FprEN ISO 10993-15
(Main)Biological evaluation of medical devices - Part 15: Identification and quantification of degradation products from metals and alloys (ISO/FDIS 10993-15:2019)
Biological evaluation of medical devices - Part 15: Identification and quantification of degradation products from metals and alloys (ISO/FDIS 10993-15:2019)
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Biologische Beurteilung von Medizinprodukten - Teil 15: Qualitativer und quantitativer Nachweis von Abbauprodukten aus Metallen und Legierungen (ISO/FDIS 10993-15:2019)
Dieses Dokument legt allgemeine Anforderungen zur Konzeption von Prüfungen für den qualitativen und quantitativen Nachweis von Abbauprodukten von fertigen Medizinprodukten aus Metall oder entsprechenden Werkstoffproben im Endzustand fest, die zur klinischen Anwendung bereit sind.
Dieses Dokument ist nur auf solche Abbauprodukte anwendbar, die durch eine chemische Veränderung des fertigen Metallproduktes in einer In vitro Prüfung erzeugt werden. Aufgrund der Natur dieser In vitro Prüfungen entsprechen die Prüfergebnisse in etwa dem In vivo Verhalten des Implantats oder des Werkstoffs. Die beschriebenen chemischen Verfahren sind ein Mittel, um Abbauprodukte für weitere Bewertungen zu erzeugen.
Dieses Dokument ist anwendbar sowohl auf Materialien, die dafür vorgesehen sind, vom Körper abgebaut zu werden, als auch auf solche, bei denen das nicht vorgesehen ist.
Dieses Dokument gilt nicht für eine Beurteilung des Abbaus durch rein mechanische Prozesse. Methoden zur Generierung dieser Art von Abbauprodukten sind, falls vorhanden, in den spezifischen Produktnormen beschrieben.
ANMERKUNG Rein mechanischer Abbau verursacht meist partikelförmiges Material. Obwohl dieses aus dem Anwendungsbereich dieses Dokuments ausgeschlossen ist, können solche Abbauprodukte eine biologische Reaktion hervorrufen und einer biologischen Beurteilung, wie in anderen Teilen der ISO 10993 beschrieben, unterzogen werden.
In Anbetracht des breiten Spektrums an metallischen Werkstoffen, die für Medizinprodukte verwendet werden, werden keine spezifischen analytischen Verfahren zum quantitativen Nachweis der Abbauprodukte festgelegt. Der Nachweis von Spurenelementen (< 10−6 w/w), die in bestimmten Metallen oder Legierungen vorhanden sind, wird in diesem Dokument nicht beschrieben. Ebenso legt dieses Dokument keine spezifischen Anforderungen für akzeptierbare Toleranzwerte von Abbauprodukten fest.
Dieses Dokument beschreibt nicht die biologische Aktivität der Abbauprodukte. (Hierzu wird auf die anwendbaren Abschnitte von ISO 10993 1 und ISO 10993 17 verwiesen.)
Évaluation biologique des dispositifs médicaux - Partie 15: Identification et quantification des produits de dégradation issus des métaux et alliages (ISO/FDIS 10993-15:2019)
Le présent document spécifie les exigences générales pour la conception des essais d'identification et de quantification des produits de dégradation issus de dispositifs médicaux métalliques finaux ou d'échantillons des matériaux correspondants prêts pour une utilisation clinique.
Le présent document ne s'applique qu'aux produits de dégradation créés par une modification chimique du dispositif métallique final et au moyen d'un essai de dégradation in vitro. En raison de la nature des essais in vitro, les résultats d'essai donnent une approximation du comportement in vivo de l'implant ou du matériau. En raison du caractère accéléré de ces essais, la méthodologie chimique décrite est un moyen de générer des produits de dégradation en vue d'analyses ultérieures.
Le présent document s'applique aux matériaux conçus pour se dégrader dans le corps, ainsi qu'aux matériaux qui ne sont pas conçus pour se dégrader.
Le présent document n'est pas applicable à l'évaluation de la dégradation qui se produit uniquement suite à des processus mécaniques; les méthodologies de génération de ce type de produit de dégradation sont décrites, le cas échéant, dans les normes des produits considérés.
NOTE La dégradation purement mécanique donne principalement de la matière sous forme de particules. Bien qu'ils n'entrent pas dans le domaine d'application du présent document, de tels produits de dégradation peuvent entraîner une réponse biologique et peuvent subir une évaluation biologique telle que celle décrite dans les autres parties de l'ISO 10993.
