• Journal of the Korean institute of surface engineering
• /
• v.33 no.4
• /
• pp.251-260
• /
• 2000

Ta and Hf added Ti-l5Sn-4Nb alloys without V and Al elements for biomaterial were melted by arc furnace in response to recent concerns about the long term safety of Ti-6Al-4V alloy. All specimens were homogenized at $1000^{\circ}C$ and solution treatment was performed at $812^{\circ}C$ and aging treatment at $500^{\circ}C$. The microstructure and mechanical properties were analysed by optical micrograph, hardness tester and instron. Ti-l5Sn-4Nb system alloys showed widmanstatten microstructure which is typical microstructure in $\alpha$＋$\beta$ type Ti alloys. The Ti-l5Sn-4Nb-2Hf and Ti-l5Sn-4Nb-2Ta alloys showed better hardness and tensile strength compared with Ti-6Al-4V. The result of XPS analysis, Ti-l5Sn-4Nb alloy in air atmosphere consisted of $TiO_2$, SnO and NbO.

• Journal of the Korean Chemical Society
• /
• v.27 no.6
• /
• pp.424-482
• /
• 1983

Determination for $Ta_2O_5$,$Nb_2O_5$ and $SnO_2$ in tin slags was investigated by X-ray spectrometric method. Standard addition-dilution method was attempted and showed a comparable accuracy with standard calibration curve method. Pure chemicals($Ta_2O_5$,$Nb_2O_5$ and $SnO_2$) were added to the samples and diluted with silica or ferric oxide. For the determination of $Ta_2O_5$and$SnO_2$ , silica was more suitable than ferric oxide while the latter was more preferable than the former for $Nb_2O_5$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.2
• /
• pp.81-85
• /
• 2017

$SnO_2/Ag/Nb_2O_5/SiO_2/SnO_2$ multilayer films were prepared on glass substrate by sequential using RF/DC magnetron sputtering at room temperature. The influence of top $SnO_2$ layer thickness on optical and electrical properties of the multilayer films was investigated. Experimentally measured results exhibit transmittances over 84.3 ~ 85.8% at 550 nm wavelength. As the top $SnO_2$ layer thickness increased from 40 to 55 nm, the sheet resistance (Rs) increased from 5.81 to $6.94{\Omega}/sq$. The Haacke's figure of merit (FOM) calculated for the samples with various $SnO_2$ layer thicknesses was a maximum at 45 nm ($35.3{\times}10^{-3}{\Omega}^{-1}$).

• Journal of Technologic Dentistry
• /
• v.23 no.1
• /
• pp.55-64
• /
• 2001

This study is focusing on the improvement of problems of Ti-6Al-4V alloy. A new Ti based alloy, Ti-15Sn-4Nb, have designed to examine any possibility of improving the mechanical properties and biocompatibility. Specimens of Ti alloys were melted in vacuum arc furnace and homogenized at $100^{\circ}C$ for 24h. All specimens were solution treated at $812^{\circ}C$ and aged at $500^{\circ}C$ for 10h. The corrosion resistance of Ti alloys was evaluated by potentiodynamic polarization test and immersion test inl%Lactic acid solutions. Ti-15Sn-4Nb system alloys showed Widmanstatten microstructure after solution treatment which is typical microstructure of ${\alpha}+{\beta}$ type Ti alloys. Analysing the corrosion resistance of Ti alloys, it was concluded that the passive films of Ti-15Sn-4Nb system alloys are more stable than that of Ti-6Al-4V alloys. Also, the corrosion resistance of Ti-15Sn-4Nb system alloys was improved with adding elements, Hf. It was analysed that the passive film of the Ti-15Sn-4Nb alloy which was formed in air atmosphere was consisted of TiO2, SnO and NbO through X-ray photoelectron spectroscopy(XPS) analysis.

• Journal of the Microelectronics and Packaging Society
• /
• v.2 no.2
• /
• pp.31-40
• /
• 1995

Donor dopant로 WO3, Ta2O5 및 Nb2O5를 첨가한 Zr0.8Sn0.2TiO4 세라믹스의 유전상수 $\varepsilon$r 품 질계수 Q 및 공진주파수의 온도계수 rf에 대하여 연구하였다. 139$0^{\circ}C$에서 32시간 소결시 donor dopant 첨가량에 따른 ZST의 유전상수는 소결밀도의 변화 거동과 잘 일치하였다. 5.5 GHz에서 측정 한 ZST의 품질계수 Q는 ~0.5 mol% WO3 Ta2O5 및 Nb2O5 첨가에 의해 6800에서 8500 정도로 증가 하였다. ZST의 $\tau$f는 0.3 mol%까지의 WO3 첨가량 증가에 따라 0 ppm/$^{\circ}C$에서 -4.6 ppm/$^{\circ}C$까지 음 의 값으로 직선적으로 감소하였으며 0.4 mol% 범위의 Ta2O5 및 Nb2O5 첨가에 의해 -7 ppm/$^{\circ}C$ 까지 직선적으로 감소하였다.

