EN ISO 12679:2015
(Main)Thermal spraying - Recommendations for thermal spraying (ISO 12679:2011)
Thermal spraying - Recommendations for thermal spraying (ISO 12679:2011)
ISO 12679:2011 includes general guidelines for the workmanlike production of metallic, metal-ceramic, oxide-ceramic and plastic coatings, by means of thermal spraying on metallic and non-metallic parent materials.
ISO 12679:2011 provides recommendations for an appropriate and practical spray set-up, faultless manufacturing, monitoring, quality assurance and for non-destructive and destructive tests on the component and accompanying specimen. It describes details about negative effects which can occur. It also gives advice on how to prevent such effects.
Permissible coating loads and evaluation categories for quality are not the subject of ISO 12679:2011, as they are dependent on the operating conditions.
ISO 12679:2011 can be used for contract purposes.
Thermisches Spritzen - Empfehlungen für das thermische Spritzen (ISO 12679:2011)
Projection thermique - Recommandations pour la projection thermique (ISO 12679:2011)
L'ISO 12679:2011 comprend des lignes directrices pour la production, selon les règles de l'art, de revêtements métalliques, métallo-céramiques, oxydo-céramiques et plastiques, par projection thermique sur des matériaux de base métalliques et non métalliques.
L'ISO 12679:2011 fournit des recommandations pour une configuration de projection appropriée et pratique, une production, une surveillance et une assurance qualité irréprochables, ainsi que pour des essais non destructifs et des essais destructifs sur l'élément et sur l'éprouvette associée. Elle décrit en détail les effets indésirables susceptibles de se produire. Elle donne également des conseils sur la manière de prévenir de tels effets.
Les charges admissibles sur les revêtements et les catégories d'évaluation pour la qualité ne relèvent pas du domaine d'application de la présente Norme internationale, car elles dépendent des conditions de service.
L'ISO 12679:2011 peut être utilisée à des fins contractuelles.
Vroče brizganje - Priporočila za vroče brizganje (ISO 12679:2011)
Ta standard vsebuje splošna pravila za profesionalno proizvodnjo kovinskih, kovinsko-keramičnih, oksidno-keramičnih in sintetičnih premazov materialov na kovinskih in nekovinskih podlagah, nanesenih z vročim brizganjem.
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2016
1DGRPHãþD
SIST EN 14616:2005
9URþHEUL]JDQMH3ULSRURþLOD]DYURþHEUL]JDQMH ,62
Thermal spraying - Recommendations for thermal spraying (ISO 12679:2011)
Thermisches Spritzen - Empfehlungen für das thermische Spritzen (ISO 12679:2011)
Projection thermique - Recommandations pour la projection thermique (ISO 12679:2011)
Ta slovenski standard je istoveten z: EN ISO 12679:2015
ICS:
25.220.20 Površinska obdelava Surface treatment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 12679
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2015
EUROPÄISCHE NORM
ICS 25.220.20 Supersedes EN 14616:2004
English Version
Thermal spraying - Recommendations for thermal
spraying (ISO 12679:2011)
Projection thermique - Recommandations pour la Thermisches Spritzen - Empfehlungen für das
projection thermique (ISO 12679:2011) thermische Spritzen (ISO 12679:2011)
This European Standard was approved by CEN on 27 September 2015.
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, 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
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 12679:2015 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
The text of ISO 12679:2011 has been prepared by Technical Committee ISO/TC 107 “Metallic and other
inorganic coatings” of the International Organization for Standardization (ISO) and has been taken over
as EN ISO 12679:2015 by 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 April 2016, and conflicting national standards shall be
withdrawn at the latest by April 2016.
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 14616:2004.
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, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 12679:2011 has been approved by CEN as EN ISO 12679:2015 without any modification.
INTERNATIONAL ISO
STANDARD 12679
First edition
2011-09-15
Thermal spraying — Recommendations
for thermal spraying
Projection thermique — Recommandations pour la projection thermique
Reference number
ISO 12679:2011(E)
©
ISO 2011
ISO 12679:2011(E)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2011 – All rights reserved
ISO 12679:2011(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Parent material . 2
5 Component geometry . 3
6 Spray materials . 3
6.1 General . 3
6.2 Selection of spray materials . 3
6.3 Supply, handling and storage . 4
7 Gases for spraying . 4
8 Liquid fuels for spraying . 5
9 Spray equipment . 5
9.1 General . 5
9.2 Spray device . 5
9.3 Mechanical equipment, rotating devices, handling systems, robots . 5
9.4 Essential auxiliary equipment . 5
10 Surface preparation prior to spraying . 6
10.1 General . 6
10.2 General pretreatments, degreasing, cleaning . 6
10.3 Grit-blasting and other preparation methods . 6
10.4 Covering, masking of areas not to be coated . 7
11 Thermal spraying procedure . 7
11.1 Spraying procedure specification . 7
11.2 Applying the spraying process . 8
12 Post-treatment of the coating . 9
13 Health, safety and environmental aspects .10
14 Recommendations for quality assurance .10
14.1 Quality-assurance measures .10
14.2 Personnel qualification .12
15 Testing of components and accompanying specimens .12
15.1 General .12
15.2 Tests on the component itself .12
Bibliography .14
ISO 12679:2011(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 12679 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings.
