• Applied Microscopy
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• 제29권2호
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• pp.255-263
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• 1999

Co/Ti 다층 박막 구조에서 증착 박막의 두께를 조절하여 세 가지 조성의 다층 박막을 형성시키고, 후속 열처리 공정을 진행시키면서, 다층 박막 구조에서의 계면 반응에 의한 미세 구조 변화와 전기, 자기적 특성 변화를 살펴보았다. 1. Co/Ti다층 박막의 계면 반응은 후속 열처리 온도에 따라 다른 양상을 나타냈다. $200^{\circ}C$의 저온에서 열처리 한 Co/Ti 다층 박막의 계면 반응은, 결정질 Co와 Ti을 계면 반응물로 소모시키면서 비정질 층을 성장시키는 비정질화 반응이 활발이 일어났다. 한편, $300^{\circ}C$와 $400^{\circ}C$의 고온에서 열처리한 Co/Ti 다층 박막의 계면 반응은 새로운 화합물 결정질 CoTi상을 형성시키는 결정화 반응이 우세했다. 2. Co/Ti 다층 박막의 미세구조 변화는 계면에서의 비정질화 반응의 정도에 의존하고, 비정질화 반응은 계면의 분율에 따라 다르게 나타났다. 즉, 계면의 분율이 가장 많은 Co 2nm/Ti 2 nm다층 박막에서 초기 증착 단계의 비정질화 반응이 가장 우세하여 다른 두 조성의 Co/Ti 다층 박막의 미세 구조 변화와 차이를 보였다. 3. 저온 열처리에 따른 X-선 회절 피크변화에서 Ti피크의 감소율이 Co피크보다 더 크게 관찰된 것으로부터 Co/Ti 다층 박막의 계면에서의 결정질 Co와 Ti의 확산 반응에서 Ti이 비정질화 반응의 주 확산자로 작용한 것을 알 수 있다. 4. Co/Ti 다층 박막에서, 비정질층의 생성 및 성장에 의해 박막의 전기적 저항이 증가하였다.

• Journal of Periodontal and Implant Science
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• 제29권1호
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• pp.209-231
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• 1999

Even though titanium(Ti) and its alloys are the most used dental implant materials, there are some problems that Ti wears easily and interferes normal osteogenesis due to the metal ions. Ti coated with bioactive ceramics such as hydroxyapatite has also such problems as the exfoliation or resorption of the coated layer, Recent studies on implant materials have been proceeding to improve physical properties of the implant substrate and biocompatibility of the implant surfaces. The purpose of the present study was to examine the physical property and bone tissue compatibility of bioinert nitrides ion plated Ti, Button type specimens(14mm in diameter, 2.32rrun in height) for the abrasion test and cytotoxicity test and thread type implants(3.75mm in diameter, 6mm in length) for the animal experiments were made from Ti(grade 2) and 316LVM stainless steel. Ti specimens were ion plated with TiN, ZrN by the low temperature arc vapor deposition, and the depth profile of the TiN/Ti, ZrN/Ti ion plated surface was examined by Auger Electron Spectroscopy. Three kind of button type specimens .of TiN/Ti, ZrN/Ti and Ti were used for abrasion test, and HEPAlClC7 cells and CCD cells were cultivated for 4 days with the specimens for cytotoxicity test. Thread type implants of TiN/Ti, ZrN/Ti, Ti, 316LVM were implanted on the femur of 6 adult dogs weighing 10kg-13kg. Two dogs were sacrified for histological examination after 45 days and 90 days, and four dogs were sacrified for the removal torque test of the implant') after 90 days. The removal torque force was measured by Autograph (Shimadzu Co., AGS-1000D series, Japan). Abrasion resistance of TiN/Ti was the highest, and that of ZrN/Ti and Ti were followed. The bioinert nitride ion plated Ti had much better abrasion resistance, compared with Ti, In the cytotoxicity test, the number of both cells were increased in all specimens, and there were no significant difference in cytotoxic reaction among all groups (p>0.1), In histological examination, 316LVM showed the soft tissue engagement in interface between the implant and bone, but the other materials after 45 days noted immature new bone formation in the medullary portion along the implant surface, and those after 90 days showed implant support by new bone formation in both the cortical and the medullary portion, The removal torque force of Tilv/Ti showed significantly higher than that of Ti(p(O,05). The difference in removal torque force between TiN/Ti and ZrN/Ti was not significant(p>0.05), and that of 316LVM was lowest among all groups(p<0.05). These results suggest that bioinert nitrides ion plated Ti can resolve the existing problems of Ti and bioactive ceramics, and it may be clinically applicable to human.

