• 열처리공학회지
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• 제18권5호
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• pp.281-287
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• 2005

Titanium aluminium nitride((TiAl)N) film is anticipated as an advanced coating film with wear resistance used for drills, bites etc. and with corrosion resistance at a high temperature. In this study, (TiAl)N thin films were deposited both at room temperature and at elevated substrate temperatures of 573 to 773 K by using a two-facing-targets type DC sputtering system in a mixture Ar and $N_2$ gases. Atomic compositions of the binary Ti-Al alloy target is Al-rich (25Ti-75Al (atm%)). Process parameters such as precursor volume %, substrate temperature and Ar/$N_2$ gas ratio were optimized. The crystallization processes and phase transformations of (TiAl)N thin films were investigated by X-ray diffraction, field-emission scanning electron microscopy. The microhardness of (TiAl)N thin films were measured by a dynamic hardness tester. The films obtained with Ar/$N_2$ gas ratio of 1:3 and at 673 K substrate temperature showed the highest microhardness of $H_v$ 810. The crystallized and phase transformations of (TiAl)N thin films were $Ti_2AlN+AlN{\rightarrow}TiN+AlN$ for Ar/$N_2$ gas ratio of 1:3, $Ti_2AlN+AlN{\rightarrow}TiN+AlN{\rightarrow}Ti_2AlN+TiN+AlN$ for Ar/$N_2$ gas ratio of 1:1 and $TiN+AlN{\rightarrow}Ti_2AlN+TiN+AlN{\rightarrow}Ti_2AlN+AlN{\rightarrow}Ti_2AlN+TiN+AlN$ for Ar/$N_2$ gas ratio of 3:1. The above results are discussed in terms of crystallized phases and microhardness.

• 한국세라믹학회지
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• 제32권7호
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• pp.809-816
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• 1995

Ti1-xAlxN films were successfully deposited on high speed steel and silicon wafer by plasma-assisted chemical vapor deposition using a TiCl4/AlCl3/N2/Ar/H2 gas mixture. Plasma process enabled N2 gas to nitride AlCl3, which is not possible in sense of thermodynamics. XPS analyses revealed that the deposited layer contained Al-N bond as well as Ti-N bond. Ti1-xAlxN films were polycrystalline and had single phase, B1-NaCl structure of TiN. Interplanar distance, d200, of (200) crystal plane of Ti1-xAlxN was, however, decreased with Al content, x. Al incorporation into TiN caused the grain size to be finer and changed strong (200) preferred orientation of TiN to random oriented microstructure. Those microstructural changes with Al addition resulted in the increase of micro-hardness of Ti1-xAlxN film up to 2800Kg/$\textrm{mm}^2$ compared with 1400Kg/$\textrm{mm}^2$ of TiN.

• 한국재료학회지
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• 제10권6호
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• pp.398-402
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• 2000

유도 용해후 열기계적 처리를 거친 3종류의 $Al_3Ti-Cr합금, 즉 Al_{67}Ti_{25}Cr_8,\;Al_{66}Ti_{24}Cr_{10}$ 및 Al_{59}Ti_{26}Cr_{15}에 대해 2.5% NaCl 용액 내에 부삭시험과 1000, 1100 및 $1200^{\circ}C$에서의 고온 산화시험을 실시하였다. 전기화학적 평가결과에서 Cr조성이 증가함에 따라 국부부식에 대한 내식성이 증가하였으며, 부동태 피막의 취성파괴를 방지하였다. XPS결과는 $Al_3Ti-Cr$합금의 부동태 피막은 주로 $Al_2O_3$로 구성되어 있으며, $TiO_2$ 및 $Cr_2O_3$도 공존하고 있음을 알 수 있었다. 고온 내산화성은 모든 시편이 전체적으로 뛰어난 내산화성을 지니고 있었는데, 구체적으로는 $Al_{59}Ti_{26}Cr_{15},\;Al_{66}Ti_{24}Cr_{10}\;및\;Al_{67}Ti_{25}Cr_8$의 순으로 증가하였다. 이는 합금내의 Al 함량이 증가할수록 $Al_2O_3$보호피막의 형성이 용이하였기 때문이었다.

