• 한국표면공학회지
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• 제32권3호
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• pp.356-359
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• 1999

To obtain a biomaterial that has both biological affinity and high mechanical strength, hydroxyapatite granules were implanted into the surface of pure titanium film coated titanium alloy. The film was coated by reactive DC sputtering method on the alloy substrate. Hydroxyapatite granules (32- $38\mu\textrm{m}$ in diameter)were spread over titanium alloy substrate and pressed to implant the granules in the substrate. They can be implanted into substrate under 17MPa at $800^{\circ}C$ for 10minutes. The only tops of the granules were exposed and they were firmly stuck in substrate. The hydroxyapatite implanted titanium alloy composites were expected to be useful for biomaterials as artificial bones and dental roots.

• Journal of Welding and Joining
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• 제18권5호
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• pp.84-89
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• 2000

Friction welding of titanium and aluminium is numerically modeled by the axisymmetric thermal elastic-plastic analysis. In titanium/aluminium friction welding, heat transfers into the titanium substrate to a distance of z=10(mm) on the side of the bondline and into the whole region of the aluminium substrate having the large thermal conductivity. Adjacent to the bondline, $^{\sigma}r\;and\;^{\sigma\theta}$ are tensile in the substrate whose thermal shrinkage is large, and are compressive in the substrate whose thermal shrinkage is small. $\sigma_z$ along the radial direction is large tensile at the periphery of the component. Plastic strain occurs only close to the bondline in the aluminium substrate. In the components of plastic strain, $\varepsilon^p_r\;and\;\varepsilon^p_{\theta}$ have positive values and $\varepsilon^p_r$ has large negative value. However, $\varepsilon^p_r$ is produced not because of the severity of the mechanical restraint condition, but on purpose to satisfy the condition of the volume constant. A plastic work is proposed as a measure to evaluate the mechanical severity. The plastic work is larger in the aluminium substrate than that in the titanium substrate. The mechanical condition is severer in the aluminium substrate.

• 한국세라믹학회지
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• 제23권6호
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• pp.33-36
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• 1986

The $PbTiO_3$is well known materials having remarkable ferroelectric piezoelectric and pyro-electric properties. Thin films of the lead titanite has been successfully fabricated by Chemical Vapor Deposition on the borosilicate glass and titanium substrate. The $PbTiO_3$ thin film deposited on the borosilicate glass using the $PbCl_2$, $TiCl_4$ dry oxygen and wet oxygen at different temperatures (50$0^{\circ}C$-$700^{\circ}C$) grows along the (001) preferred orientation. On the other hand the $PbTiO_3$ thin film deposited on the titanium substrate using the PbO grows along the (101) preferred orientation. Growth orientation of deposited $PbTiO_3$ depends on the reaction species irrespective of substrate materials. Maximum dielectic constant and loss tangent of the $PbTiO_3$ thin film deposited on the titanium substrate are about 90 and 0.02 respectively, . Deposition rates of $PbTiO_3$ deposited on the borosilicate glass and titanium substrate are 10-15 ${\mu}{\textrm}{m}$/hr. Titanium dioxide interlayer formed be-tween $PbTiO_3$ film and titanium substrate material, It improved the adhesion of the film.

• Corrosion Science and Technology
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• 제19권2호
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• pp.51-56
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• 2020

The objective of this study was to improve properties of plasma sprayed HAp layer to titanium substrate by introducing an intermediate layer with two different methods. Before applying Zn doped HAp coating on titanium substrate, an intermediate layer was introduced by titanium plasma spray or titanium anodization. Heat treatments were conducted for some samples after titanium intermediate layer was formed. Zn doped HAp top layer was applied by plasma spraying. Three-point bending test and pull-off adhesion test were performed to determine the adhesion of Zn doped HAp coatings to substrates. Long-term credibility of Zn doped HAp plasma sprayed coatings on titanium was assessed by electrochemical impedance measurements in Hanks' solution. It was found that both titanium plasma sprayed and titanium anodized intermediate layer had excellent credibility. Strong adhesion to the titanium substrate was confirmed after 12 weeks of immersion for coating samples with titanium plasma sprayed intermediate layer. Samples with titanium anodized intermediate layer showed good bending strength. However, they showed relatively poor resistance against pulling off. The thickness of titanium anodized intermediate layer can be controlled much more precisely than that of plasma sprayed one, which is important for practical application.

• 공업화학
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• 제18권5호
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• pp.438-443
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• 2007

본 연구에서는 티타늄 산화막을 상온에서 HCP (hollow cathode plasma) 반응기에 의하여 증착하였다. HCP 반응기에 대한 시뮬레이션 결과, 전극에서의 열 발생에 관계없이 기판 표면에서의 온도분포는 일정하였다. 그리고 전극과의 거리가 증가하면서 기판 표면에서의 유체는 일정한 것으로 나타났으며, 표면 조도는 거리에 따라 감소하였다. 출력이 증가할수록 산소의 조성은 증가하는 것으로 나타났으며, 출력이 240 watt와 반응 거리가 3 cm에서 Ti와 O의 비율이 1 : 2에 가깝게 결합이 이루어졌다.

