• Corrosion Science and Technology
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• 제4권3호
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• pp.75-80
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• 2005

This work dealt with the evaluation of galvanic corrosion rate in a corrosion cell having annular gap of 0.5 mm between carbon steel 1018 and alloy 600 as a function of temperature and boron concentration. Temperature and boron concentration were ranged from 110 to 300 $^{\circ}C$ and 2000~10000 ppm, respectively. After the operating temperature of the corrosion cell where the electrolyte was injected was attained at setting temperature, galvanic coupling was made and at the same time galvanic current was measured. The galvanic corrosion rate decreased with time, which was described by corrosion product such as protective film as well as boric acid deposit formed on the carbon steel with time. From the galvanic current obtained as a function of temperature and boron concentration, it was found that the galvanic corrosion rate decreased with temperaturewhilethe corrosionrate increasedwith boronconcentration. The experimental resultsobtained from galvanic corrosion measurement were explained by adhesive property of corrosion product such as protective film, boric acid deposit formed on the carbon steel wall and dehydration of boric acid to be slightlysolubleboric acid phase.Moreoverthe galvaniccorrosionrate calculatedusing initialgalvaniccoupling current instead of steady state coupling current was remarked, which could give us relatively closer galvanic corrosion rate to real pressurized water reactor.

• Corrosion Science and Technology
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• 제16권3호
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• pp.128-140
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• 2017

Aluminum alloy matrix may be used for manufacturing lighter automobiles. However, galvanic corrosion may occur between the rivet joint combining aluminum alloy matrix and a CFRP (carbon fiber reinforced plastic) laminate. The possibility of galvanic corrosion may be investigated by measuring galvanic couple currents. Two types of galvanic current measuring methods were used. One method is to use potentiodynamic polarization curves and the other is the ZRA (zero resistance ammeter) method. For galvanic corrosion experiments graphite, a major component of CFRP, was used with carbon steel (rivets) and 6061 aluminum alloys. Regardless of carbon steel, Ni deposited carbon steel, and 316L stainless steels we also investigated the possibility of reduction in galvanic corrosion. Results revealed that even though Ni deposited carbon steel or 316L stainless rivet may slightly increase galvanic current density between those and Al matrix, substitute rivets for carbon steel may be considerably useful for reducing overall galvanic corrosion.

• Restorative Dentistry and Endodontics
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• 제10권1호
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• pp.63-70
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• 1984

It was the purpose of this study to determine the galvanic current between a gold alloy inlay and four types of amalgam using the circuit through pulp chambers when the freshly extracted teeth with those restorations were brought into contact in a physiologic saline solution, and to investigate the effectiveness of cavity varnish or ammonated silver-nitrate on the surface of amalgam restoration in reducing galvanic current. The current was measured with current-to-voltage converter and recored on a physiograph 6630-257. The following results were obtained. 1. Generally, galvanic current decreased as the time elapsed. 2. Galvainc current decreased significantly in the first day and after then minimal change was observed until 30th day. 3. Initial galvanic current was 29.6 ${\mu}A$ in the cut amalgam and 24.5 ${\mu}A$ in Dispersalloy amalgam and after then the current was significantly decreased. 4. Initial galvanic current was 12.6 ${\mu}A$ in spherical amalgam (low copper amalgam) and 13.8 ${\mu}A$ in Tytin amalgam and the amount of change was lower in sperical amalgam and Tytin amalgam than that in lathe cut amalgam and Dispersalloy amalgam. 5. Painting ammoniated silver-nitrate or Copalite on the surface of amalgam resotration decreased initial galvanic current and ammoniated silver-nitrate is more effective in decreasing galvanic current than Copalite. 6. Galvanic current by contact between amalgam restoration and gold restoration increased abruptly and dropped rapidly becoming almost.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.469-481
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• 1993

The purpose of this study was to achieve the reduction of the galvanic current between the dental amalgam alloy and gold alloy. In order to measure the galvanic current between these two metals a prep in the size of $4{\times}13mm$ which was filled with amalgam and another prep of $4{\times}2mm$ was filled with gold alloy was made in the acrylic resin. These two preps were then connected to a 2mm diameter copper wire. Using an ammeter to measure the galvanic current, six different kinds of amalgam and gold alloy were immersed in saline solution with approximately 10mm distance between the two alloys. Chemical agents that are thought to reduce the galvanic current such as hydrazine. silver nitrate, potassium chromate, and bonding agents such as Scotch bond 2(3M) and All bond 2(Bisco) were applied to the alloy surface. Cathodic inhibitor such as hydrazine was applied to gold alloy where as anodic inhibitor such as silver nitrate and potassium chromate were applied to amalgam. Both bonding agents, Scotch bond 2(3M) and All bond 2 (Bisco), were applied to amalgam. The following results were obtained when the currency on the coated alloy surface was compared to the uncoated surface. 1. The galvanic currency went down as the time elapsed and after 30 minutes no change was detected. 2. Initial currency was higher in low copper amalgam compared to high copper amalgam. Intitial currency was the highest in low copper lathe-cut amalgam. 3. Group of gold coated with hydrazine had the most reduction in galvanic currency. 4. Group of amalgam coated with silver nitrate or potassium chromate also showed significant reduction in galvanic currency. 5. The bonding agents also helped reduce galvanic currency. 6. Of all the agents used to reduce galvanic currency, silver nitrate showed the best result.

