Semiconducting properties of thermally grown oxide films on AISI 304 stainless steel

Hakiki, N. E.; Montemor, M.F.; Ferreira, M.G.S.; Belo, M. Da Cunha

doi:10.1016/s0010-938x(99)00082-7

Cited by 206 publications

(88 citation statements)

References 23 publications

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“…The electrode tip (needle) is made of stainless steel AISI 304 which has a thin oxide film that circumfuses the needle surface. In general, oxide films can be passively or thermally grown; they are composed of two layers: outer iron oxide layer and inner mixed iron-chromium oxide layer [7]. According to the same study the film thickness varies from 8 nm at 50 • C to 30 nm at 450 • C, mainly occurring in outer iron oxide layer.…”

Section: Solder Junction Structurementioning

confidence: 95%

Modelling and detection of failure in medical electrodes

2015

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In this paper we have studied the failures in medical electrodes such as electroencephalogram electrodes (EEG) being used for collecting brain signals. As those electrodes have to guarantee high level of reliability it is important to explore and predict the possible occurrence of failures in there structure. The electrode tip (needle) made of stainless steel is covered with thin oxide film acting as a dielectric and determing the total electrode resistance. In fact, studying the fluctuations of that resistance gives the insight into defects of the whole structure. The electrical properties of the oxide layer are characterized by charge hopping mechanism and the total resistance could be modeled by implementing random resistance network (RRN) methodology.The applied computational algorithm is based on Monte Carlo simulation procedure with direct and iteration methods. The obtained simulation results show non-gaussian Bramwell-Holdsworth-Pinton (BHP) distribution of the total resistance fluctuations, and they verified by the experiments. Key words: Cold solder, oxide layer, failure detection, biased percolation, RRN simulationModeliranje i detekcija kvara u medicinskim elektrodama. U ovom je radu razvijen model za simulaciju predviđanja defekata u posebnim elektrodama koje se koriste pri mjerenju i prikupljanju signala mozga. Ključni dio elektrode je njenčelični vrh prekriven tankim oksidnim slojem koji ujedno djeluje kao dielektrik. Upravo fluktuacije vrijednosti otpora dielektrika odnosno njihovo rasipanje od normalne do BHP raspodjele, korištene su kao osnova predloženog modela. Pritom je primjenjena metodologija mreže nasumičnih otpora (RRN), algoritam temeljen na Monte-Carlo simulacijama kao i teorija usmjerene perkolacije. Definiran je i poseban parametar kao indeks intervala valjanosti za svaku elektrodu. Simulacije su potvrđene mjerenjem u laboratorijskim uvjetima na komercijalnim EEG elektrodama.

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Section: Solder Junction Structurementioning

confidence: 95%

Modelling and detection of failure in medical electrodes

2015

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“…When the pitting potential is reached, the electric field strength in the thinner parts of the film is so high that chloride ions can penetrate the film, starting localized dissolution of the oxide film. Thus, once a pit has formed, it will continue to grow autocatalytic [7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Characterization of an Optical Fiber Laser- Treated Biomaterial

Pieretti¹,

Corrêa²,

Pillis³

et al. 2018

Biomaterials - Physics and Chemistry - New Edition

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The implant manufacturing process includes texturization to enhance its adhesion and marking the final products for their identification, long-term quality control and traceability. Marking is carried out after cleaning and prior to sterilization. These marks eventually can concentrate stress leading to premature failure. The marked areas are defective regions that affect the passive film formed on the metallic biomaterials used for implants favoring the onset of various corrosion types, such as pitting, crevice or fatigue. This study aims to evaluate the effect of a Yb optical fiber laser marking processes used for metallic implants on the localized corrosion resistance of the austenitic stainless steel ISO 5832-1. This is one of the most used materials for manufacturing implants. The electrochemical behavior of the marked areas obtained by this method was evaluated in a phosphate-buffered saline (PBS) solution with pH of 7.4 and the results were compared with unmarked samples. All tested surfaces were prepared according to the recommendations for the use in surgery. For localized corrosion resistance evaluation, electrochemical tests such as monitoring the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and cyclic potentiodynamic polarization measurements were performed. The results showed that the laser marks affect the protector characteristics of the biomaterial's passive film. Lower pitting resistance was associated to the laser marked areas.

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“…Vários artigos [15][16][17][18][19][20] foram publicados nos últimos anos, onde o comportamento semicondutor de filmes passivos em aços inoxidáveis fora investigado, relacionando suas propriedades eletrônicas com a resistência à corrosão.…”

Section: Propriedades Eletrônicas Do Filme Passivo Em Aços Inoxidáveisunclassified

“…O potencial de banda plana, onde não existe excesso de cargas em um semicondutor, pode ser obtido, no gráfico, pela extrapolação de 1/C² para zero. A concentração de dopantes N q é obtida pelas inclinações das curvas [15][16][17][18][19][20].…”

Section: Propriedades Eletrônicas Do Filme Passivo Em Aços Inoxidáveisunclassified

“…A região de depleção é caracterizada por sua deficiência de elétrons e ocorre em potenciais positivos a partir do potencial de banda plana (E bp ) para um semicondutor tipo-n e em potenciais negativos a partir de (E bp ) para um semicondutor tipo-p. A região de acumulação, caracterizada por um excesso de elétrons, ocorre em potenciais mais negativos a partir de (E bp ) para semicondutores tipo-n e mais positivos a partir de (E bp ) para semicondutores do tipo-p. As representações dos gráficos de Mott-Schottky sempre se dão nas formas das regiões de depleção [15][16][17][18][19][20].…”

Section: Propriedades Eletrônicas Do Filme Passivo Em Aços Inoxidáveisunclassified

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Efeito da marcação na resistência à corrosão de implantes ortopédicos produzidos em aço inoxidável ABNT NBR ISO 5832-1

Pieretti¹

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Semiconducting properties of thermally grown oxide films on AISI 304 stainless steel

Cited by 206 publications

References 23 publications

Modelling and detection of failure in medical electrodes

Modelling and detection of failure in medical electrodes

Electrochemical Characterization of an Optical Fiber Laser- Treated Biomaterial

Efeito da marcação na resistência à corrosão de implantes ortopédicos produzidos em aço inoxidável ABNT NBR ISO 5832-1

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