En raison de la grande variété des matériaux métalliques utilisés dans la fabrication des dispositifs médicaux, la présente partie de l'ISO 10993 n'indique aucune technique d'analyse spécifique pour la quantification des produits de dégradation. Le présent document ne traite pas de l'identification d'éléments à l'état de trace (< 10−6 w/w) contenus dans le métal ou l'alliage analysé. Il ne fournit aucune exigence spécifique relative aux niveaux admissibles de produits de dégradation.
Le présent document ne couvre pas l'activité biologique des produits de dégradation (pour cela, voir les articles correspondants de l'ISO 10993-1 et de l'ISO 10993-17).
Biološko ovrednotenje medicinskih pripomočkov - 15. del: Identifikacija in ugotavljanje količine razgradnih produktov iz kovin in zlitin (ISO/DIS 10993-15:2018)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN ISO 10993-15:2018
01-junij-2018
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Biological evaluation of medical devices - Part 15: Identification and quantification of
degradation products from metals and alloys (ISO/DIS 10993-15:2018)Biologische Beurteilung von Medizinprodukten - Teil 15: Qualitativer und quantitativer
Nachweis von Abbauprodukten aus Metallen und Legierungen (ISO/DIS 10993-15:2018)Évaluation biologique des dispositifs médicaux - Partie 15: Identification et quantification
des produits de dégradation issus des métaux et alliages (ISO/DIS 10993-15:2018)Ta slovenski standard je istoveten z: prEN ISO 10993-15
ICS:
11.100.20 %LRORãNRRYUHGQRWHQMH Biological evaluation of
PHGLFLQVNLKSULSRPRþNRY medical devices
oSIST prEN ISO 10993-15:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN ISO 10993-15:2018
DRAFT INTERNATIONAL STANDARD
ISO/DIS 10993-15
ISO/TC 194 Secretariat: DIN
Voting begins on: Voting terminates on:
2018-04-24 2018-07-17
Biological evaluation of medical devices —
Part 15:
Identification and quantification of degradation products
from metals and alloys
Évaluation biologique des dispositifs médicaux —
Partie 15: Identification et quantification des produits de dégradation issus des métaux et alliages
ICS: 11.100.20THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 10993-15:2018(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2018
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oSIST prEN ISO 10993-15:2018
ISO/DIS 10993-15:2018(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.ISO copyright office
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Email: copyright@iso.org
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Published in Switzerland
ii © ISO 2018 – All rights reserved
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oSIST prEN ISO 10993-15:2018
ISO/DIS 10993-15:2018(E)
Contents Page
Foreword ........................................................................................................................................................................................................................................iv
Introduction ..................................................................................................................................................................................................................................v
1 Scope ................................................................................................................................................................................................................................. 1
2 Normative references ...................................................................................................................................................................................... 1
3 Terms and definitions ..................................................................................................................................................................................... 2
4 Degradation test methods .......................................................................................................................................................................... 2
4.1 General ........................................................................................................................................................................................................... 2
4.2 Prerequisites ............................................................................................................................................................................................. 3
5 Reagent and sample preparation ........................................................................................................................................................ 3
5.1 Sample documentation .................................................................................................................................................................... 3
5.2 Test solution (electrolyte) ............................................................................................................................................................. 3
5.3 Preparation of test samples ......................................................................................................................................................... 4
5.3.1 Test samples......................................................................................................................................................................... 4
5.3.2 Sampling.................................................................................................................................................................................. 4
5.3.3 Sample shape ...................................................................................................................................................................... 4
5.3.4 Sample surface condition ......................................................................................................................................... 4
6 Electrochemical tests ....................................................................................................................................................................................... 4
6.1 Apparatus .................................................................................................................................................................................................... 4
6.2 Sample preparation ............................................................................................................................................................................ 5
6.3 Test conditions ........................................................................................................................................................................................ 5
6.4 Potentiodynamic measurements ......... .................................................................................................................................... 5
6.5 Potentiostatic measurements .................................................................................................................................................... 7
7 Immersion test ....................................................................................................................................................................................................... 7
7.1 Apparatus .................................................................................................................................................................................................... 7
7.2 Sample preparation ............................................................................................................................................................................ 8
7.3 Immersion test procedure ............................................................................................................................................................ 8
8 Analysis .......................................................................................................................................................................................................................... 9
9 Test report ................................................................................................................................................................................................................... 9
Annex A (normative) Electrolytes for the electrochemical tests ..........................................................................................10
Annex B (informative) Schematic diagram of the electrochemical measuring circuit ..................................11
Annex C (informative) Schematic drawing of an electrolytic cell ........................................................................................12
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 93/42/EEC [OJ L 169] aimed to be covered ....................................................14
Annex ZB (informative) Relationship between this European Standard and the essential
requirements of Directive 90/385/EEC [OJ L 189] aimed to be covered ................................................15
Annex ZC (informative) Relationship between this European Standard and the general
health and safety requirements of Regulation (EU) 2017/745 on medical devicesaimed to be covered .......................................................................................................................................................................................17
Bibliography .............................................................................................................................................................................................................................18
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ISO/DIS 10993-15:2018(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the
Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 194, Biological and clinical evaluation of
medical devices.This second edition cancels and replaces the first edition (ISO 10993-15:2000), which has been
technically revised.The main changes compared to the previous edition are as follows:
a) document now considers materials designed to degrade in the body as well as materials that are
not intended to degrade;b) information on test methods amended to consider nanomaterials and relevant material specific
standards;c) test solution (electrolyte) more specified;
d) sample shape more specified;
e) immersion test procedure expanded;
f) Annex C changed to normative and now Annex A.