iv © ISO 2011 – All rights reserved
ISO 12679:2011(E)
Introduction
Thermal spraying encompasses processes used in the production of coatings and free-standing bodies for which
spray materials are surface-melted, melted off or melted and then propelled onto suitably prepared workpiece
surfaces. The workpiece surfaces are not surface-melted. In order to achieve specific coating properties, the
spray coating can undergo additional post-treatment, either thermal or otherwise, for example, sealing.
Thermally sprayed coatings serve to improve the surface properties of a workpiece by manufacturing or repair
operations. This can be done, for example, in relation to wear, corrosion, heat transfer or heat insulation,
electrical conductivity or insulation, appearance and/or for restoring the part to working order. In certain cases,
a spray coating can render a surface solderable.
Chiefly due to their bonding mechanism, thermally sprayed coatings without thermal post-treatment can be
distinguished from coatings applied with other processes, such as deposition welding, brazing, physical vapour
deposition (PVD) or chemical vapour deposition (CVD).
The advantages of thermal spraying are the following.
— The workpieces to be coated are only slightly heated so that distortion and any other undesired structural
changes to the parent material are avoided. This does not apply if the coatings are thermally treated during
or after the spraying process.
— The application is not dependent on the size of the workpiece or component. The operation can be
stationary or mobile depending on the spraying process.
— Even geometrically complex components can be coated using the appropriate spray set-up.
— The untreated surface of spray coatings generally provides a good bond coat for painting.
— Depending on the spraying process and spray material, different coating thicknesses can be applied,
although a coating thickness of approximately 10 µm is currently considered to be the lower limit.
Process-related disadvantages are as follows:
— the bond strength of thermally sprayed coatings without thermal post-treatment derives from adhesive
forces only;
— the bond strength can be influenced due to an expansion mismatch between the coating and substrate
material, especially in the case of a high operation temperature;
— spray coatings are micro-porous;
— the thicker the spray coating, the higher the residual stresses in the coating, and the degree of multi-axial
stress thus increases;
— spray coatings without additional thermal post-treatment are sensitive to edge pressure, localized and
linear loads and to impact stresses;
— there are restrictions in relation to the geometric dimensions, for example, for the inner coatings of
workpieces whose inner diameter is too small.
INTERNATIONAL STANDARD ISO 12679:2011(E)
Thermal spraying — Recommendations for thermal spraying
1 Scope
This International Standard includes general guidelines for the workmanlike production of metallic,
metal-ceramic, oxide-ceramic and plastic coatings, by means of thermal spraying on metallic and non-metallic
parent materials.
This International Standard provides recommendations for an appropriate and practical spray set-up, faultless
manufacturing, monitoring, quality assurance and for non-destructive and destructive tests on the component
and accompanying specimen. It describes details about negative effects which can occur. It also gives advice
on how to prevent such effects.
Permissible coating loads and evaluation categories for quality are not the subject of this International Standard,
as they are dependent on the operating conditions.
This International Standard can be used for contract purposes.
2 Normative references
The following referenced documents are indispensable for the application 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 3452-1, Non-destructive testing — Penetrant testing — Part 1: General principles
ISO 14231, Thermal spraying — Acceptance inspection of thermal spraying equipment
ISO 14232, Thermal spraying — Powders — Composition and technical supply conditions
ISO 14918, Thermal spraying — Approval testing of thermal sprayers
ISO 14919, Thermal spraying — Wires, rods and cords for flame and arc spraying — Classification — Technical
supply conditions
ISO 14920, Thermal spraying — Spraying and fusing of self-fluxing alloys
ISO 14921, Thermal spraying — Procedures for the application of thermally sprayed coatings for
engineering components
ISO 14922-1, Thermal spraying — Quality requirements of thermally sprayed structures — Part 1: Guidance
for selection and use
ISO 14922-2, Thermal spraying — Quality requirements of thermally sprayed structures — Part 2: Comprehensive
quality requirements
ISO 14922-3, Thermal spraying — Quality requirements of thermally sprayed structures — Part 3: Standard
quality requirements
ISO 14922-4, Thermal spraying — Quality requirements of thermally sprayed structures — Part 4: Elementary
quality requirements
ISO 14923, Thermal spraying — Characterization and testing of thermally sprayed coatings
ISO 14924, Thermal spraying — Post-treatment and finishing of thermally sprayed coatings
ISO 12679:2011(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
shot-peening effect
pressure strengthening by grit-blasting
3.2
sound pressure level
mean value of emitted sound
NOTE Sound pressure level is measured in decibels (dB).
