EN 4704:2012

Aerospace series - Tartaric-Sulphuric-Acid anodizing of aluminium and aluminium wrought alloys for corrosion protection and paint pre-treatment (TSA)

This European Standard defines the requirement for Tartaric-Sulphuric-Acid (TSA) anodizing of aluminium and wrought alloys for corrosion protection and paint pre-treatment.
The purpose of this European Standard is to give design and quality requirements to manufactures.

Luft- und Raumfahrt - Weinsäure-Schwefelsäure-Anodisieren (TSA) von Aluminium und Aluminium-Knetlegierungen für den Korrosionsschutz und zur Vorbehandlung

Série aérospatiale - Anodisation tartrique de l'aluminium et des alliages d'aluminium corroyés pour protection contre la corrosion et peinture (TSA)

La présente Norme européenne définit les exigences de l’anodisation tartrique sulfurique de l’aluminium et des alliages corroyés pour la protection contre la corrosion et le prétraitement de la peinture.
Le but de la présente Norme européenne est de fournir les exigences de conception et de qualité aux fabricants.

Aeronavtika - Eloksiranje aluminija in gnetljivih (kovnih) aluminijskih zlitin z vinsko-žvepleno kislino (TSA) za korozijsko zaščito in barvno predobdelavo

Ta evropski standard določa zahtevo za eloksiranje aluminija in gnetljivih (kovnih) aluminijevih zlitin z vinsko-žvepleno kislino (TSA) za korozijsko zaščito in barvno predobdelavo. Namen tega evropskega standarda je določiti zahteve za proizvajalce glede zasnove in kakovosti.

General Information

• Status: Published
• Publication Date: 07-Feb-2012
• Withdrawal Date: 30-Aug-2012
• ICS: 49.040 - Coatings and related processes used in aerospace industry
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 5 - Non-Metallic
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Completion Date: 30-Jun-2017
• Ref Project: SIST EN 4704:2012 - Aerospace series - Tartaric-Sulphuric-Acid anodizing of aluminium and aluminium wrought alloys for corrosion protection and paint pre-treatment (TSA)

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2012
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Aerospace series - Tartaric-Sulphuric-Acid anodizing of aluminium and aluminium
wrought alloys for corrosion protection and paint pre-treatment (TSA)
Luft- und Raumfahrt - Weinsäure-Schwefelsäure-Anodisieren (TSA) von Aluminium und
Aluminium-Knetlegierungen für den Korrosionsschutz und zur Vorbehandlung
Série aérospatiale - Anodisation tartrique de l'aluminium et des alliages d'aluminium
corroyés pour protection contre la corrosion et peinture (TSA)
Ta slovenski standard je istoveten z: EN 4704:2012
ICS:
49.025.20 Aluminij Aluminium
49.040 Prevleke in z njimi povezani Coatings and related
postopki, ki se uporabljajo v processes used in aerospace
letalski in vesoljski industriji industry
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 4704
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2012
ICS 49.040
English Version
Aerospace series - Tartaric-Sulphuric-Acid anodizing of
aluminium and aluminium wrought alloys for corrosion protection
and paint pre-treatment (TSA)
Série aérospatiale - Anodisation tartrique de l'aluminium et Luft- und Raumfahrt - Weinsäure-Schwefelsäure-
des alliages d'aluminium corroyés pour protection contre la Anodisieren (TSA) von Aluminium und Aluminium-
corrosion et peinture (TSA) Knetlegierungen für den Korrosionsschutz und zur
Vorbehandlung
This European Standard was approved by CEN on 23 December 2011.

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, 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

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4704:2012: E
worldwide for CEN national Members.

Contents Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Principle .5
5 Requirements .6
6 Re-anodizing . 10
7 Qualification Test Report (QTR) . 11
Annex A (informative) Wöhler curves and stress levels – Reference fatigue curves . 12
Bibliography . 13

Foreword
This document (EN 4704:2012) has been prepared by the Aerospace and Defence Industries Association of
Europe - Standardization (ASD-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has
received the approval of the National Associations and the Official Services of the member countries of ASD,
prior to its presentation to CEN.
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 August 2012, and conflicting national standards shall be withdrawn at
the latest by August 2012.
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.
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, 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.
1 Scope
This European Standard defines the requirement for Tartaric-Sulphuric-Acid (TSA) anodizing of aluminium
and wrought alloys for corrosion protection and paint pre-treatment.
The purpose of this European Standard is to give design and quality requirements to manufactures.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 2101, Aerospace series — Chromic acid anodizing of aluminium and wrought aluminium alloys
EN 3665, Aerospace series — Test methods for paints and varnishes — Filiform corrosion resistance test on
aluminium alloys
EN 6072, Aerospace series — Metallic materials — Test methods — Constant amplitude fatique testing
EN ISO 2106, Anodizing of aluminium and its alloys — Determination of mass per unit area (surface density)
of anodic oxidation coatings — Gravimetric method (ISO 2106:2011)
EN ISO 2409, Paints and varnishes — Cross-cut test (ISO 2409)
EN ISO 9227 Corrosion tests in artificial atmospheres — Salt spray tests (ISO 9227)
EN ISO 15528, Paints, varnishes and raw materials for paints and varnishes — Sampling (ISO 15528)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
de-anodizing
process, which removes the anodic oxide
3.2
smut
precipitations of alloying elements (e. g. Cu, Fe, Zn, Si) on the surface of parts after a process step normally
after alkaline etching step
3.3
Mechanically Disturbed Layer
MDL
layer that is present at the surface resulting from the rolling process of the material
3.4
pit
surface corrosion defect at which the anodic coating is penetrated
3.5
process instruction
document that describes the detailed process, parameters, detailed steps, etc.
3.6
alloys
all aluminium alloys, that are treated with the TSA process in the specific shop
3.7
re-anodizing
repetition of the anodizing process step after complete de-anodizing
3.8
sealing
sealing (of the anodized layers) is applied to close the pores produced by the acid anodizing process. It is
usually applied in demineralized water bath. Sealing can improve the corrosion resistance performance of the
anodic film.
3.9
dichromate sealing
the dichromate sealing process has to be applied for unpainted parts
It content one of the following products:
 Sodium dichromate;
 Potassium dichromate.
It includes chromate and has to be replaced by a chromium III chemical conversion coating when available.
4 Principle
4.1 General description of process
TSA process is an electrochemical process used for generating an aluminium oxide layer for corrosion
protection and surface treatment prior to application of a corrosion-inhibiting primer.
The TSA process is characterized by using an electrolyte composed of tartaric and sulphuric acid. Suitable
surface preparation steps, e. g. alkaline cleaning, alkaline etching, acidic pickling/desmutting and subsequent
steps such as rinsing (and sealing, if applicable), have to be defined and are integral to the TSA process.
4.2 Limitations
All processes that can compromise the anodic film such as forming, or heat-treatment shall be performed prior
to surface preparation of the parts to be anodized.
TSA anodizing shall not be applied:
 for metal bonding applications;
 inside of oxygen pipes;
 for tubes, pipes and open holes with a length to diameter ratio higher than 10:1;
 for trapped holes with a length to a diameter ratio greater than 5:1;
 for parts or assemblies (e.g. spot-welded and riveted), which can permanently entrap;
 for components which can permanently entrap treatment solutions, except components that can be
adequately masked.
NOTE The formation of oxide layer influ
...