A list of all parts in the ISO 10993- series can be found on the ISO website.
iv © ISO 2018 – All rights reserved
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Introduction
One of the potential health hazards resulting from medical devices may be due to the interactions
of their electrochemically induced degradation products with the biological system. Therefore, the
evaluation of potential degradation products from metallic materials by methods suitable for testing
the electrochemical behavior of these materials is a necessary step in the biological performance
testing of materials.The body environment typically contains cations of sodium, potassium, calcium, and magnesium, and
anions of chloride, bicarbonate, phosphate, and organic acids generally in concentrations between 2 x 10
–3 mol and 150 x 10 –3 mol. A range of organic molecules such as proteins, enzymes, and lipoproteins is
also present, but their concentrations may vary to a great extent. Earlier studies assumed that organic
molecules did not exert a significant influence on the degradation of metallic implants, but newer
investigations indicate that implant–protein interactions should be taken into account. Depending on
a particular product or application, altering the pH of the testing environment may also need to be
considered.In such biological environments, metallic materials may undergo a certain degradation, and the
different degradation products may interact with the biological system in different ways. Therefore,
the identification and quantification of these degradation products is an important step in evaluating
the biological performance of medical devices.© ISO 2018 – All rights reserved v
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oSIST prEN ISO 10993-15:2018
DRAFT INTERNATIONAL STANDARD ISO/DIS 10993-15:2018(E)
Biological evaluation of medical devices —
Part 15:
Identification and quantification of degradation products
from metals and alloys
1 Scope
This document provides guidance on general requirements for the design of tests for identifying and
quantifying degradation products from final metallic medical devices or corresponding material
samples finished as ready for clinical use.This document is applicable only to those degradation products generated by chemical alteration of the
final metallic device in an in vitro accelerated degradation test. Because of the accelerated nature of
these tests, the test results may not reflect the implant or material behavior in the body. The described
chemical methodologies are a means to generate degradation products for further assessments.
This document considers both materials designed to degrade in the body as well as materials that are
not intended to degrade.This document is not applicable to degradation products induced by applied mechanical stress.
Mechanically induced degradation, such as wear, can be covered in the appropriate product-specific
standard. Where product-group standards provide applicable product-specific methodologies for the
identification and quantification of degradation products, those standards should be considered.
Because of the wide range of metallic materials used in medical devices, no specific analytical
techniques are identified for quantifying the degradation products. The identification of trace elements
(< 10 w/w) contained in the specific metal or alloy is not addressed in this part of ISO 10993, nor are
specific requirements for acceptable levels of degradation products provided in this part of ISO 10993.
This document does not address the biological activity of the degradation products; see instead the
applicable clauses of ISO 10993-1 and ISO 10993-17.2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3585, Borosilicate glass 3.3 — PropertiesISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 8044, Corrosion of metals and alloys — Basic terms and definitions
ISO 10993-1, Biological evaluation of medical devices — Part 1: Evaluation and testing within a risk
management processISO 10993-9, Biological evaluation of medical devices — Part 9: Framework for identification and
quantification of potential degradation productsISO 10993-12, Biological evaluation of medical devices — Part 12: Sample preparation and reference
materials© ISO 2018 – All rights reserved 1
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ISO 10993-13, Biological evaluation of medical devices — Part 13: Identification and quantification of
degradation products from polymeric medical devicesISO 10993-14, Biological evaluation of medical devices — Part 14: Identification and quantification of
degradation products from ceramicsISO 10993-16, Biological evaluation of medical devices — Part 16: Toxicokinetic study design for
degradation products and leachables3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8044, ISO 10993-1,
ISO 10993-9, ISO 10993-12 and the following apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses:
IEC Electropedia: available at http:// www .electropedia .org/ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1
alloy
material composed of a metallic element with one or more addition(s) of other metallic and/or non-
metallic elements3.2
electrolyte
solution containing ions with the capacity to conduct electric current
3.3
open-circuit potential
potential of an electrode measured with respect to a reference electrode or another electrode when no
current flows to or from it3.4
passive limit potential
electrode potential of the positive limit of the passive range
Note 1 to entry: See Figure 1.
