SIST EN ISO 14916:2017
(Main)Thermal spraying - Determination of tensile adhesive strength (ISO 14916:2017)
Thermal spraying - Determination of tensile adhesive strength (ISO 14916:2017)
The tensile adhesive strength is the strength obtained in the tension test. The test is used to evaluate the effects of parent metal and spray deposit material, preparation of the surface of the workpiece, and the spraying conditions on the bond and adhesive strength of thermally sprayed coatings, and doe eoutine supervision of the spray works during fabrication. The document contains specimens of various diameters and of different shapes.
Thermisches Spritzen - Ermittlung der Haftzugfestigkeit (ISO 14916:2017)
Dieses Dokument legt das Verfahren zur Ermittlung der Haftzugfestigkeit bei einem thermischen Spritzverfahren unter Zugbeanspruchung in senkrechter Richtung zur Oberfläche der Beschichtung mithilfe eines Zugversuches fest. Durch Anwendung dieses Verfahrens wird die Vergleich¬barkeit der Prüfergebnisse gewährleistet.
Mithilfe der Prüfung soll die Haftzugfestigkeit thermisch gespritzter Schichten und dem Werkstoff oder zwischen der Klebeschicht und der obersten Beschichtung und/oder die Bindefestigkeit der betreffenden Schicht des Beschichtungssystems ermittelt werden. In einigen Fällen, können thermisch gespritzte Beschichtungen mehr als zwei Schichten haben. Das in diesem Dokument beschriebene Verfahren ist auch anwendbar, um die Haftzugfestigkeit zwischen den Verbindungsstücken der verschiedenen Schichten in einem beschichteten System, welches aus mehr als zwei Schichten besteht, zu bestimmen.
Diese Prüfung ist ausreichend, um Beschichtungen miteinander zu vergleichen, die aus den gleichen oder ähnlichen Spritzmaterialien und thermischen Spritzprozessen hervorgegangen sind. Die Prüfung auf Haftzugfestigkeit soll keine definitiven Werte für die Berechnung der Dauerhaftigkeit von Beschichtungen unter Beanspruchung liefern.
Die Prüfung wird angewendet, um den Einfluss der Materialvorbereitung der zu beschichtenden Werkstück¬oberfläche, der Spritzbedingungen und der Prozessparameter auf die Haftzugfestigkeit der thermischen Spritzschichten zu beurteilen. Sie kann auch angewendet werden, um die Einheitlichkeit der Herstellung und der Spritz¬arbeiten zu überwachen.
ANMERKUNG Diese Zugprüfung eignet sich auch für sehr dünne Beschichtungen und kann zudem durch Ver¬wen-dung eines geeigneten Klebstoffs (Folienklebstoff eher als Flüssigklebstoff) die Infiltrierung auch bei Spritz¬be-schichtungen mit einer erforderlichen Porositätsstufe minimieren. Weitere Anweisungen können 6.5.3 entnommen wer¬den. Für die Bestimmung der Haftzugfestigkeit bei aufgeschmolzenen Spritzbeschichtungen aus selbstfließenden Legierungen ist diese Zugprüfung wegen der hohen Kräftewerte nicht geeignet.
Projection thermique - Mesure de l'adhérence par essais de traction (ISO 14916:2017)
ISO 14916:2017 spécifie le mode opératoire permettant de déterminer la résistance d'adhérence en traction de revêtements obtenus par projection thermique sous une charge de traction appliquée perpendiculairement à la surface du revêtement lors d'un essai de traction. L'utilisation de ce mode opératoire permet de comparer les résultats d'essai.
L'essai vise à déterminer la résistance d'adhérence en traction entre le revêtement obtenu par projection thermique et le matériau du substrat ou entre la couche de liaison et la couche de finition et/ou la cohésion du revêtement concerné d'un système de revêtement. Dans certains cas, les revêtements obtenus par projection thermique peuvent comporter plus de deux couches. La méthode spécifiée dans le présent document s'applique également pour déterminer la résistance d'adhérence en traction entre les interfaces des différentes couches d'un système de revêtement constitué de plus de deux couches.
