Poly(o-anisidine) coatings on brass: Synthesis, characterization and corrosion protection

Sudeshna Chaudhari,A.B. Gaikwad,P.P. Patil 한국물리학회 2009 Current Applied Physics Vol.9 No.1

Poly(o-anisidine) (POA) coatings were synthesized on brass by electrochemical polymerization of o-anisidine in aqueous salicylate solution by using cyclic voltammetry. These coatings were characterized by cyclic voltammetry, UV–visible absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The corrosion protection aspects of POA coatings on brass in aqueous 3% NaCl solution were investigated by potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The potentiodynamic polarization measurements show that the POA coating has ability to protect the brass against corrosion. The corrosion potential was about 0.204 V versus SCE more positive for the POA coated brass than that of uncoated brass and reduces the corrosion rate of brass almost by a factor of 800. The corrosion behavior of the POA coatings was also investigated by EIS through immersion tests performed in aqueous 3% NaCl solution. The evolution of the impedance parameters with the immersion time was studied and the results show that the POA acts as a protective coating on brass against corrosion in 3% NaCl solution. The water uptake and delamination area were also determined to further support the corrosion protection performance of the POA coating. Poly(o-anisidine) (POA) coatings were synthesized on brass by electrochemical polymerization of o-anisidine in aqueous salicylate solution by using cyclic voltammetry. These coatings were characterized by cyclic voltammetry, UV–visible absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The corrosion protection aspects of POA coatings on brass in aqueous 3% NaCl solution were investigated by potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The potentiodynamic polarization measurements show that the POA coating has ability to protect the brass against corrosion. The corrosion potential was about 0.204 V versus SCE more positive for the POA coated brass than that of uncoated brass and reduces the corrosion rate of brass almost by a factor of 800. The corrosion behavior of the POA coatings was also investigated by EIS through immersion tests performed in aqueous 3% NaCl solution. The evolution of the impedance parameters with the immersion time was studied and the results show that the POA acts as a protective coating on brass against corrosion in 3% NaCl solution. The water uptake and delamination area were also determined to further support the corrosion protection performance of the POA coating.

3차원 프린팅 기술을 이용한 차폐체 제작 및 유용성 평가

장희민,윤준 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.7

In the medical field, X-rays are essential in the diagnosis and treatment of diseases, and the use of X-rays continues to increase with the development of imaging technology, but X-rays have the disadvantage of radiation exposure. Although lead protection tools are used in clinical practice to protect against radiation exposure, lead is classified as a heavy metal and can cause harmful reactions such as lead poisoning. Therefore, the purpose of this study is to investigate the usefulness of the shield fabricated using materials of FDM (Fused Deposition Modeling) 3D printer. In order to confirm the filament's line attenuation factor, phantoms were fabricated using PLA, XT-CF20, Wood, Glow and Brass, and CT scan was performed. And the shielding sheet of 100 × 100 × 2 ㎜ size was modeled, the dose and shielding rate was measured by using a diagnostic X-ray generator and irradiation dose meter, and the shielding rate with lead protection tools. As a result of the experiment, the CT number of the brass was measured to be the highest, and the shielding sheet was manufactured by using the brass. As a result of confirming with the diagnostic X-ray generator, the shielding rate was increased in the shielding sheet having a thickness of 6 ㎜ upon X-ray irradiation under the condition of 100 kV and 40 mAs. It measured by 90% or more, and confirmed that the shielding rate is higher than apron 0.25 mmPb. As a result of this study, it was confirmed that the shield fabricated by 3D printing technology showed high shielding rate in the diagnostic X-ray region. there was. 최근 의료분야에서 X선은 질병의 진단 및 치료영역에서 필수적으로 요구되며, 영상의학 기술의 발전과 더불어 X선의 이용은 지속적으로 증가하는 추세지만, X선은 방사선 피폭의 단점을 가지고 있다. 방사선피폭을 방어하기 위해 임상에서는 납 방호도구를 사용하지만 납은 중금속으로 분류되어 납중독 등 인체에 유해한 반응을 일으킬 수 있다. 따라서 본 연구는 FDM(Fused Deposition Modeling)방식의 3차원 프린터의 재료를 이용하여 제작한 차폐체의 유용성을 알아보고자 한다. 필라멘트의 선감약계수를 확인하기 위해 PLA, XT-CF20, Wood, Glow, Brass를 이용해 팬텀을 제작 하고, CT scan을 하였다. 그리고 100 × 100 × 2 ㎜ 크기의 차폐 시트를 모델링하고, 진단용 X선발생장치와 조사선량계를 이용하여 선량 및 차폐율을 측정하였으며, 납 방호도구와의 차폐율을 비교하였다. 실험결과 Brass의 CT number가 가장 높게 측정되어 Brass를 이용하여 차폐시트를 제작하였으며, 진단용 X선발생장치로 확인한 결과 100 kV, 40 mAs 조건으로 X선 조사 시 6 ㎜ 두께의 차폐시트에서 차폐율이 90 % 이상으로 측정되어 apron 0.25 ㎜Pb보다 차폐율이 높은 것을 확인하였다. 본 연구의 결과 3차원 프린팅 기술로 제작한 차폐체가 진단용 X선 영역에서 높은 차폐율을 보이는 것을 확인하였으며, 납 방호도구와의 비교를 통하여 납을 대체하여 방사선 방호도구로서의 가능성을 알 수 있었다.

