• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.89-89
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• 1998

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.55-58
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• 2007

Titanum and its alloys have been used as the important materials of eyewear frame due to its light weight, mechanical strength and corrosion resistance. This study investigates hardness and microstructures of titanum alloy groove wires in according with heating time by high frequency induction heating. Because of increase of grain size by the growth of heating time, hardness of ${\beta}-Ti$ has reduced. Hardness of Ti-325 reduced until 2 sec and rapidly increased at 3 sec by high frequency induction heating. It is observed that hardness of Ti-325 reduces by the increase of the grain size until 2 sec and suddenly increased by the development of the detailed ${\alpha}+{\beta}$ lamella at 3 sec.

• Journal of the Korean Ceramic Society
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• v.35 no.1
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• pp.5-10
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• 1998

Mullitization in a multicomponent oxide system(alumina-kaolin-quartz-feldspar-talc) was studied as a function of sintering temperature from 1200 to 1500$^{\circ}C$ based upon a quantitative X-ray diffraction analysis. In the present study mullite grew as wiskers and its formation reaction showed characteristic there stages as follows In the first stage(1255-1295$^{\circ}C$) an appreciable mullitization(nucleation) occurred while corun-dum dissolution into glass (increasing glass content ) limited the rate of the reaction. At 1295-1335$^{\circ}C$ (second state) the reaction was significantly enhanced with a considerable glass consumption and with no appreciable change in corundum content. Finally (above 1335$^{\circ}C$) the reaction rate was attenuated re-markably with an apparent decrease in glass consumption rate. The impingement of mullite whiskers by oth-er whiskers and crystals was speculated to cause mullite growth in thickness direction with a slow growth rate resulting in the diminished reaction rate in the final stage.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.15-18
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• 2007

Titanum and its alloys have been used as the important materials of eyewear frame because of its light weight, mechanical strength and corrosion resistance. This study investigated the characteristics of P-Ti and ${\beta}$-Ti alloys in accordance with joining conditions by electric resistance brazing. Hardness of P-Ti and ${\beta}$-Ti has been reduced because of an increase of grain size by the growth of brazing time. Hardness reduction and reduction area by grain growth were largely appeared in P-Ti than ${\beta}$-Ti.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.5-8
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• 2007

Titanum and its alloys have been used as the important materials of eyewear frame because of its light weight, mechanical strength and corrosion resistance. This study investigated the characteristics of P-Ti and ${\alpha}$+${\beta}$-Ti alloys in accordance with joining conditions by electric resistance brazing. Hardness of P-Ti and ${\alpha}$+${\beta}$-Ti has been reduced because of an increase of grain size by the growth of brazing current. Especially, hardness reduction was largely appeared in P-Ti than ${\alpha}$+${\beta}$-Ti. It was considered that a little decrease of hardness in ${\alpha}$+${\beta}$-Ti was due to formation of detailed ${\alpha}$+${\beta}$ lamella.

• Journal of Welding and Joining
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• v.6 no.3
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• pp.27-36
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• 1988

In fabrication of various welded structures made of high strength steels, the occurence of hydrogen assisted cracking and embrittlement in HAZ is prime importance. The present work was carried out to clarify the effect of chemical compositions, especially B and/or Ti addition on the cold cracking susceptibility and HAZ embrittlement in low crabon equivalent steel. Tests results showed that the addtio of optimum boron content in steel with low Pem value i.e., below 0.20 % was the best way to improve the weldability as well as the mechanicla properties of $60kg/mm^2$ grade quenched and tempered high strength steels.

• Journal of Ocean Engineering and Technology
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• v.11 no.1
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• pp.44-48
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• 1997

During studies of the ripening reaction of titanium oxalate, a new crystalline phase has been found. The crystal system was determined to be orthormbic with space group $C222_1$. The unit cell parameters were refined to a=10.503(2)$\AA$ b=15.509(3)$\AA$ c=9.7000(1)$\AA$. The chemical formula of the crystal is Ti$_{2}$O$_{2}$(C$_{2}$O$_{4}$)(OH)$_{2}$. H$_{2}$O. When heated to temperatures between 31$0^{\circ}C$ and 38$0^{\circ}C$, the material became amorphous. Heated above 41$0^{\circ}C$ converted it into anatase-type titanium dioxide.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.446-446
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• 2014

흑연(graphite)과 티타늄(titanum; Ti) 타겟이 양쪽에 부착되어 있는 비대칭 마그네트론 스퍼터링 장치를 이용하여 Ti이 도핑되어진 다이아몬드상 탄소박막(Ti doped Diamond-like carbon, DLC:Ti)을 증착하였다. 흑연과 티타늄 타겟의 파워는 고정하고 기판에 음의 DC 바이어스를 인가하여 DC 바이어스 변화에 따른 DLC:Ti 박막을 증착하였다. 증착되어진 박막의 음의 DC 바이어스의 변화에 따라 변화되어지는 경도와 마찰계수, 표면의 거칠기, 접촉각 등의 물리적 특성들을 분석하였으며, XPS와 라만등의 분석법을 이용하여 박막의 구조적 특성을 분석하였으며, 패시베이션 층을 위한 전기적 특성등을 평가하여 이들 특성들간에 관계를 고찰하였다.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.52-59
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• 1996

Conventionally, grinding of stainless steel, aluminium ally, copper alloy, and titanum alloy are difficult to obtain the high quality finish, because they have the mechanical properties such as low hardness, high toughness which result in the loading of wheel and the poor surface finish. Inorder to perform the grinding operations for these sorts of materials easily, the discontinuous grinding wheel with multi-porous grooves has newly been developed. The multi-porous grooves were formed during wheel production. This discontinous grinding wheel increases the grinding performance. It is desirable to use the discontinuous grinding wheel when grinding materials wiht high efficiency and accuracy which is impossible by conventional wheels. In this paper, the constructing and manufacturing method of grinding wheel with multi-proous grooves are explained, and the grinding charateristics of discontinuous grinding wheel are also illustrate.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.444-444
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• 2012

본 연구에서는 흑연(graphite)과 티타늄(titanum; Ti) 타겟이 양쪽에 부착되어 있는 비대칭 마그네트론 스퍼터링 장치를 이용하여 Ti가 도핑되어진 탄소(a-C:Ti) 박막을 증착하였다. 흑연 타겟의 파워는 고정하고 Ti 타겟 파워를 증가시켜 탄소 박막내에 Ti의 함량을 증가시켰으며, Ti 금속 함량에 따른 탄소박막의 경도와 마찰계수, 표면의 거칠기, 접촉각 등의 물리적 특성과 비저항 등 전기적 특성을 고찰하였으며, XPS와 라만등을 이용하여 a-C:Ti 박막의 구조적 특성을 고찰하여 Ti 금속 함량에 따른 구조적 특성과 물리적 특성, 전기적 특성과의 관계를 규명하였다.