3.3
etching
removing of surface material
NOTE Etching can be applied using liquid agents (wet chemical etching) or using gases in a recipient (dry etching,
plasma etching). The etching agent reacts chemically with the substrate.
3.4
ion-etching
material removed by shooting the surface with high-energetic particles like ions
NOTE The ions cut off material at the impact point. The procedure is used in plasma technology application (vacuum
coating technology).
3.5
corona discharge
dielectric discharge in air after exceeding the break-down field intensity; air molecules will be ionized by
generating short-living ozone
4 Parent material
Virtually every kind of solid-state material can be coated by means of thermal spraying, provided its surface
is suitably prepared. The achievable bond strength of the coating to the substrate is dependent on the spray
material, spraying process and the physical and technological properties of the parent material used. The bond
strength, amongst other things, is particularly influenced by the thermal conductivity of the parent material in
comparison to the conductivity of the spray coating and the state of the parent material’s surface. In general,
hardened materials need a bond coat to give adequate bond strength. The possible coating thickness may be
limited, depending on the bonding material being used. Certain surface-hardening processes, e.g. “nitriding”,
may leave gaseous inclusions which would prevent proper bonding.
A variety of plastics, as well as glass and paper, can be thermally sprayed when using the appropriate spraying
process and a surface treatment method adapted for the respective material.
As the workpieces to be coated by means of thermal spraying are generally only slightly heated, undesired
structural changes to the parent material and changes to the component’s geometry due to distortion are
avoided to the greatest possible extent. However, distortions resulting from intensive grit-blasting during
surface preparation, especially with thin-walled parts or as a result of residual compressive stresses on the
surface of the substrate caused by process-related shot-peening effects, can occur. If coatings are thermally
treated during spraying (processes with simultaneous fusing) or subsequently, undesired structural changes
and significant geometric changes can occur.
For purposes of quality assurance during the manufacturing process, the parent materials and components to be
coated should be stored in such a way that damage and/or undesired changes to the shape or surface are avoided.
2 © ISO 2011 – All rights reserved
ISO 12679:2011(E)
5 Component geometry
The application of thermal spraying is independent, to the greatest possible extent, of the size of the workpiece
or component to be coated. This is mainly true for flame and arc spraying. For plasma and HVOF (high-velocity
oxygen fuel) spraying, closed-off spray booths are normally required due to the high noise and dust emissions.
As a result, there may be restrictions to size of the component.
Certain prerequisites concerning the practical set-up shall be considered when using thermal spraying. If these
rules are followed, even complex geometric parts can be coated with expertise. The most important rules can
be summarized as follows:
— the area to be coated shall be accessible to the spray gun with all its electrical and/or gas connections,
and the necessary spray distance and spray angle shall be maintained;
— sharp edges should be avoided; they cannot be covered with a spray coating;
— narrow radii should be avoided, otherwise turbulence in the spray jet can occur, which can lead to
unsatisfactory coatings in terms of bond strength and density;
— problems with turbulence and undesired, loose particles sticking to the walls occur especially when
spraying in narrow bores or blind holes;
— to prevent the coating from spalling, it has proved advantageous to pull the coating around rounded or
chamfered edges;
— the arguments listed for thermal spraying, i.e. accessibility, sharp edges, narrow radii, bores and blind
holes, also apply to grit-blasting when preparing the surface to be sprayed.
6 Spray materials
6.1 General
The spray materials used for thermal spraying cover a wide range of very different materials. It is virtually
possible to spray any material which can be produced as a solid wire, cored wire, rod, cord or powder, and
which does not sublimate in the arc or plasma or decompose when passing through the flame. In the special
case of molten-bath spraying, the material is processed in its liquid state.
Generally, the following spray materials can be used for thermal spraying:
— metals and metal alloys;
— metal ceramics;
— hard phases embedded in a matrix material;
— oxide ceramics, plastics, as well as various hybrid materials.
6.2 Selection of spray materials
An important task for the designer and/or person responsible for the spray technology is the selection of the
spray material which is most suited to the application. Fundamental to the selection are the demand’s profile
of the coating, the subsequent operating conditions and the most suitable spraying process. Corrosion and/or
wear loads, for example, can determine the demand’s profile. The operating conditions in a tribological system
can be determined by an increased operating temperature or by operating temperatures which fluctuate in level
and, in some cases, also in speed. The most suitable spraying process distinguishes itself in terms of its ability
to fulfil coating requirements, such as density, bond strength, porosity, purity, etc. Here, the relevant process
data, such as temperature level in the flame, in the arc or in the plasma, the dwell time of the spray particles in
the hot zone and the particle velocity in flight and on impact on the substrate, play a decisive role.