Cet essai est suffisant pour comparer des revêtements obtenus à l'aide de matières premières et de procédés de projection thermique identiques ou similaires. La mesure de l'adhérence par essais de traction n'est pas destinée à fournir des valeurs absolues pour l'évaluation de la durabilité des revêtements dans des conditions d'exploitation.
L'essai est utilisé pour évaluer l'influence de la préparation du substrat, des conditions de projection et des paramètres du procédé sur la résistance d'adhérence en traction de revêtements obtenus par projection thermique. Il peut également être employé pour surveiller la constance de la fabrication et des procédés de projection.
NOTE Cet essai de traction peut également être appliqué à des revêtements très minces. De plus, l'infiltration d'adhésif dans les revêtements obtenus par projection thermique présentant un niveau de porosité prescrit peut être réduite en utilisant un adhésif approprié (en feuille plutôt que liquide). Voir 6.5.3 pour des instructions supplémentaires. Cet essai de traction n'est pas approprié à la mesure de la résistance d'adhérence de revêtements projetés et fondus déposés à l'aide d'alliages autofondants, en raison de leurs valeurs d'adhérence intrinsèques élevées.
Vroče brizganje - Ugotavljanje adhezijske natezne trdnosti (ISO 14916:2017)
Adhezijska natezna trdnost je trdnost, pridobljena pri nateznem preskusu. Preskus se uporablja za ocenjevanje učinkov glavne kovine in z brizganjem nanesenega materiala, priprave površine obdelovanca in pogojev brizganja na sprijemno in adhezijsko trdnost premazov, nanesenih z brizganjem, ter za rutinski nadzor brizgalnih del med izdelavo. Dokument vsebuje preskušance različnih premerov in različnih oblik.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 14916:2017
01-junij-2017
1DGRPHãþD
SIST EN 582:1999
9URþHEUL]JDQMH8JRWDYOMDQMHDGKH]LMVNHQDWH]QHWUGQRVWL ,62
Thermal spraying - Determination of tensile adhesive strength (ISO 14916:2017)
Thermisches Spritzen - Ermittlung der Haftzugfestigkeit (ISO 14916:2017)
Projection thermique - Mesure de l'adhérence par essais de traction (ISO 14916:2017)
Ta slovenski standard je istoveten z: EN ISO 14916:2017
ICS:
25.220.20 Površinska obdelava Surface treatment
SIST EN ISO 14916:2017 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 14916:2017
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SIST EN ISO 14916:2017
EN ISO 14916
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2017
EUROPÄISCHE NORM
ICS 25.220.20 Supersedes EN 582:1993
English Version
Thermal spraying - Determination of tensile adhesive
strength (ISO 14916:2017)
Projection thermique - Mesure de l'adhérence par Thermisches Spritzen - Ermittlung der
essais de traction (ISO 14916:2017) Haftzugfestigkeit (ISO 14916:2017)
This European Standard was approved by CEN on 8 March 2017.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14916:2017 E
worldwide for CEN national Members.
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SIST EN ISO 14916:2017
EN ISO 14916:2017 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 14916:2017
EN ISO 14916:2017 (E)
European foreword
This document (EN ISO 14916:2017) has been prepared by Technical Committee ISO/TC 107 "Metallic
and other inorganic coatings" in collaboration with Technical Committee CEN/TC 240 “Thermal
spraying and thermally sprayed coatings” the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2017, and conflicting national standards
shall be withdrawn at the latest by September 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN 582:1993.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 14916:2017 has been approved by CEN as EN ISO 14916:2017 without any modification.
3
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SIST EN ISO 14916:2017
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SIST EN ISO 14916:2017
INTERNATIONAL ISO
STANDARD 14916
Second edition
2017-03
Thermal spraying — Determination of
tensile adhesive strength
Projection thermique — Mesure de l’adhérence par essais de traction
Reference number
ISO 14916:2017(E)
©
ISO 2017
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, 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.
