회지
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• 제7권4호
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• pp.288-297
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• 1994

In this study, lattice parameter, binding energy and microstructures of TiC layer according to the addition of Fe, Cr were investigated in the reactive deposition coating. From the results, the lattice parameters of the TiC layers by using ferro-titanium as a precursor were 4.329~4.339A but the lattice parameters of the TiC layers formed by ferro-titanium and ferro-chromium decreased to 4.316~4.330A. The hardness of the former's was HV(100g) 3,000~3,400kg/mm and the hardness of the latter's was HV (100g) 3,800~3,900. But, regardless of Cr and Fe, the binding energy of TiC layers were 454.75 eV for $Ti2p_{3/2}$ and were 281.85 eV for Cls. Meanwhile, the TiC layers were densified by addition of Fe, Cr and internal defects were reduced Therefore. it can be concluded that the remarkable hardness increment was obtained by the improvement of microstructures of TiC rather than the increase of bond strength or Peierls stress.

• Corrosion Science and Technology
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• 제15권3호
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• pp.129-134
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• 2016

The effects of Ti on the high temperature oxidation of Ni-based superalloys were investigated by cyclic oxidation at $850^{\circ}C$ and $1000^{\circ}C$. The oxide scale formed at $850^{\circ}C$ consists of $Cr_2O_3$, $Al_2O_3$, and $NiCr_2O_4$ layers, while a continuous $Al_2O_3$ layer was formed at $1000^{\circ}C$. The oxidation rate of the alloy with higher Ti content was higher than the alloy with less Ti content at $850^{\circ}C$, possibly due to the increase in the metal vacancy concentration in the $Cr_2O_3$ layer involved by incorporation of $Ti^{4+}$. However, Ti improved the oxidation resistance of the superalloy at $1000^{\circ}C$ by reducing oxygen vacancy concentration in $Al_2O_3$ layer.