• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.309-317
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• 2010

The stainless steel wire is extensively used for the orthodontic treatment. But, the stainless steel wire that has commonly superior corrosion resistance has caused hypersensitive reaction or allergy as side effects because of corrosion in the oral environment. For improving the problem of corrosion, we was evaluated the suitability of the duplex stainless steel(DSS) as orthodontic wire through this study. The DSS wire was evaluated the mechanical strength and bio-stability for suitability and bio-compatibility as orthodontic wire. In this work, the DSS and stainless steel(SS) as common use of medical grade were prepared for the tensile strength test. The DSS wire were treated by heat. and Temperature conditions of the heat treatment were $28^{\circ}C$, $500^{\circ}C$, $600^{\circ}C$, $700^{\circ}C$, $800^{\circ}C$, $900^{\circ}C$, respectively. And the DSS wires that treated by heat on the optimum temperature condition were conducted the bending moment test and calculated the S-Max value and the modulus of elasticity. For evaluating the bio stability, each materials were conducted in vitro test for measuring the cell survival rate. The most interesting results was that the tensile strength test of SS wire($8.17\times10^4\;N/mm^2$) and DSS wire($8.05\times10^4\;N/mm^2$) that treated at $500^{\circ}C$ by heat were similar in mechanical strength. In the bio-stability study, the DSS has no cytotoxicity (p=0.05) Thus, we could make a conclusion that the duplex stainless steel wire has vastly superior corrosion resistance was suitable as orthodontic wire.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.120-120
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• 2009

스테인리스강은 내식성이 우수하여 열교환기, 화학플랜트 등 부식환경의 구조물 혹은 파이프에 널리 사용되고 있다. 스테인리스 파이프 제조에 사용되는 용접방법은 주로 GTA 용접이 적용되고 있는데, 이 방법은 용접부 품질은 우수하지만 용접 생산성이 늦은 단점이 있다. 또한 이상스테인리스 등과 같은 특수한 용도의 스테인리스 강은 기존의 용접으로는 용접부 성능 확보가 어렵다. 레이저는 고밀도로 집속되고 직진성이 우수한 일종의 빛으로 용접/절단 등 금속 혹은 비금속의 가공에 널리 사용되고 있다. 레이저 용접의 장점은 비접촉으로 용접이 가능하고, 용접 속도가 매우 빠르고, 용접이 가능한 소재의 종류 혹은 두께의 제약이 적고, 용접부가 작아 변형이 적다는 것이다. 이러한 장점으로 인하여 자동차산업에 적용이 급격히 증가하였으며, 최근에는 다양한 분야에 적용이 추진되고 있다. 본 발표에서는 스테인리스강의 파이프 제조 공정에 레이저용접을 적용하기 위한 기초 연구를 수행하였다. 사용된 소재는 오스테나이트계 및 이상스테인리스강이었으며, 용입특성, 용접부 기계적 특성 등을 알아 보았으며, 열처리에 따른 특성 변화를 평가하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.393-394
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.925-926
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• 2010

• Journal of Ocean Engineering and Technology
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• v.9 no.1
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• pp.152-152
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• 1995

• Journal of Welding and Joining
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• v.26 no.6
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• pp.30-35
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• 2008

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.150-150
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• 2012

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.11a
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• pp.7-8
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• 2000

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.139-140
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• 2010

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.11 s.254
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• pp.1369-1375
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• 2006

In this work, mechanical characteristics of stainless steel diaphragm have been studied as a potential robust substrate and a diaphragm material for micromachined devices. Lamination process techniques combined with traditional micromachining processes have been adopted as suitable fabrication technologies. To illustrate these principles, capacitive pressure sensors based on a stainless steel diaphragm have been designed, fabricated and characterized. The fabrication process for stainless steel micromachined devices keeps the membrane and substrate being at the environment of 8.65MPa pressure and $175^{\circ}C$ for a half hour and then subsequently cooled to $25^{\circ}C$. Each sensor uses a stainless steel substrate, a laminated stainless steel film as a suspended movable plate and a fixed, surface micromachined back electrode of electroplated nickel. The finite element method is adopted to investigate residual stresses formed in the process. Besides, out-of-plane deflections are calculated under pressures on the diaphragm. The sensitivity of the device fabricated using these technologies is 9.03 ppm $kPa^{-1}$ with a net capacitance change of 0.14 pF over a range 0$\sim$180 kPa.