Usefulness Evaluation and Fabrication of the Radiation Shield Using 3D Printing Technology

장희민(Hui-Min Jang),윤준(Joon Yoon) 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.7

최근 의료분야에서 X선은 질병의 진단 및 치료영역에서 필수적으로 요구되며, 영상의학 기술의 발전과 더불어 X선의 이용은 지속적으로 증가하는 추세지만, X선은 방사선 피폭의 단점을 가지고 있다. 방사선피폭을 방어하기 위해 임상에서는 납 방호도구를 사용하지만 납은 중금속으로 분류되어 납중독 등 인체에 유해한 반응을 일으킬 수 있다. 따라서 본 연구는 FDM(Fused Deposition Modeling)방식의 3차원 프린터의 재료를 이용하여 제작한 차폐체의 유용성을 알아보고자 한다. 필라멘트의 선감약계수를 확인하기 위해 PLA, XT-CF20, Wood, Glow, Brass를 이용해 팬텀을 제작 하고, CT scan을 하였다. 그리고 100 × 100 × 2 ㎜ 크기의 차폐 시트를 모델링하고, 진단용 X선발생장치와 조사선량계를 이용하여 선량 및 차폐율을 측정하였으며, 납 방호도구와의 차폐율을 비교하였다. 실험결과 Brass의 CT number가 가장 높게 측정되어 Brass를 이용하여 차폐시트를 제작하였으며, 진단용 X선발생장치로 확인한 결과 100 kV, 40 mAs 조건으로 X선 조사 시 6 ㎜ 두께의 차폐시트에서 차폐율이 90 % 이상으로 측정되어 apron 0.25 ㎜Pb보다 차폐율이 높은 것을 확인하였다. 본 연구의 결과 3차원 프린팅 기술로 제작한 차폐체가 진단용 X선 영역에서 높은 차폐율을 보이는 것을 확인하였으며, 납 방호도구와의 비교를 통하여 납을 대체하여 방사선 방호도구로서의 가능성을 알 수 있었다. In the medical field, X-rays are essential in the diagnosis and treatment of diseases, and the use of X-rays continues to increase with the development of imaging technology, but X-rays have the disadvantage of radiation exposure. Although lead protection tools are used in clinical practice to protect against radiation exposure, lead is classified as a heavy metal and can cause harmful reactions such as lead poisoning. Therefore, the purpose of this study is to investigate the usefulness of the shield fabricated using materials of FDM (Fused Deposition Modeling) 3D printer. In order to confirm the filament s line attenuation factor, phantoms were fabricated using PLA, XT-CF20, Wood, Glow and Brass, and CT scan was performed. And the shielding sheet of 100 × 100 × 2 ㎜ size was modeled, the dose and shielding rate was measured by using a diagnostic X-ray generator and irradiation dose meter, and the shielding rate with lead protection tools. As a result of the experiment, the CT number of the brass was measured to be the highest, and the shielding sheet was manufactured by using the brass. As a result of confirming with the diagnostic X-ray generator, the shielding rate was increased in the shielding sheet having a thickness of 6 ㎜ upon X-ray irradiation under the condition of 100 kV and 40 mAs. It measured by 90% or more, and confirmed that the shielding rate is higher than apron 0.25 mmPb. As a result of this study, it was confirmed that the shield fabricated by 3D printing technology showed high shielding rate in the diagnostic X-ray region. there was.