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Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles . 2
5 Equipment for testing and measuring and auxiliary equipment . 3
5.1 Test instruments . 3
5.2 Measurement instrument . 3
5.3 Specimen fixing device for bonding of the tensile adhesive specimen . 4
6 Specimens . 4
6.1 Shape of specimens . 4
6.2 Material of the specimen . 6
6.3 Preparing the substrate and loading blocks . 6
6.4 Preparing and spraying of the specimen . 8
6.5 Manufacture of the specimens for tensile testing . 9
6.5.1 Machining of the coated substrate block (or test disc) and preparation
for bonding. 9
6.5.2 Gluing the specimen . . 9
6.5.3 Bonding agent . 9
6.6 Reference specimen .10
6.7 Number of specimens to be tested .10
7 Applying the testing .10
8 Measurement readings and evaluation .11
9 Test report — Documentation .12
10 Possible sources of fault when preparing the specimens and on testing .13
Annex A (informative) Work instructions for gluing .14
Annex B (informative) Recommendations for further auxiliary equipment .17
Annex C (informative) Function areas on the tensile adhesive specimen and possibilities of
fracture locations according to ASTM C633-13 .21
Annex D (informative) Record for the applied tensile adhesive test according to this document .22
Bibliography .26
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SIST EN ISO 14916:2017
ISO 14916:2017(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 voluntary nature of standards, 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: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings.
This second edition cancels and replaces the first edition (ISO 14916:1999), which has been technically
revised.
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
Introduction
The determination of the tensile adhesive strength of a thermal spray coating can play an important
role in the quality control of production. Deviations from the normal and qualified procedure can be
recognized when preparing and spraying a component.
If the fracture occurs cohesively in the coating when applying the tensile adhesive strength test, the
coating’s strength in the direction normal to the surface is supplied. Influences of variations in spray
conditions can be identified via proper interpretation of tensile test results. Microscopic investigations
of the fractured surface can supply further information for judging the quality of the coating‘s structure.
A revision of the existing document had been required as a result of the identification of significant
influences on the test results caused by the tensile test bonding procedure and by the properties of the
adhesive itself. These findings were not adequately covered in the previous version of this document.
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SIST EN ISO 14916:2017
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SIST EN ISO 14916:2017
INTERNATIONAL STANDARD ISO 14916:2017(E)
Thermal spraying — Determination of tensile adhesive
strength
1 Scope
This document specifies the procedure to determine the tensile adhesive strength of thermally sprayed
coatings under tension in the direction normal to the surface of the coating by applying a tensile test.
By using this procedure, comparability of the test results is ensured.
The test is intended to determine the tensile adhesive strength between the thermally sprayed coating
and the substrate material or between the bond and top coat and/or of the cohesive strength of the
related coat of the coating system. In some cases, thermally sprayed coatings might have more than two
layers. The method specified in this document applies also to determine the tensile adhesive strength
between the interfaces of different layers in a coating system which consists of more than two layers.
This test is sufficient to compare coatings manufactured using same or similar feedstock materials and
thermal spray processes with each other. The tensile adhesive strength test is not intended to provide
absolute values for evaluation of the durability of coatings under operational use.
The test is used to assess the influence of substrate preparation, the spraying conditions and the process
parameter on the tensile adhesive strength of thermally sprayed coatings. It can also be employed in
order to monitor the consistency of the manufacturing and spraying processes.
NOTE This tensile test can also be applied to very thin coatings. Moreover, the infiltration of bonding
agent into the thermally sprayed coatings containing a required level of porosity can be minimized using an
appropriate bonding agent (foil rather than liquid). For further instructions, please refer to 6.5.3. This tensile
test is inappropriate for determining the adhesive strength of fused spray coatings deposited using self-fluxing
alloys due to their inherent high adhesion strength values.
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 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 14917, Thermal spraying — Terminology, classification
EN 13507, Thermal spraying — Pre-treatment of surfaces of metallic parts and components for thermal
spraying
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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 http:// www .iso .org/ obp
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
3.1
adhesive strength
R
H
tensile strength measured in the tension test, which is calculated from the quotient of the maximum
load F and the cross-section area of the fractured face
max
3.2
adhesive failure
fracture, which runs along the interface between coating and substrate
Note 1 to entry: The coating will be totally separated away from the substrate.
Note 2 to entry: The inter-particle bonding (cohesive strength) is higher than the adhesive strength of the coating.
3.3
cohesive failure
fracture, which takes place within the coating
Note 1 to entry: The inter-particle bonding (cohesive strength) is lower than the adhesion strength of the coating.