• 한국자기학회지
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• 제1권1호
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• pp.25-29
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• 1991

단롤법 급냉응고장치를 이용하여 디스크 표면속도 40m/s로 Sm-Fe-Ti 리본시편을 제작하하고 이의 결정구조 및 자기특성을 조사하였다. 급낸응고상태에서 $Sm_{x}Fe_{100-x-y}Ti_{y}(3.8{\leq}x{\leq}11.5,\;3.8{\leq}y{\leq}19.2)$ 합금은 전 조성에 걸쳐 $TbCu_{7}-type$ 구조의 준안정상이 형성되고 조성에 따라 ${\alpha}-(Fe,\;Ti),\;Fe_{2}Ti$. 비정질 및 $d=2.14{\AA}$에 강한 회절선을 나타내는 미지의 상 등이 존재함을 알 수 있었다. 한편, 급냉응고에 의하여 생성된 이들 $TbCu_{7}-type$ 구조의 준안정상은 $850^{\circ}C$에서 45분간 열처리한 후에도 완전하게 안전상으로 변태되지 않았으나 $SmFe_{11}Ti$ 조성에서는 거의 완전한 변태가 이루어짐을 알 수 있었다. 최적조건($850^{\circ}C{\times}45분$)으로 열처리한 $SmFe_{11}Ti$ 급냉응고리본은 주상인 $ThMn_{12}$ 구조의 경자성상과 연자성상인 $\alpha$-(Fe, Ti) 및 반강자성 $Fe_{2}Ti$ 등으로 구성되어 있었으며, $\alpha$-(Fe, Ti) 및 $Fe_{2}Ti$의 생성은 열처리시 Sm 원자의 증발에 기인한 것으로 판명되었다. 최적조건으로 열처리한 $SmFe_{11}Ti$ 급냉응고리본의 표면 및 내부 조성에 대한 원자비율은 각각 $SmFe_{25.8}Ti_{2.6}$ 및 $SmFe_{11.7}Ti_{1.0}$이었으며, $\alpha$-(Fe, Ti) 및 $Fe_{2}Ti$의 대부분은 리본의 표면층에 존재하는 것으로 관찰되었다.

• 대한치과기공학회지
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• 제30권1호
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• pp.25-31
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• 2008

Cp-Ti and Ti-6Al-4V alloys commonly used dental implant materials, particularly for orthopaedic and osteosynthesis because of its suitable mechanical properties and excellent biocompatibility. This alloys have excellent corrosion behavior in the clinical environment. The first factor to decide the success of dental implantation is sufficient osseointegration and high corrosion resistance between on implant fixture and its surrounding bone tissue. In this study, in order to increase corrosion resistance and biocompatibility of Cp-Ti and Ti-6Al-4V alloy that surface of manufactured alloy was coated with TiN by RF-magnetron sputtering method. The electrochemical behavior of TiN coated Cp-Ti and Ti-6Al-4V alloy were investigated using potentiodynamic (EG&G Co, PARSTAT 2273. USA) and potentiostatic test (250mV) in 0.9% NaCl solution at 36.5 $\pm$ 1$^{\circ}C$. These results are as follows : 1. From the microstructure analysis, Cp-Ti showed the acicular structure of $\alpha$-phase and Ti-6Al-4V showed the micro-acicular structure of ${\alpha}+{\beta}$ phase. 2. From the potentiodynamic test, Ecorr value of Cp-Ti and Ti-6Al-4V alloys showed -702.48mV and -319.87mV, respectively. Ti-6Al-4V alloy value was higher than Cp-Ti alloy. 3. From the analysis of TiN and coated layer, TIN coated surface showed columnar structure with 800 nm thickness. 4. The corrosion resistance of TiN coated Cp-Ti and Ti-6Al-4V alloys were higher than those of the non-coated Ti alloys in 0.9% NaCl solution from potentiodynamic test, indicating better protective effect. 5. The passivation current density of TiN coated Cp-Ti and Ti-6Al-4V alloys were smaller than that of the noncoated implant fixture in 0.9% NaCl solution, indicating the good protective effect resulting from more compact and homogeneous layer formation.