6:4 황동의 고온산화에 미치는 Sn과 Al의 영향

文載軫,李東馥 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.7

Four different brasses i.e., Cu-39.49%Zn (6:4 brass), Cu-39.11%Zn-0.80%Sn, Cu-38.85%Zn-0.45%Sn-0.47%Al, and Cu-37.68%Zn-0.46%Sn-1.82%Al were oxidized in air at 873, 973, and 1043 K to investigate the effects of Sn and Al on the oxidation behavior of 6:4 brass. The oxidation resistance of 6:4 brass increased with the addition of Sn and Al, The good oxidation resistance obtained in Cu-37.68%Zn-0.46%Sn-1.82%oAl was mainly attributed to the formation of Al_2CuO_4 that formed in the ZnO-rich oxide scale.

Fretting studies on electroplated brass contacts

Elsevier 2018 International journal of mechanical sciences Vol.140 No.-

<P><B>Abstract</B></P> <P>This article describes frictional and electrical contact behaviors of electroplated brass under fretting conditions. Fretting tests using a crossed cylinder configuration are conducted. Cylindrical-type specimens are made of tin-plated and gold-plated brass. The ratio of the maximum tangential force to normal force is calculated. The ratio is 0.85 for the self-mated tin-plated brass and 0.55–0.6 for the self-mated gold-plated brass. The results show that the evolution of the dimensionless electrical resistance can be described with a <I>Kachanov</I>-type damage form. Two parameters, the electrical resistance rate constant and electrical resistance exponent, are determined to describe the evolution of the electrical resistance. The results also reveal that the rate constant is affected by the test temperature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Friction between self-mated gold coatings is lower than that between tin coatings. </LI> <LI> An electrical resistance during fretting evolves exponentially. </LI> <LI> An electrical resistance can be described with a <I>Kachanov</I>-type damage form. </LI> <LI> The evolution rate of the electrical resistance depends on temperature. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

조선후기 王室祭器 鑄成 鍮器匠 연구

장경희(Jang, kyung-hee) 한국조형디자인학회 2006 조형디자인연구 Vol.9 No.2

The Joseon Dynasty, a Confucian state, decided to rule the nation on the principle of courtesy, and the events hosted by the royal family were also conducted according to courtesy (the five courtesy principles). In particular, the sacrificial rites performed by the royal family were a national event to show off the principle of 'loyalty and filial piety'; so, the utensils used in religious services were cast with the nation's full capability. Manufacturing of the utensils used in religious services for the royal family began to be systematized during the rule of King Sejong early in the Joseon Dynasty and the systematization was completed at the time of King Seongjong, who compiled "The National Five Principles of Courtesy." Meanwhile, the utensils used in religious services for the royal family were produced by a temporary government office called "the Competent Authority," which was set up as needed. This thesis aims to analyze an ancient book entitled "the Competent Authority for Ritual Principles" in order to understand the actual state of brass-ware craftsmen mobilized to the temporary government office to cast the utensils used in religious services for the royal family late in the Joseon Dynasty. The following are a summary of the findings. First of all, early in the 17th century, King Gwanghaegun and King Injo established three times a temporary government office called "the Competent Authority for Religious Services utensils" in order to completely prepare the utensils used in religious services for the royal family, which were scattered or destroyed due to the Japanese invasion in 1592. As a result, two kinds of the utensils of such a kind were equipped in 1601 and five kinds in 1605. Moreover, in 1612, about 80 kinds of brass-ware utensils used in religious services were cast, and all the dished needed for the shrine for the founder of the nation, guardian deities of the nation, royal tombs, and shrines for ghosts were entirely equipped. Next, the utensils used in religious services for the royal family were newly produced when the king died and repaired when they were broken or crushed. For example, the utensils used in religious services at the ancestral shrine of the royal family or the guardian deities of the nation would be frequently examined and mended if needed since they were used for each national sacrificial rite (called "an auspicious rite"). When the king or the queen died (there was performed "an evil rite"), a temporary government office called "the Competent Authority for Shrines for Ghosts" was erected and the utensils were newly manufactured so that they might be used for the sacrificial rites performed before the king tombs[mountain tombs] or within the shrines for ghosts. In this regard, a chronological summary of manufacturing processes of the utensils used in religious services for the royal family produced between the 17th century and the 19th century is listed below. First, in the 17th century, a dish used in religious services for the royal family was manufactured by 6-8 brass-ware craftsman deployed to a temporary government office called "the Competent Authority for Shrines for Ghosts(殯殿魂殿都監)." Copper, a material of the utensils, was imported from Japan, and a team of eight brass-ware craftsman manufactured the dish against a drawing created by a painter. Most of the artisans (capital craftsmen, 京工匠) lived in Seoul and their skill was so good that they were continuously mobilized for 10 years. Second, in the 18th century, like in the 17th century, the utensils used in religious services for the royal family were manufactured in a temporary government office "the Competent Authority for Shrines for Ghosts" by about four brass-ware craftsman (government artisans, 官工匠) who belonged to a permanent government office.