• Korean Journal of Materials Research
• /
• v.7 no.9
• /
• pp.772-780
• /
• 1997

Zr-Nb-Sn 의 3원계 합금에서 Sn 함량 변화가 부식에 미치는 영향과 석출물 특성에 미치는 영향을 평가하여 신합금 개발을 위한 Sn의 최적 함유량을 도출하고자 Zr-0.4Nb-xSn(x=0.4,0.8, 1.2, 1.6)계의 4종 합금을 제조하여 여러 가지 특성시험을 실시하였다. 부식특성은 42$0^{\circ}C$ steam(1500psi)조건의 autoclave를 이용하여 시험하였으며 부식과정에서 발생하는 무게증가량을 측정하였고 산화막 특성은 X-ray를 이용하여 조사하였다. 부식관점에서 Sn량이 적을수록 내식성은 증가하는 경향을 보였다. 즉, 0.4Sn합금에서 가장 낮은 무게증가량과 1.6Sn 합금에서 가장 높은 무게 증가량을 보였다. 그러나 수소흡수성면에서는 Sn량이 많을수록 수소흡수율이 작아지는 경향을 보였다. 산화막내에서 tetra-ZrO$_{2}$량은 Sn량이 많을수록 적게 나타나는데, 이같은 결과로부터 Sn량이 많을수록 tetra-ZuO$_{2}$에서 mono-ZrO$_{2}$로의 상변태가 가속되어 Sn이 많이 함유된 합금에서 부식 저항성은 저하된다고 사료된다. Sn량이 증가함에 따라 강도는 점차적으로 증가하는 경향을 보였다. Sn량 변화에 따른 석출물의 특성을 조사한 결과, Zr-0.4Nb-xSn계 합금에서는 Sn이 석출물 형성에 거의 영향을 미치지 않으며, 또한 석출물 크기도 내식성에 커다란 영향을 미치지 않는 것을 확인하였다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.441-442
• /
• 2012

SnNb2O6 nanoplates were prepared by a solvothermal synthesis with water and ethanol mixed solvent. For improvement of their properties, as-prepared SnNb2O6 nanoplates also were calcined. The prepared powder was characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Transmission electron microscope (TEM), UV-vis spectroscopy, Raman spectrometer, Brunauer-Emmett-Teller (BET). The calcined nanoplates have a smaller surface area than the as-prepared nanoplates have. Nevertheless, in the case of the optical absorption properties, the calcined nanoplates could absorb more photon energy, due to their smaller band gaps. The Raman analysis revealed that the Nb-O bond length in the calcined nanoplates was longer than that in the as-prepared nanoplate. The higher optical absorption capability of the calcined nanoplates was attributed to the local structure variation within them. Furthermore the high crystallinity of the calcined nanoplates is effective in improving the generation of charge carriers. So, It was found that the calcined nanoplates exhibited superior photocatalytic activity for the evolution of H2 from an aqueous methanol solution than the as-prepared nanoplates under UV and visible irradiation. Therefore, the enhanced photocatalytic activity of the calcined nanoplate powder for H2 evolution was mainly attributed to its high crystallinity and improved optical absorption property resulting from the variation of the crystal structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1993.11a
• /
• pp.10-13
• /
• 1993

ln this study, x PSN - y PT - z PZ ceramics doped with w MnO$_2$were fabricated by the mixed oxide method at 1250[$^{\circ}C$] for 2[hr] and then the dielectric and pyroelectric properties were investigated. In the 0.05 PSN - 0.4 PT - 0.55 PZ specimen with 0.5[wt.%] MnO$_2$, the pyroelectric coefficient was 6.6${\times}$10$\^$-8/[C/cm$^2$$.$$^{\circ}C$], respectibly.

• Proceedings of the KIEE Conference
• /
• 1994.07b
• /
• pp.1496-1498
• /
• 1994

In this study, x PSN - y PT - z PZ ceramics doped with w $MnO_2$ were fabricated by the mixed oxide method at 1250 [$^{\circ}C$] for 2[hr] and then the dielectric and pyroelectric properties were investigated. In the 0.05 PSN - 0.4 PT - 0.55 PZ specimen with 0.5[wt%] $MnO_2$ the Pyroelectrics coefficient was $6.6{\times}10^{-8}[C/cm^2.^{\circ}C]$, respectibly.

• Proceedings of the KIEE Conference
• /
• 1993.07b
• /
• pp.1119-1121
• /
• 1993

The PSN-PT-PZ ceramics doped with the Mn-oxide(0.5wt%) were fabricated by the mixed oxide method at 1250($^{\circ}C$) for 2(hr) and then the dielectric and pyroelectric properties were investigated with the compositions. In the 0.05PSN-0.4PT-0.55PZ specimen with 0.5(wt%) $MnO_2$, the pyroelectric coefficient was $6.6{\times}10^{-8}(C/Cm^2^{\circ}C)$, and the figure of merits for pyroelectric current and voltage were $27{\times}10^{-9},\;45{\times}10^{-12}$(C.Cm/J), respectibly.