ISO 12679:2011(E)
The most important spray materials have been standardized. The following are specified in standards: chemical
composition of the material and its supply form as powder with its special features based on the manufacturing
process, particle shape and particle size distribution, or as wire, rod or cord.
The following International Standards apply:
— for powder: ISO 14232;
— for wires, rods and cords: ISO 14919.
6.3 Supply, handling and storage
The supply form and its constancy from batch to batch, especially with spray powders, plays a fundamental role
in ensuring a uniform quality for the finished coating. For this reason, it is recommended that manufacturing,
supply and distribution be assessed and monitored by a suitable quality-management system. Details
concerning such a procedure are described in EN 12074.
7 Gases for spraying
Industrial gases are used in all thermal spraying processes. Depending on the spraying process, these gases or
their mixtures are employed as a fuel, combustion accelerator, plasma gas, shroud gas, propelling or atomizing
gas, powder-feed gas, or for cooling the part to be coated or even the spray gun.
The physical and chemical characteristics of the industrial gases used for thermal spraying differ quite markedly
from each other. Paying attention to these parameters, a gas or gas mixture, which fulfils the process and
material requirements, can be selected for any thermal spray application.
The following gases are mainly used:
— as a fuel gas: acetylene (C H ), propane (C H ), propylene (C H ), ethene (C H ), hydrogen (H ), natural gas;
2 2 3 8 3 6 2 4 2
— as a plasma gas: argon (Ar), helium (He), hydrogen (H ), nitrogen (N ) and their mixtures;
2 2
— as a combustion accelerator: oxygen (O );
— as a shroud gas: argon (Ar), nitrogen (N );
— as a propelling or atomizing gas: compressed air, nitrogen (N ), argon (Ar);
— as a powder-feed gas: argon (Ar), nitrogen (N );
— for cooling: compressed air, carbon dioxide (CO ).
Depending on the spraying process and the purpose of the application, varying high-purity levels are demanded
of the gases. The gas producer is responsible for the gas purity whose level shall then be maintained at the
user’s premises during the filling process, transport and withdrawal, and in the pipeline system.
In general, it is sufficient to indicate the purity of the gases used in thermal spraying with numerical values
according to the number of “nines” before and after the point (4,6 = 99,996 %). Typical gas purities for thermal
spraying are:
— Ethene 3,5
— Oxygen 3,5
— Hydrogen 3,0
— Nitrogen 4,6
— Argon 4,6
— Helium 4,6
4 © ISO 2011 – All rights reserved
ISO 12679:2011(E)
For plasma spraying in particular, the purity of the gases has a big influence on the lifetime of the nozzle
electrode system.
8 Liquid fuels for spraying
In several applications, the high-velocity flame spraying process is applied using liquid fuels, e.g. kerosene,
N-paraffin, test benzene or petroleum. A low sulfur content has to be kept due to environmental reasons. Flash point,
evaporation point and purity have to be considered, as well as additional instructions from the equipment supplier.
9 Spray equipment
9.1 General
The thermal spray equipment includes the spray device with all the electrical and gas supply and regulating
equipment, possibly the handling system, plus the peripheral installations such as exhaust and filter systems,
spray booth and soundproofing. Modern installations often include additional equipment for monitoring spray
parameters and motion sequences by means of video cameras.
9.2 Spray device
The spray device is defined in ISO 14917 as the equipment required for thermal spraying.
Guidelines can be found in ISO 14231 for the qualification of the spraying installation including the transport
system for the spray material. ISO 14231 can also be consulted when monitoring the state of the thermal
spraying installation.
9.3 Mechanical equipment, rotating devices, handling systems, robots
In addition to the spray parameters for melting and melting off and for the transport of the spray material,
the distance, setting angle and relative motion between the gun and workpiece have a decisive influence on
the quality of the spray coating. In order to maintain these parameters as closely as possible, a mechanized
spraying process should be used wherever possible rather than a manual one.
A handling system should fulfil the following requirements:
— capable of movements, speed and positioning with accuracy values appropriate to the application;
— sufficient static and dynamic loading capacity;
— stabilization of spray distance;
— non-susceptibility of control and regulation systems to influences from spray operation, for example, when
igniting the plasma burner, and in relation to spray dust and heat from the flame, arc or plasma jet;
— simple and straightforward setting and programming of the handling system or rotating device.
9.4 Essential auxiliary equipment
Auxiliary equipment essential for thermal spraying includes equipment for cooling the burner system and
possibly the energy supply, too, f
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