• Corrosion Science and Technology
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• 제21권5호
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• pp.340-347
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• 2022

In this research, mixed metal oxide (TiO₂, RuO₂) coating was applied to grade 1 titanium as a bipolar plate for polymer electrolyte membrane fuel cell (PEMFC). Electrochemical experiments were carried out in an aqueous solution of pH 3 (H₂SO₄ + 0.1 ppm HF, 80 ℃) determined by DoE. The air was bubbled to simulate a cathode environment. Potentiodynamic polarization test revealed that corrosion current densities of the titanium substrate and MMO-coated specimen were 0.180 µA/cm² and 4.381 µA/cm², respectively. There was no active peak. After potentiostatic experiment, current densities of the titanium substrate and the MMO-coated specimen were 0.19 µA/cm² and 1.05 µA/cm², respectively. As a result of observing the surface before and after the potentiostatic experiment, cracked dried clay structures were observed without corrosion damage. Both the titanium substrate and the MMO-coated specimen could not satisfy the interfacial contact resistance suggested by the DoE. Thus, further research is needed before they could be applied as bipolar plates.

• 한국표면공학회지
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• 제40권3호
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• pp.113-116
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• 2007

Titanium dioxide ($TiO_2$) films were deposited by RF reactive magnetron sputtering on non-alkali glass and single crystal MgO (100) substrate at substrate temperature of $400^{\circ}C$. Micro structures of $TiO_2$ films were investigated by XRD, FE-SEM, and Pole figure measurements. $TiO_2$ films deposited on glass substrate showed preferred orientation of anatase (101), whereas $TiO_2$ films deposited on the MgO single crystal substrate showed hetero-epitaxial anatase (100). $TiO_2$ film grown on MgO substrate showed higher photoctalytic activity than that of glass substrate.

• 한국재료학회지
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• 제12권11호
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• pp.883-888
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• 2002

We investigated the void formation in composite-titanium silicide($TiSi_2$) process. We varied the process conditions of polycrystalline/amorphous silicon substrate, composite $TiSi_2$ deposition temperature, and silicidation annealing temperature. We report that the main reason for void formation is the mass transport flux discrepancy of amorphous silicon substrate and titanium in composite layer. Sheet resistance in composite $TiSi_2$ without patterns is mainly affected by silicidation rapid thermal annealing (RTA) temperature. In addition, sheet resistance does not depend on the void defect density. Sheet resistance with sub-0.5 $\mu\textrm{m}$ patterns increase abnormally above $850^{\circ}C$ due to agglomeration. Our results imply that $sub-750^{\circ}C$ annealing is appropriate for sub 0.5 $\mu\textrm{m}$ composite X$sub-750_2$ process.

• 반도체디스플레이기술학회지
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• 제18권1호
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• pp.32-37
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• 2019

Titanium dioxide ($TiO_2$) is a promising dielectric material in the semiconductor industry for its high dielectric constant. However, for utilization on Si substrate, $TiO_2$ film meets with a difficulty due to the large leakage currents caused by its small conduction band energy offset from Si substrate. In this study, we propose an in-situ plasma oxidation process in plasma-enhanced atomic layer deposition (PE-ALD) system to form an oxide barrier layer which can reduce the leakage currents from Si substrate to $TiO_2$ film. $TiO_2$ film depositions were followed by the plasma oxidation process using tetrakis(dimethylamino)titanium (TDMAT) as a Ti precursor. In our result, $SiO_2$ layer was successfully introduced by the plasma oxidation process and was used as a barrier layer between the Si substrate and $TiO_2$ film. Metal-oxide-semiconductor ($TiN/TiO_2/P-type$ Si substrate) capacitor with plasma oxidation barrier layer showed improved C-V and I-V characteristics compared to that without the plasma oxidation barrier layer.

• 실천공학교육논문지
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• 제6권2호
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• pp.105-110
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• 2014

본 연구에서는 강한 내구성을 지닌 자동차 타이어용 압력센서를 개발하기 위해 박막 물질로서 적용될 티타늄 멤브레인의 기계적 특성이 연구되었다. 제작공정으로 기존의 마이크로 머시닝공정과 적층 공정기술이 동시에 적용되었으며, 티타늄 멤브레인 기반의 압력 센서가 설계, 제조 및 특성화 되었다. 마이크로 머시닝 공정을 통한 티타늄 멤브레인과 기판의 접합 제조과정은 30분 동안의 20 MPa의 압력과 $200^{\circ}C$의 온도과정 후 $24^{\circ}C$에서의 냉각으로 진행된다. 각각의 압력센서 표면은 니켈 도금된 후방전극이 기판 위에 마이크로 소자로 조립되었다. 제작과정에서 발생한 잔류응력을 예측하기 위해 유한요소 해석이 적용되었다. 또한 티타늄 멤브레인의 외부 압력하에서 변형에 의한 처짐이 계산되었다. 제작된 장치의 민감도는 $10.15ppm\;kPa^{-1}$ 였고 이때의 정전용량 변화량은 0.18 pF, 압력 범위는 0-210 kPa 였다.