• 한국재료학회지
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• 제17권8호
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• pp.420-424
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• 2007

Precipitation behavior has been studied in NiTi-based ordered alloy using transmission electron microscopy. The hardness after solution treatment is high in NiTi alloy suggesting the large contribution of solid solution strengthening in this alloy system. However, the amount of age hardening is not large as compared to the large microstructural variations during aging. At the beginning of aging, the $L2_1-type$ $Ni_2AlTi$ precipitates keep a lattice coherency with the NiTi matrix. By longer periods of aging $Ni_2AlTi$ precipitates lose their coherency and change their morphology to the globular ones surrounded by misfit dislocations. Misfit dislocations, which are observed on {100} planes of H-precipitates have the Burgers vector of a <100> with a pure edge type. The lattice misfits of $NiTi-Ni_2AlTi$ system is estimated from the spacings of misfit dislocations to be 1.3% at 1273 K. The lattice misfits decrease with increasing aging temperature in this system.

• 한국수소및신에너지학회논문집
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• 제10권1호
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• pp.1-7
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• 1999

In order to study on the effect of fabrication methods on the changes of hydrogenation properties of FeTi alloy, FeTi samples were prepared using three different methods, i.e., arc melting, mechanical alloying and combination of the two methods. The FeTi prepared by mechanical alloying represented amorphous structure. The hydrogen storage capacity of arc melted FeTi alloy is larger than any other samples. However, FeTi electrode fabricated by mechanical alloying after arc melting showed largest discharge capacity among them.

• 한국주조공학회지
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• 제32권4호
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• pp.177-180
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• 2012

Ti-based bulk metallic glasses with high glass forming ability were developed through a systematic alloy design technique. The main alloy design strategy was the selection of alloying elements that may not be toxic in the human body. The $Ti_{45.0}Cu_{40.1}Zr_{12.7}Si_{2.2}$ alloy could be cast into an amorphous rod with the diameter of 3 mm by a suction casting technique using Cu mold. The compressive strength of the amorphous rod was measured as 1826 MPa. Since the Ti-based amorphous alloys consist of non-toxic elements, they can be widely used as bio-materials and eco-materials with unique and beneficial properties.

• 한국수소및신에너지학회논문집
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• 제14권4호
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• pp.327-334
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• 2003

경수소와 중수소를 사용하여 Ti1.0Mn0.9V1.1합금의 경우 313K와 353 K에서, $Ti_{1.0}Cr1.5V_{1.1}$합금의 경우 313 K와 338K에서 각각 수소 동위체 효과를 조사하였다. 합금의 결정구조, 각 상의 존재량, 격자상수 등은 Rietveld method에 의해 결정되었다. 두 합금 모두 용도에 관계 없이 중수소의 흡장량이 경수소에 비하여 많았고, 이들 합금의 수소 동위체 효과는 LaNis 합금에 비하여 대단히 크게 나타났다. 실험 온도 범위에서 $Ti_{1.0}Mn_{0.9}V_{1.1}$합금의 경수소화물은 중수소화물에 비하여 안정하였고, Ti1.0Cr1.5V1.7합금에 있어서는 중수소화물이 더욱 안정하였다. 또한 $Ti_{1.0}Cr_{1.5}V_{1.7}$합금이 $Ti_{1.0}Mn_{0.9}V_{1.1}$합금보다 많은 량의 경수소와 중수소를 흡장하였다.

• 대한치과기공학회지
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• 제24권1호
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• pp.95-104
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• 2002

For biomedical applications, Ti-X%Zr-Y%Nb-0.2%Pd(X:10$\sim$20, Y:2$\sim$8) alloys not containing harmful Al and V were newly designed, and the effect of alloy composition and heat treatment on the microstructure and mechanical properties was investigated. From the results, it was shown that the mechanical properties were enhanced with the addition of Zr or Nb. The effect of heat treating on room temperature strength was investigated by aging treatment after solution treatment. The mechanical properties of Ti-20%Zr-4%Nb-0.2%Pd alloy aged at 400$^{\circ}C$ for 10hrs was found to be superior to those of the pure Ti and Ti-6%Al-4%V ELI alloy.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.320-325
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• 2000

This study was performed to investigate the electro-chemical-machining (ECM) characteristic of Ni-Ti Shape Memory Alloy (SMA). From the experimental results, we could gain optimal electro-chemical conditions to bound with lesser machining effect and better surface roughness than any other machining methods to workpiece at the same time. At these conditions, current efficiency was, for especially ECM working of Ni-Ti SMA, approximately 100% and high frequency pulse current was detected.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1030-1031
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• 2006

Titanium alloys and Titanium alloy-based particulate composites were synthesized using the blended elemental P/M route. First, processing conditions such as the fabrication of master alloy powder were investigated. Ti-6Al-4V, Ti-5Al-2.5Fe, Ti-6Al-2Sn-4Zr-2Mo, IMI685, IMI829, Timetal 1100 and Timetal 62S, and Ti-6Al-2Sn-4Zr-2Mo/ 10%TiB and Timetal 62S/10%TiB were then synthesized using the optimal processing conditions obtained. The microstructures and mechanical properties such as tensile strength and high cycle fatigue strength were evaluated.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.143-160
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• 1996