Effect of Cure Levels on Adhesion Between Rubber and Brass in the Composites Made Up of Rubber Compound and Brass-Plated Steel Cord

Jeon, Gyung Soo,Seo, Gon 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.3

The adhesion between rubber compound and brass-plated steel cord of rubber-brass composites with different cure levels was investigated in relation to the formation and growth of their adhesion interphase examined with AES spectroscopy. The optimim-cured adhesion sample showed a maximum pullout force, but the pullout forces of samples under-cured and over-cured were low. The adhesion property of under-cured adhesion samples enhanced with humidity aging due to further curing of rubber and supplementary growth of the adhesion interphase. Cure level exhibiting good adhesion was discussed based on the composition and stricture of the adhesion interphase and the crosslinking density of the rubber layer attached to the interphase.

금속표면이 항생제 내성균주의 생육억제에 미치는 영향

김중범,김재광,김현정,조은정,박연준,이혜경 대한임상미생물학회 2018 Annals of clinical microbiology Vol.21 No.4

Background: The aim of this study was to comparatively evaluate the bactericidal effects of copper, brass (copper 78%, tin 22%), and stainless steel against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VREFM), and multidrug-resistant Pseudomonas aeruginosa (MRPA). Methods: The isolates (MRSA, VREFM, MRPA) used in this study were mixed wild type 3 strains isolated from patients treated at Uijeongbu St. Mary’s Hospital in 2017. These strains showed patterns of multidrug resistance. The lyophilized strains were inoculated into and incubated for 24 hr in tryptic soy broth at 35°C. The initial bacterial inoculum concentration was adjusted to 105 CFU/mL. A 100-mL bacterial suspension was incubated in containers made of brass (copper 78%, tin 22%), copper (above 99% purity), and stainless steel at 35°C. Viable counts of bacteria strains were measured for 9 days. Results: In this study, the bactericidal effects of copper and brass on MRSA, VREFM, and MRPA were verified. The bactericidal effect of stainless steel was much weaker than those of copper and brass. The bactericidal effect was stronger on MRPA than on MRSA or VREFM. Conclusion: To prevent cross infection of multidrug resistant bacteria in hospitals, further studies of longer duration are needed for testing of copper materials on objects such as door knobs, faucets, and bed rails. (Ann Clin Microbiol 2018;21:-85)

Morphology Evolution of Mn5Si3 Phase and Effect of Mn content on Wear Resistance of Special Brass

Lifu Bie,Xiaohong Chen,Ping Liu,Tao Zhang,Xiangliu Xu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.4

There is a surge of interests in developing newer materials with special properties and many areas are being explored byseveral groups. We wish to report our findings on the effect of Mn content on the microstructure and tribological behaviorof special brass. With the increase of Mn content in the range of 4–10 wt%, the hardness and wear resistance of the specialbrass were all changed, and the adhesion with abrasion is form the friction behavior, mainly for all brasses. It was observedthat the matrix grain size was the smallest, and the hard phase was precipitated the most when the Mn quantity attained the8 wt% mark. During this period, the brass has the highest hardness and best wear resistance, which results from the grainrefinement and load transferring effect of precipitates. It was characterized by SEM, EDS, XRD, TEM, etc., and the resultsconfirmed that the precipitates were Mn5Si3and its structure was hollow hexagonal prism. The morphology evolution of thehard phase and its growth mechanism have been investigated, analyzed and simulated the nucleation and growth process ofthe Mn5Si3phase based on crystallography. The outcomes also showed that the presence of defects on the {0001} faces wasthe crucial factor for one-dimensional elongated structure of Mn5Si3phase.

Bi 첨가된 무연황동의 고온 연성에 미치는 첨가원소의 영향

장영환,김상식,김인상,한승전 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.7

In the present study, the effects of P and/or Misch metal (Ms) on the microstructure and high temperature tensile behavior of Bi-added, Pb-free brass were examined. It was found that the tensile ductility of Bi-added. Pb-free brass decreased significantly at 300℃. The addition of P and/or Ms, on the other hand, greatly improved elevated temperature tensile ductility of the present alloy. The microstructural observation demonstrated that the formation of Bi film along the α-β, phase boundary. which is the main cause for the low tensile ductility at elevated temperature, was substantially reduced with the addition of P and/or Ms. The retarded Bi film formation was believed to be due to the thermally stable Bi-related compounds formed in Bi-added, Pb-free brass. (Received April 8, 2004)