• 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.

• E2M - 전기 전자와 첨단 소재
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• 제8권1호
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• pp.56-63
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• 1995

MESFETs of the Ti/Au and Ti/Pd/Au gate were fabricated on n-type GaAs. Interdiffusion at Schottky interfaces, Schottky contact properties, and MESFET characteristics with heat treatment were investigated. Ti of Ti/Au contact and Pd of Ti/Pd/Au contact acted as a barrier metal against interdiffusion of Au at >$220^{\circ}C$. Pd of Ti/Pd/Au contact acted as a barrier metal even at >$360^{\circ}C$, however, Ti of Ti/Au contact promoted interdiffusion of Au instead of role of barrier metal. As the heat treatment temperature increases, in the case of both contact, saturated drain current and pinch off voltage decreased, open channel resistance increased, and degree of parameter variation in Ti/Au gate was higher than in Ti/Pd/Au gate at >$360^{\circ}C$ Schottky barrier height of Ti/Au and Ti/Pd/Au contacts was 0.69eV and 0.68eV in the as-deposited state, respectively, and Fermi level was pinned in the vicinity of 1/2Eg. As the heat treatment temperature increases, barrier height of Ti/Pd/Au contact increased, however, decreased at >$360^{\circ}C$ in the case of Ti/Au contact. Ideality factor of Ti/Au contact was nearly constant regardless of heat treatment, however, increased at >$360^{\circ}C$ in the case of Ti/Au contact. From the results above, Ti/Pd/Au was stable gate metal than Ti/Au.

• 한국재료학회지
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• 제21권9호
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• pp.509-514
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• 2011

In this study, optical emission spectroscopy was used to monitor the plasma produced during the RF magnetron sputtering of a $BaTiO_3$ target. The intensities of chemical species were measured by real time monitoring with various discharge parameters such as RF power, pressure, and discharge gas. The emission lines of elemental and ionized species from $BaTiO_3$ and Ti targets were analyzed to evaluate the film composition and the optimized growth conditions for $BaTiO_3$ films. The emissions from Ar(I, II), Ba(I, II) and Ti(I) were found during sputtering of the $BaTiO_3$ target in Ar atmosphere. With increasing RF power, all the line intensities increased because the electron density increased with increasing RF power. When the Ar pressure increased, the Ba(II) and Ti(I) line intensity increased, but the $Ar^+$ line intensity decreased with increasing pressure. This result shows that high pressure is of greater benefit for the ionization of Ba than for that of Ar. Oxygen depressed the intensity of the plasma more than Ar did. When the Ar/$O_2$ ratio decreased, the intensity of Ba decreased more sharply than that of Ti. This result indicates that the plasma composition strongly depends on the discharge gas atmosphere. When the oxygen increased, the Ba/Ti ratio and the thickness of the films decreased. The emission spectra showed consistent variation with applied power to the Ti target during co-sputtering of the $BaTiO_3$ and Ti targets. The co-sputtered films showed a Ba/Ti ratio of 1.05 to 0.73 with applied power to the Ti target. The films with different Ba/Ti ratios showed changes in grain size. Ti excess films annealed at $600^{\circ}C$ did not show the second phase such as $BaTi_2O_5$ and $TiO_2$.

• 한국주조공학회지
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• 제30권4호
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• pp.147-150
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• 2010