3.4
adhesive-cohesive failure
fracture, which is partially located in the interface of the coating to the substrate and partially within
the coating
3.5
internal adhesive strength
adhesive strength between the layers of a coating system, e.g. between a bond and top coat
3.6
test disc
test specimen formed like a disc coated on one side
Note 1 to entry: This is to be positioned and glued between two loading blocks when preparing the tensile test
specimen.
3.7
reference specimen
specimen for determination of the strength of bonding agent
Note 1 to entry: This consists of two uncoated loading blocks glued together using the same joining procedure as
for all other tested specimens.
4 Principles
The test methods listed in this document are recommended for quality control or characterization of
coatings and/or coating systems in order to improve thermal spray processes or to develop coatings
with increased adhesive and cohesive strength as well as with improved microstructure.
Thermally sprayed coatings exhibit as a thumb of rule — inherent to the characteristics of the process
— a porous microstructure. Due to the requirements of their targeted application areas, they may
contain a high level of porosity. Due to the possibility of infiltration of the coating by the bonding agent,
the porous character of a coating can be unfavourable. The development of incorrect types or quantities
of bonding agents can lead to significant changes in the coating properties so that the measurement
results can be invalid.
Furthermore, only loads normal to the coating surface, which are free of bending or torsion moments,
shall be applied during tensile loading. Therefore, adequate clamping and centring devices shall be used
during the entire manufacturing process of the test specimens and during the testing.
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
5 Equipment for testing and measuring and auxiliary equipment
5.1 Test instruments
A tensile testing machine according to ISO 7500-1, class 1, with a suitable clamping system shall be used,
which ensures clamping and loading of the specimens through the centre line following no bending and
torsion moments.
This can be achieved by a ball joint which is specified in this document (for details, see Figure 1) or
by a universal suspension [examples are according to ASTM C633-13 (see Figure B.4), EN 13144 and
ISO 13779-4). The M16 threaded drill hole shall bear and transfer the load to the specimen.].
Key
1 loading block
2 substrate block
3 ball joint
4 clamping part
Figure 1 — Arrangement for the tensile adhesion test with test specimen according to form A
5.2 Measurement instrument
Measurements can be carried out, when preparing the loading block and test specimens, using
measurement instruments in accordance with standard commercial practices. Recommendations and
examples for special gauges to measure the concentricity (see Figure B.2) and parallelism of specimens
with a 25,0 mm diameter are given in Annex B.
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
5.3 Specimen fixing device for bonding of the tensile adhesive specimen
A fixing apparatus, which keeps the angular and axial deviation of the blocks as low as possible, shall be
used in order to glue the loading block to the substrate block (or to the test disc). Furthermore, fixing
the apparatus shall ensure the application and maintaining of the required contact pressure over the
entire gluing process.
NOTE These objectives can be achieved by using a V-block fixture for centring. Using the fixture, the coaxial
alignment and a sufficient contact pressure can be maintained so that substrate and loading block (see Figure 2
for details) or two loading blocks and a test disc (see Figure 3 for details) can be joined together to form a tensile
adhesion specimen with required tolerances.
When applying the required contact pressure (generally low), it shall be ensured that neither bending
nor torsion moments affect the bonding joint.
Consideration should be given to defining the value of the required contact pressure. The contact
pressure shall be possibly constant over the entire temperature range during application and hardening
of the bonding agent. If the weight of the top loading block, with respect to the substrate block, is
inadequate to create the required load, then loading by means of a spring is recommended.
NOTE In case of a spring with an appropriate thread as an intermediate element, the displacement is
controlled, set by the number of screw revolutions, and is transferred into force. In this way, the contact pressure
can be set precisely by controlling the total number of screw revolutions. Formula (1) is valid for the calculation
of the required revolutions of the screw for setting-up of the necessary contact pressure.
2
pd××π
(1)
n =
4××cs
where
n number of revolutions of the screw;
p necessary contact pressure (Pa);
d diameter of the substrate block (m);
c spring constant (N/m);
s pitch length (m).
In order to avoid deviations of the spring’s force during heating and hardening of the bonding agent, the
spring shall be made out of a suitable steel. An adequate device is shown in Figure B.1.
6 Specimens
6.1 Shape of specimens
For the determination of the tensile strength when applying the tensile test, specimens of shape A or
B with diameters of 25,0 mm (respectively 25,4 mm) or 40 mm shall be used. The smaller diameter
(25,0 mm or 25,4 mm) shall be preferred where possible.