• 한국세라믹학회지
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• 제38권3호
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• pp.225-230
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• 2001

저전압용 형광체로 주목받고 있는 SrTiO$_3$:Pr,Al 형광체를 고상반응법으로 제조하였다. 부활성체 Al이 23 mol% 첨가되었을 때 SrTiO$_3$:Pr 형광체는 최대 발광 강도를 보여주었다. 최대 발광 강도를 보인 형광체에 대해 제한시야회절상과 투과전자현미경을 이용하여 SrTiO$_3$:Pr,Al 적색 형광체내 2차상 형성에 대한 연구를 행하였고 또한 에너지 분산 분광 분석을 행하여 SrTiO$_3$:Pr,Al 형광체내 주입된 부활성제 Al의 함량을 결정하였다. 제한시야회절상의 결과에 의하면 SrTiO$_3$:Pr,Al 적색 형광체내에 단사정 SrAl$_2$O$_4$, 삼사정 Ti$_4$O$_{7}$, 육방정 SrAl$_{12}$O$_{19}$가 2차상으로 존재함을 보여 주었다. 에너지 분산 분광 분석 결과 부활성제 Al의 함량 중 일부는 SrTiO$_3$:Pr,Al 적색 형광체 격자에 고용되고 일부 Al은 SrAl$_{12}$O$_{19}$와 SrAl$_2$O$_4$의 2차상을 형성하는데 소모됨을 보여주었다.주었다.

• 열처리공학회지
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• 제9권1호
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• pp.1-11
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• 1996

Mechanical alloying is an effective process to finely distribute inert dispersoids in an Al-TM(TM is a transition metal) system. It has been considered that high melting point aluminides are formed by precipitation from supersaturated Al(Ti) powder. This analysis is based on the fact that much higher content of TM than the solubioity can be dissolved in alpha aluminum during the high energy ball milling. Thus, decomposition behavior of Ti in the Al(Ti) was considered very important. But it is confirmed that the higher portion of Ti than Al(Ti) solid solution is existed as nano-sized Ti particles in the MA powders by high energy ball nilling from the XRD spectrum and TEM analysis in this study. Therefore, the role of undissolved TM particles affect the formation of aluminides should be suitably considered. In this study, we present experimental observation on the formation of $Al_3Ti$ fron mechanical alloyed Al-Ti alloys in the hyperperitectic region. This study showed that, in the mechanically alloyed Al-20wt%Ti specimen, intermediate phase of cubic $Al_3Ti$ and tetragonal $Al_{24}Ti_8$ formed at $300{\sim}400^{\circ}C$ and $400{\sim}500^{\circ}C$, respectively, before the MA state reaches to equilibrium at higher temperatures. The formation behavior of $Ll_2-Al_3Ti$ is interpreted by interdiffusion of Al and Ti in solid state based on the fact that large amount of nano-sized Ti particles exist in the milled powder. Present analysis indicated undissolved Ti particles of nanosize should have played an important role initiation the formation of $Al_3Ti$ phase during annealing.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.114-115
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• 2013

$Ti_3AlC_2$ was corroded between 800 and $1100^{\circ}C$ in an Ar-0.2% $SO_2$ gas atmosphere according to the equation: $Ti_3AlC_2+O_2{\rightarrow}rutile-TiO_2+{\alpha}-Al_2O_3$ + (CO or $CO_2$). The scales that formed on the $Ti_3AlC_2$ were thin and rich in ${\alpha}-Al_2O_3$, whose growth rate was exceedingly slow. The $TiO_2$ was present either as the outermost surface scale or a mixture inside the ${\alpha}-Al_2O_3$-rich scale. In the $Ti_3AlC_2$, the activity and diffusivity of Ti were low, whereas those of Al were high. This was the main reason for the superior corrosion resistance of $Ti_3AlC_2$ over TiAl.

• 열처리공학회지
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• 제10권2호
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• pp.138-149
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• 1997

TiN and AlN are ceramic materials with extensive applications due to its excellent mechanical and chemical properties at elevated temperature. The purpose of this research is to develop the method for the synthesis of ternary nitride powder, titanium-aluminum-nitrogen system, which have an excellent property of both TiN and AlN. The ternary nitride such as $Ti_3AlN$, $Ti_2AlN$ and $Ti_3Al_2N_2$ can be synthesized by the interdiffusion nitriding method in Ar gas, however, the ternary nitride coexist with TiN, AlN, $Ti_3Al$ and ${\alpha}$-Ti. The ternary nitride are stable below $1400^{\circ}C$, but these are gradually decomposed into TiN, $Ti_3Al$ and AlN above $1400^{\circ}C$. The thermal oxidation characteristics of the Ti-Al-N compound synthesized by the interdiffusion nitriding method is superior to that of the TiN+AlN mixed powder, and the oxidation for both materials show the differential behaviors.