알루미늄 합금의 미세조직 개량을 위한 목적으로 사용되는 Al-Ti-B 합금계의 미세화제는 재활용 과정에서 붕소(B)의 농축(Agglomeration) 문제 및 Zr, Si, Cr 등을 함유하는 합금에서 미세화 효과가 급격히 감소하는 Poisoning effect 등이 지적되어 왔다. 최근에는 이를 대체할 수 있는 Al-Ti-C 합금계의 미세화제에 대한 연구가 활발한데 이는 TiC가 용탕 내에서 ${\alpha}$-Al의 핵생성처로 직접 작용하는 점에 착안한 것이다. 한편, 이들 Al-Ti-B, Al-Ti-C 계의 미세화제는 그 제조공정에서 $K_2TiF_6$를 이용함에 따라 불소함유 유해가스를 배출하여 환경 문제를 야기하고, 이를 포집/정화하기 위한 추가설비를 요구하게 된다. 따라서 대기 환경 오염 및 경제성 측면에서 유리한 미세화제의 친환경 제조기술에 대한 개발이 필요한 시점이다. 본 연구에서는 $K_2TiF_6$를 사용하지 않고 용탕 내의 자발적 반응을 이용하여 환경 및 경제적 측면에서 유리한 Al-Ti-C 미세화제를 개발하고자 하였다. A3003 합금을 대상소재로 하여 개발된 Al-Ti-C 미세화제와 상용 Al-Ti-B 미세화제의 미세화 도달시간 및 fading 발생 등을 비교하였다. 본 연구를 통하여 개발된 Al-8.6Ti-0.025C 미세화제는 상용 Al-Ti-B 미세화제 보다 적은 첨가량에도 유사한 미세화 성능을 나타내었으며 용탕 유지시간 100분까지도 fading이 발생하지 않는 것을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권7호
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• pp.344-348
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• 2006

The effect of x on microwave dielectric properties of the $(1-x)Mg_4Ta_2O_9-x(TiO_2,\;CaTiO_3,\;SrTiO_3)$ ceramics for microwave components were investigated. All spcecimens prepared by the conventional mixed oxied method and sintered at $1450^{\circ}C$. Microwave dielectric properties of the $(1-x)Mg_4Ta_2O_9-xTiO_2$ ceramics were influenced by $MgTi_2O_5$ phase. Also the microwave dielectric properties of the $(1-x)Mg_4Ta_2O_9-x(TiO_2,\;CaTiO_3,\;SrTiO_3)$ ceramics were dominated with an addition of $CaTiO_3\;and\;SrTiO_3$. The dielectric constant $(\varepsilon_r)$, quality factor $(Q{\times}f_r)$ and temperature coefficient of the resonant frequency $(TCRF,\;\tau_f)$ of the $(1-x)Mg_4Ta_2O_9-x(TiO_2,\;CaTiO_3,\;SrTiO_3)$ ceramics were $12.96\sim70.98,\;5,132\sim186,410GHZ$ and $-35.82\sim+75.96ppm/^{\circ}C$, respectively, and depend on x and addition materials.

• 한국재료학회지
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• 제17권9호
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• pp.484-488
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• 2007

Mo(Ti) alloy and pure Cu thin films were subsequently deposited on $SiO_2-coated$ Si wafers, resulting in $Cu/Mo(Ti)/SiO_2$ structures. The multi-structures have been annealed in vacuum at $100-600^{\circ}C$ for 30 min to investigate the outdiffusion of Ti to Cu surface. Annealing at high temperature allowed the outdiffusion of Ti from the Mo(Ti) alloy underlayer to the Cu surface and then forming $TiO_2$ on the surface, which protected the Cu surface against $SiH_4＋NH_3$ plasma during the deposition of $Si_3N_4$ on Cu. The formation of $TiO_2$ layer on the Cu surface was a strong function of annealing temperature and Ti concentration in Mo(Ti) underlayer. Significant outdiffusion of Ti started to occur at $400^{\circ}C$ when the Ti concentration in Mo(Ti) alloy was higher than 60 at.%. This resulted in the formation of $TiO_2/Cu/Mo(Ti)\;alloy/SiO_2$ structures. We have employed the as-deposited Cu/Mo(Ti) alloy and the $500^{\circ}C-annealed$ Cu/Mo(Ti) alloy as gate electrodes to fabricate TFT devices, and then measured the electrical characteristics. The $500^{\circ}C$ annealed Cu/Mo($Ti{\geq}60at.%$) gate electrode TFT showed the excellent electrical characteristics ($mobility\;=\;0.488\;-\;0.505\;cm^2/Vs$, on/off $ratio\;=\;2{\times}10^5-1.85{\times}10^6$, subthreshold = 0.733.1.13 V/decade), indicating that the use of Ti-rich($Ti{\geq}60at.%$) alloy underlayer effectively passivated the Cu surface as a result of the formation of $TiO_2$ on the Cu grain boundaries.