Specimen A (see Figure 2) consists of a substrate block, to which the coating is frontally applied, and
the loading block which is glued to the surface of the thermally sprayed coating.
Specimen B (see Figure 3) consists of two loading blocks and a test disc. The test disc coated on one side
is glued to the two loading blocks.
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
Dimensions in millimetres
Key
1 loading block
2 adhesive bond
3 coating
4 substrate block
Figure 2 — Specimen A for tensile test
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
Dimensions in millimetres
Key
1 loading block
2 adhesive bond
3 coating
4 disc (according to Figure 6)
Figure 3 — Specimen B for tensile test
6.2 Material of the specimen
The same material (and surface preparation) shall be used for the specimens as for the actual
component. If this is not feasible, a material shall be used which is comparable in strength, chemical
and physical properties to the material of the component. Identical surface preparation and coating
conditions shall be used.
If the substrate and loading blocks used are made of materials which are prone to work hardening, the
deformation of screw threads inside the blocks might lead to invalid results. The acceptance should be
arithmetically proofed.
6.3 Preparing the substrate and loading blocks
The parts for the tensile test specimen (loading and substrate blocks) are to be manufactured according
to Figure 4. In the case of the test disc, manufacture shall be realized according to Figure 6.
The frontal faces of the blocks or that of the test disc shall be perpendicular to the longitudinal axis.
This can be assured using a bevelling edge square.
The flat faces of the test disc according to form B shall be flat and parallel. For details, see Figure 6.
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
The M16 threaded hole shall be concentric and coaxial to the axis of the cylinder in order to achieve a
pure tensile loading.
Each substrate and loading block as well as each test disc used shall be clearly designated for
identification. Designation should be carried out in such a way that this does not have a negative
influence on the test procedure. Identification and material designation of the specimen shall be
recorded in the test report. The coating face shall not be marked.
Proof that the test blocks are within the required tolerances can be realized using commercial
measuring instruments (for details, see Figure 4 and Figure 5). The gauge shown in Figure B.3 can
be employed in order to measure the parallelism. Repeated use of substrate and loading blocks is
acceptable, as long as the outer diameter is within the tolerances. The length shall not fall below 50 mm
and deformation of the M16 thread due to work hardening shall not influence the results.
In the case of repeated use of substrate and loading blocks made of materials prone to work hardening,
thread inserts shall be used.
NOTE The steps required for manufacture of the test blocks, according to form A and form B, and their
tensile adhesive test procedures are listed in Annex A. This includes different categories of bonding agents:
— A.1: Instructions for single-part and multi-part epoxy bonding agents;
— A.2: Instructions for hardening epoxy-foil bonding agents.
Dimensions in millimetres
Key
a
Flat and square.
b
Sharp-edged.
Figure 4 — Dimensions and tolerances of substrate and loading block (for 25 mm specimen
diameter)
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SIST EN ISO 14916:2017
ISO 14916:2017(E)
Dimensions in millimetres
Figure 5 — Tolerance of parallelism for the tensile adhesive specimen form A exemplary shown
Dimensions in millimetres
Figure 6 — Dimensions and tolerances for test disc with rated diameters 25,0 mm and 25,4 mm
6.4 Preparing and spraying of the specimen
The front face of the substrate block (made out of the specified substrate material) shall be prepared
for deposition of the coating according to the specifications of the corresponding part, respectively
the corresponding component, or according to EN 13507. Contamination (e.g. dirt, fat, and oil) shall be
removed carefully. A rounding of the edges due to the blasting process is to be avoided. Subsequently, the
coating shall be applied. If the outer cylindrical surface of the specimen cannot be kept free of powder
particles, it has to be cleaned. The sequence of spraying process, spraying parameters and spraying
material (for both bond and top coat) shall be used according to the specifications of the corresponding
part, respectively that of the component.
To avoid negatively affecting the tensile testing procedure when substrate and loading blocks are used
repeatedly, any bonding agent residues on the outer cylindrical surfaces of blocks shall be removed
carefully; otherwise, the required centring of the specimen in the V-block may not be possible.
Machined/mechanical removal of remaining bonding agent would inadmissibly reduce the diam
...
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