The purpose of this study was to evaluate the response in aspect of attachment and growth rate of osteoblasts and growth rate of osteoblasts and human gingival fibroblasts to the commercially pure titanium(CP titanium)and titanium alloy(Ti-6AI-4V) that are used widely as implant materials, and to obtain the basic information to ideal implant materials. In the studly, commercially pure titanium in first test group, titanium alloy(Ti-6AI-4V) in second test group, cobalt-chrome-molybdenum alloy(Co-Cr-Mo alloy) in positive control group, and tissue culture polystyrene plate in negative control group were used. The results of this study were as follows. 1. Bone marrow cells cultured on CP titanium and Ti-6Al-4V showed significantly greater attachment and growth rate(p(0.05) compared to Co-Cr-Mo alloy in each time. 2. There were no significant differences(p>0.05) in attachment and growth rate of bone marrow cells cultured on CP titanium and Ti-6AI-4V or tissue culture plate. 3. Most bone marrow cells cultured on CP titanium, Ti-6Al-4V and tissue culture plate were attached well to each substratum in first 2days, and then, grew at higher growth rate. On the other hand, some cells cultured on Co-Cr-Mo alloy failed to attach in first 2 days, and then, attached cells grew at lower growth rate than other groups. 4. Attachment and growth rates of gingival fibroblasts cultured on CP titanium and Ti-6Al-4V showed no significant differences(p>0.05) compared to Co-Cr-Mo alloy in 2 days, but significantly greater increase(p<0.05) in 5 and 9 days. 5. There were no significantly differences(p>0.05) between growth rates on gingival fibroblasts cultured on CP titanium, Ti-6Al-4V and tissue culture plate in 2 and 5days, but a significant lower growth rate(p<0.05) on CP titanium and Ti-6Al-4V versus tissue culture plate. 6. Some gingival fibroblasts cultured on all specimen groups failed to attach, but attached cells grew well, especially on CP titanium, Ti-GAl-4V and tissue culture plate. 7. There were no significant differences(P>0.05) between growth rates of both bone marrow cells and gingival fibroblasts cultured on CP titanium and Ti-6AI-4V. As a result of this study, both commercially pure titanium and Ti-6AI-4V showed excellent biocompatibility and there was no significant difference in the cellular response to the both metals. Bone marrow cells cultured on each substratum showed significantly greater growth rate and responded sensitively to cytotoxic effects of metal surfaces compared to gingival fibroblasts. Considering cell response to the substrate, it was likely that the composition itself of titanium metals have no significant effect on the biocompatibility. Further study need to be done to evaluate the influence of surface characteristics on cellular responses.

• 분석과학
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• 제5권3호
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• pp.319-325
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• 1992

플라즈마 아크 용해법으로 이론밀도비 99% 이상인 Mo-1.17 Ti-0.18 Zr-0.06 C 잉고트를 제조하였다. 이때 산소함량은 초기 830ppm에서 40ppm으로 감소하였다. 열간단조 후, 50% 냉간 압연하여 두께 2mm의 판재를 만들어 시편으로 사용하였다. Mo 합금판재의 재결정거동을 조사하기 위하여 $800{\sim}2100^{\circ}C$ 구간에서 1시간 동안 등시열처리하였고, $1400^{\circ}C$, $1500^{\circ}C$, $1600^{\circ}C$에서 0~10800sec 동안 등온열처리하였다. 완전한 재결정은 Mo의 경우 $1400^{\circ}C$에서 종료되었으나 Mo 합금의 경우 $1700^{\circ}C$에서 완료되었다. 또한 Mo 합금의 50%-1시간 재결정온도는 약 $1500^{\circ}C$로서 Mo에 비하여 $300^{\circ}C$ 이상 증가된 것을 알 수 있었다. Mo 합금의 재결정에 필요한 활성화에너지는 508kJ/mol이었다.

• 한국재료학회지
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• 제12권8호
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• pp.669-675
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• 2002

CrN film coated by AIP method, improved the mechanical properties (Hardness, Roughness, wear and fatigue) of Ti-6Al-4V alloy. The properties were studied using GXRD, XPS, Hardness, Roughness, wear and fatigue testers. CrN thin film thickness was about 7.5$\mu\textrm{m}$ and grew with (111) orientation. Hardness of CrN thin film was very high (Hv 1390) and roughness of the surface layer was greatly improved (Ra=0.063$\mu\textrm{m}$) compared with matrix alloy (Ra=0.321$\mu\textrm{m}$). Such changes of hardness and roughness could be contributed to improving the wear resistance and fatigue life. Striation like pattern with dimples and voids, a typical fatigue fracture mode, was observed throughout the specimen.