• 한국세라믹학회지
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• 제39권4호
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• pp.413-419
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• 2002

$Al_2O_3$/TiC/SiC, $Al_2O_3$/SiC 및 $Al_2O_3$/TiC 복합체들을 고온가압소결로 제조하여 이들의 균열저항거동과 기계적 성질을 비교해 보았다. $Al_2O_3$에 $0.8{\mu}m$의 TiC가 30vol% 첨가된 $Al_2O_3$/TiC는 단일체 $Al_2O_3$와 비슷한 균열저항거동을 보이며 파괴인성은 전반적으로 10% 이내의 증가를 보이는데 그쳤지만 강도는 약 30% 증가하였다. $Al_2O_3$에 $3{\mu}m$ SiC가 30vol% 첨가된 $Al_2O_3$/SiC는 SiC 입자의 균열 접속으로 인해 증가하는 균열저항거동을 뚜렷이 보이면서 파괴인성이 긴 균열에서 약 75% 증가하였으나 강도는 다소 감소했다. $Al_2O_3$/TiC에 SiC 입자가 30 vol% 첨가된 $Al_2O_3$/TiC/SiC 복합체의 경우 단일체 $Al_2O_3$에 비해 긴 균열 거리에서 파괴인성이 50% 이상 증가된 6.6 MP${\cdot}\sqrt{m}$에 이르렀으며 강도 값도 약 20% 상승하였다. 그러나 큰 SiC 입자의 첨가로 인해 TiC 입자만 첨가된 $Al_2O_3$/TiC 복합체보다는 강도가 다소 낮았다. 또한 SiC 입자만 첨가된 $Al_2O_3$/SiC 복합체보다는 파괴인성이 다소 낮았는데, 이는 작은 TiC 입자들이 SiC 입계를 거칠게 만들어 균열접속을 일으키는 SiC 입자의 뽑힘 현상을 방해하였기 때문이다.

• 자원리싸이클링
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• 제33권1호
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• pp.22-30
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• 2024

2차원 물질 MXene의 전구체로 사용되는 Ti₃AlC₂ MAX 상 합성을 위해, 출발물질로써 타이타늄 (Ti) 스크랩을 활용하는 것은 경제적인 접근이 될 수 있다. 본 연구는 Ti 스크랩을 활용하여 Ti₃AlC₂ MAX상의 상분율 향상을 위한 합성 조건의 최적화를 수행하였다. Ti 스크랩으로부터 수소화-탈수소화(hydrogenation-dehydrogenation, HDH) 공정에 의해 제조된 Ti 분말의 산소 함량은 고상탈산(Deoxidation in solid state, DOSS) 공정을 통하여 효과적으로 감소되었다. 최적 합성 조건은 25 ~ 32 ㎛의 DOSS-Ti, Al, graphite 분말을 3:1.1:2의 몰 비율로 혼합하여 합성되었다. 이 때의 Ti₃AlC₂, TiC 및 Al₃Ti의 상분율은 각각 97.25%, 0.93%, 1.82%로 나타났으며, 25 ~ 45 ㎛의 Ti₃AlC₂ MAX 분말의 산소 함량은 4,210 ppm으로 확인되었다.

• The Korean Journal of Ceramics
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• 제5권1호
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• pp.44-49
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• 1999

In order to improve the oxidation resistance of $Ti_3Al$, Ti-25at.%Al composites containing dispersed particles of 15wt.%SiC were prepared by a tubular mixing-spark plasma sintering method. The sintered composites had $Ti_3Al$, SiC, $Ti_5Si_3$ and TiC. The presence of $Ti_5Si_3$ and TiC indicates that some of SiC particles reacted with Ti to from more stable phases. From oxidation tests at 800, 900 and $1000^{\circ}C$ under 1 atm of pure oxygen, it was found that the oxidation rate of Ti3Al was effectively reduced by the addition of SiC. The scale was primarily composed of an outer $TiO_2$ layer having some $Al_2O_3 $islands, an intermediate relatively thick $Al_2O_3 $ layer, and an inner $TiO_2+Al_2O_3+SiO_2$ mixed layer. Beneath the scale, Kirkendall voids were seen.