3.5
breakdown potential
critical electrode potential above which localized or transpassive corrosion is found to occur
Note 1 to entry: See Figure 1.4 Degradation test methods
4.1 General
To identify and quantify degradation products from metals and alloys in medical devices, a combination
of two procedures is described. The choice of test procedure shall be justified according to the function
of the medical device.The first procedure described is a combination of a potentiodynamic test and a potentiostatic test. The
second procedure described is an immersion test.2 © ISO 2018 – All rights reserved
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The potentiodynamic test is used to determine the general electrochemical behavior of the material
under consideration and to determine certain specific points (E and E ) on the potential/current
a pdensity curve.
The immersion test is used to chemically degrade the test material to generate degradation products to
be analyzed.If there is the possibility of the loss of a coating from a metallic substrate due to degradation, the
potential degradation products from the substrate material shall be considered, as well as the
coating itself. In addition, if a metallic substrate coated with a non-metallic material is to be tested,
the requirements of ISO 10993-13 and/or ISO 10993-14 shall be considered in order to determine the
potential degradation products of the coating.The identified and quantified degradation products form the basis for evaluation of biological response
and, if appropriate, toxicokinetic studies in accordance with ISO 10993-16.For those medical devices composed of or containing nanoscale materials, and for those instances where
metallic degradation products are within the nanoscale size range (approximately 1 nm to 100 nm), the
user is referred to ISO 10993-22 when creating their risk assessment documents.If the medical device is made using a metal or metal alloy designed to be absorbed by the body, the
user is directed to relevant material specific standards (see bibliography) for methods and specific
considerations (e.g. electrolyte, atmosphere, etc.) appropriate for this class of materials.
4.2 PrerequisitesThe rates of electrochemical degradation reactions are sensitive to small variations in test conditions,
instrumentation, sample conditions, and preparation. Therefore, electrochemical degradation testing
shall be carried out in an appropriately equipped laboratory by experienced and qualified personnel.
This includes proper maintenance and calibration of the test equipment. The methods and operating
conditions of the equipment shall also be validated.Fulfillment of electrochemical test conditions for stability, warm-up time, etc., can be demonstrated by
[1]conformance to.
5 Reagent and sample preparation
5.1 Sample documentation
The general composition of the material(s) under test shall be documented.
5.2 Test solution (electrolyte)
The test solution (electrolyte) to be used shall be appropriate for the intended use of the medical device.
All chemicals shall be of analytical grade and dissolved in water of grade 2 in accordance with ISO 3696.
The first choice for the electrolyte shall be an aqueous solution of 0,9 % sodium chloride.
Dependent on the composition and corrosion mechanism of the metal or alloy being tested, other
electrolytes may be used, such as artificial saliva or artificial plasma. Examples of electrolyte
compositions are given in Annex A, but other more material and physiologically relevant electrolyte
solutions and test conditions may be utilized. Possible effect of implant–protein interactions should be
taken into account.NOTE Formulations for artificial sweat, gastrointestinal fluids, and lung fluids have been used [see
Bibliography].In the test report, the choice of electrolyte shall be justified. If other than an aqueous solution of 0,9 %
sodium chloride is used, the pH of the electrolyte shall be specified.© ISO 2018 – All rights reserved 3
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5.3 Preparation of test samples
5.3.1 Test samples
The sensitivity of chemical degradation testing is related to variation in material composition, to
material processing, and to surface-finishing procedures. The sampling procedure, sample shape,
and surface preparation are critical. In addition, confined spaces can result in crevice corrosion and
defects in coatings can cause pit corrosion, which shall be taken into consideration. The samples shall
be representative of the final devices.5.3.2 Sampling
For each chemical test, at least two test samples shall be prepared as specified in ISO 10993-12. If
substantial deviations in the test results are found, the reasons for the deviation shall be determined,
and more samples shall be tested.If the metallic sample has anisotropic properties due to manufacturing conditions, tests involving
single-surface exposure should include samples cut parallel to both the transverse and longitudinal
manufacturing directions.5.3.3 Sample shape
Standard samples, either circular- or rectangular-section bars or flat coupons, or one single free
surface, may be used for degradation testing if they are prepared in a manner comparable to the final
medical device. Samples of actual device components may be of any shape and condition; however, the
testing shall be carried out under well-controlled conditions which shall be reported.