• Journal of Advanced Marine Engineering and Technology
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• 제25권2호
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• pp.344-350
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• 2001

This paper was studied on the characteristics of galvanic corrosion and its protection on heat exchanger tube plate in the sea water. In this paper, behavior of pitting corrosion of Ni-al bronze connected with Ti tube was measured af flow velocity of 0 m/s and 2.4 m/s. To protect galvanic corrosion, the protection characteristics of Ni-Al bronze connected with Ti tube by Zn-base alloys galvanic anode and hexagonal nylon insert was investigated. Main results obtained asre al follows: 1) The galvanic corrosion of Ni-Al bronze connected with Ti-tube is more active than single Ni-al bronze. 2) As the circuit resistance increase under the cathodic protection employing Zn-base alloys galvanic anode, Ni-al bronze connected with Ti tube is cathodically unpolarized. 3) The corrosion of Ni-Al bronze connected with Ti tube by nylon insert controls approximately 73% than not nylon insert.

• Journal of Advanced Marine Engineering and Technology
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• 제25권2호
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• pp.345-345
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• 2001

This paper was studied on the characteristics of galvanic corrosion and its protection on heat exchanger tube plate in the sea water. In this paper, behavior of pitting corrosion of Ni-al bronze connected with Ti tube was measured af flow velocity of 0 m/s and 2.4 m/s. To protect galvanic corrosion, the protection characteristics of Ni-Al bronze connected with Ti tube by Zn-base alloys galvanic anode and hexagonal nylon insert was investigated. Main results obtained asre al follows: 1) The galvanic corrosion of Ni-Al bronze connected with Ti-tube is more active than single Ni-al bronze. 2) As the circuit resistance increase under the cathodic protection employing Zn-base alloys galvanic anode, Ni-al bronze connected with Ti tube is cathodically unpolarized. 3) The corrosion of Ni-Al bronze connected with Ti tube by nylon insert controls approximately 73% than not nylon insert.

• Corrosion Science and Technology
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• 제8권1호
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• pp.27-39
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• 2009

Non metallic composite materials, for example, GECM(graphite epoxy composite material) show high specific strength because of low density. These kinds of non metallic composite materials improved the structural effectiveness and operation economics. However, if these materials contacted several metals, corrosion can be arisen since non metallic composite materials have electrical conductivity. This paper dealt with galvanic corrosion between graphite epoxy composite material and several metals. Base on the electrochemical galvanic corrosion test between GECM and metals, corrosion current of carbon steel and aluminium increased with time but corrosion current of stainless steels and titanium decreased and galvanic potential increased. This behavior shows the galvanic corrosion depends upon the presence of passive film. Also, galvanic effect of GECM coupled with ferrous alloys and non-ferrous alloys was lower than that of 100% graphite, which is attributed to lower exposed area of graphite fiber in the GECM than apparent area of the GECM specimen used for the calculation of galvanic current in this work.

• 한국정보통신학회논문지
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• 제26권9호
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• pp.1347-1356
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• 2022

본 연구에서는 소자의 크기에 따른 코발트-저마늄 박막 기반의 galvanic cell의 특성을 조사하고, 이를 물 접촉 감지에 활용하기 위한 아두이노 기반 사물인터넷 센서 네트워크에의 적용을 제시한다. 본 연구에서 제안하는 코발트 저마늄 박막 기반 galvanic cell은 기존의 압전, 열전 에너지 하베스팅 소자와 다르게, 소자의 손상을 줄 수 있는 기계적인 변형이나 온도 구배를 필요로 하지 않는다는 점에서, 자가발전 센서 네트워크를 구축하는데 있어 더욱 적합한 에너지 하베스팅 소자로 적합하다. 본 연구는 스퍼터링 방식으로 증착된 코발트-저마늄 박막 기반의 galvanic cell을 센서로 활용함으로써 향후 자가발전 센서 네트워크의 실현 가능성에 대해 논의함으로써 향후 연구, 개발될 발전된 형태의 센서 네트워크 구축에 기여할 것으로 기대된다.

• 수산해양교육연구
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• 제15권1호
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• pp.115-122
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• 2003

Generally, material for radiator of automobile is composed of Al-alloy, but part of radiator material is still composed of Cu. Specially, Al-alloy replaces Cu and Cu-alloy as cooling and heating system material for light weight. Therefore, galvanic electronic cell is formed between Al-alloy and Cu for automobile radiator material, and Al-alloy corrosion is accelerated. So, in this study, galvanic corrosion test of Al-alloy coupling with Cu was carried out in distilled water, tap water, polluted environment and non-freezing solution. And thus corrosion potential and galvanic currrent density of Al-alloy coupling with Cu is investigated.

• 대한임상전기생리학회지
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• 제2권3호
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• pp.65-73
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• 2004

In experimental method, this study was that galvanic vestibular stimulation in vestibular system influenced the excitability of spinal neuron through. H-reflex was measured by galvanic vestibular stimulation of binaural(right-negative pole and left-positive pole) at left head turning and prone position in sixteen normal subjects in their twenties age were selected. The summary of the comparison results were obtained below. 1. In the change of H reflex according to galvanic vestibular stimulation(GVS), Hmax amplitude(p<.05) increased significantly after stimulation. 2. In the change of H reflex according to galvanic vestibular stimulation(GVS), Hmax/Mmax ratio(p<.05) increased significantly after stimulation. In the conclusion, galvanic vestibular stimulation influenced the excitability of vestibulospinal tract and spinal neuron.