The surface area of the sample exposed to the electrolyte shall be determined to +/- 10% of the total
geometrical area to assure an accurate and repeatable determination of the degradation rates.
If representative samples are used, consideration shall be made regarding whether the differences
between the representative sample and the final medical device or component could affect the results
of the test. Testing of representative samples instead of the final medical device shall be supported by a
description of any differences between the representative sample and the final device. The report shall
contain a detailed rationale for why each difference is not expected to alter the biocompatibility of the
final device.5.3.4 Sample surface condition
Since the surface condition of a material may affect its electrochemical behavior, the surface condition of
the test sample shall be identical to the final medical device and shall be described in the test report. For
comparing test results of different materials, the surface condition of the test samples shall be the same.
6 Electrochemical tests6.1 Apparatus
Test cells of borosilicate glass, in appropriate sizes, in accordance with ISO 3585, with a means of
controlling the bath temperature within ± 1 °C.-9 –1
Scanning potentiostat with a potential range ± 2 V and a current output range from 10 A to 10 A.
Potential-measuring instrument with a high input impedance (>10 Ω) and a sensitivity and
accuracy to detect a change of 1 mV over a potential range between ± 2 V.Current-measuring instrument capable of measuring a current to ± 1 % of the absolute value over a
-9 –1current range between 10 A and 10 A.
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Working electrode (test sample).
Counter-electrode(s) such as platinum (grid, plate, or wire) or vitreous carbon with an area at least 10
times that of the working electrode.Reference electrode.
pH-meter with a sensitivity of ± 0,1.
A schematic diagram of the electrochemical measurement circuit which may be used as a system with
variable potential is given in Annex B.A schematic drawing of an electrolytic cell is given in Annex C.
6.2 Sample preparation
Mount the test sample in a watertight electrode holder so that only the test surface is in contact with
the electrolyte. Take care to avoid the creation of conditions where crevice corrosion can occur due to
the formation of a crevice between the mounting and the sample. Before testing, clean the specimen
ultrasonically for 10 min to 15 min in ethanol, carefully rinse with water of grade 2 in accordance with
ISO 3696, and immediately transfer into the test cell.6.3 Test conditions
Fill the test cell with the test solution (electrolyte). If the electrochemical behavior is temperature
sensitive in the range of 10 °C to 50 °C, maintain the electrolyte cell at (37 ± 1) °C. Reduce the oxygen level
3 –1in the electrolyte by bubbling oxygen-free nitrogen or argon at a rate of approximately 100 cm ▪min
for not less than 30 min prior to the start of the test. The electrolyte shall be agitated either by the
bubbling gas or mechanical means to avoid concentration gradients. If gas agitation is used, take care
not to have any gas bubbles adhering to the active test surface.Magnetic stirrers often interfere with electrochemical test cells. If they are used, their effect on the test
cell shall be determined as part of the validation of test equipment (see 4.2).6.4 Potentiodynamic measurements
Measure the open-circuit potential not less than 2 h after the immersion of the working electrode. This
potential shall be the starting potential for potentiodynamic measurements. The sweep rate shall be
1,0 mV▪s , except in tests where the sweep rate has little effect, where the test may be accelerated by
increasing the sweep rate to 10 mV▪s . Record the potential/current density curve up to a maximum
of 2 000 mV or a maximum current density of 1,0 mA▪cm , whichever comes first, to evaluate the
transpassive range of the sample (see Figure 1). To ensure consistency, reverse the scan and continue
back at least to the open-circuit potential. Then repeat the test back to 2 000 mV or 1,0 mA▪cm . If
the curves are not reproducible, then continue cycling 5 to 10 times. If consistent potential/current
density curves are not achieved after 5 to 10 cycles, investigate possible causes such as test set- up,
electrode function, innate material properties, etc. The log current density/potential curves should also
be recorded (see Figure 2). Record the breakdown potential (E ) from the last cycle taken (see Figure 1).
Noble metals may b...
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