Anodizing of aluminium and its alloys -- Specification for hard anodic oxidation coatings on aluminium and its alloys

This document specifies requirements for hard anodic oxidation coatings on aluminium and its alloys, including test methods. It also specifies the information to be supplied by the customer to the anodizer (see Annex A). It is not applicable to coatings produced by processes such as those referred to as plasma electrolytic oxidation, micro-arc oxidation, plasma-chemical anodic oxidation, anodic spark deposition or spark anodizing.

Anodisation de l'aluminium et de ses alliages -- Spécification pour l'anodisation dure de l'aluminium et des alliages d'aluminium

General Information

Status
Published
Publication Date
24-May-2021
Current Stage
5060 - Close of voting Proof returned by Secretariat
Start Date
15-Apr-2021
Completion Date
14-Apr-2021
Ref Project

RELATIONS

Buy Standard

Standard
ISO 10074:2021 - Anodizing of aluminium and its alloys -- Specification for hard anodic oxidation coatings on aluminium and its alloys
English language
18 pages
sale 15% off
Preview
sale 15% off
Preview
Draft
ISO/FDIS 10074:Version 12-feb-2021 - Anodizing of aluminium and its alloys -- Specification for hard anodic oxidation coatings on aluminium and its alloys
English language
18 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 10074
Fourth edition
2021-05
Anodizing of aluminium and its
alloys — Specification for hard anodic
oxidation coatings on aluminium and
its alloys
Anodisation de l'aluminium et de ses alliages — Spécification pour
l'anodisation dure de l'aluminium et des alliages d'aluminium
Reference number
ISO 10074:2021(E)
ISO 2021
---------------------- Page: 1 ----------------------
ISO 10074:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 10074:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2  Normative references ...................................................................................................................................................................................... 1

3  Terms and definitions ..................................................................................................................................................................................... 1

4  Material classification ..................................................................................................................................................................................... 2

5  Appearance ................................................................................................................................................................................................................ 2

6  Thickness ..................................................................................................................................................................................................................... 2

7  Surface density ....................................................................................................................................................................................................... 2

8  Resistance to wear/abrasion ................................................................................................................................................................... 3

8.1 General ........................................................................................................................................................................................................... 3

8.2 Abrasive wheel wear test method .......................................................................................................................................... 3

8.3 Abrasive jet test method ................................................................................................................................................................. 4

8.4 Taber abrasion test method ......................................................................................................................................................... 5

9  Vickers microhardness .................................................................................................................................................................................. 5

10  Resistance to corrosion ................................................................................................................................................................................. 6

Annex A (normative) Information to be supplied by the customer to the anodizer ...........................................7

Annex B (normative) Abrasion test ....................................................................................................................................................................... 8

Annex C (normative) Preparation of standard specimen ............................................................................................................11

Annex D (informative) Sampling procedures ...........................................................................................................................................12

Annex E (normative) Breakdown voltage.....................................................................................................................................................13

Annex F (normative) Process qualification and approval ...........................................................................................................14

Annex G (informative) Packaging and delivery of anodized articles ...............................................................................15

Annex H (informative) Processing guidance .............................................................................................................................................16

Bibliography .............................................................................................................................................................................................................................18

© ISO 2021 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 10074:2021(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 of 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 www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 79, Light metals and their alloys,

Subcommittee SC 2, Organic and anodic oxidation coatings on aluminium.

This fourth edition cancels and replaces the third edition (ISO 10074:2017), which has been technically

revised. The main changes compared with the previous edition are as follows:

— pretest abrasion test numbers have been added as requirements to the abrasive wheel wear test.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 10074:2021(E)
Introduction

Hard anodizing is an electrolytic treatment which results in the formation of a hard and usually thick

coating of alumina used primarily for engineering purposes.

Hard anodizing can be applied to cast or wrought aluminium and aluminium alloys; however,

alloys containing more than 5 % copper and/or 8 % silicon and die casting alloys require special

anodizing procedures. To obtain optimum microhardness, wear resistance or low surface roughness

characteristics, low contents of alloy are selected.

Unless otherwise specified, articles are anodized after all heat-treatment, machining, welding, forming

and perforating operations. The best results are achieved on machined surfaces. Sharp edges are

machined to a radius of at least 10 times the intended thickness to avoid “burning” and/or spalling.

Hard anodizing will usually result in a dimensional increase on each surface equal to about 50 % of the

coating thickness. The dimensions of the component prior to anodizing will allow for this, if necessary.

The thickness is generally within the range of 25 μm to 150 μm. Low thickness (up to 25 μm) is

sometimes used in a variety of applications, such as splines and threads. Normal thickness (50 μm

to 80 μm) is used for wear or insulation requirements. High thickness (150 μm) is used for repairing

purposes, but thick coatings tend to be softer in outer regions. Very hard coatings reduce the fatigue

strength. This phenomenon can be minimized by applying shot peening before hard anodizing (see H.6),

by reducing thickness and/or by sealing. Hard anodizing tends to increase surface roughness. This can

be limited with low alloy contents and/or mechanical finishing.
Hard anodic oxidation coatings are mainly used to obtain the following:
— resistance to wear through abrasion or erosion;
— electrical insulation;
— thermal insulation;
— build-up (to repair parts out of tolerance on machining or worn parts);
— resistance to corrosion (when sealed).
© ISO 2021 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 10074:2021(E)
Anodizing of aluminium and its alloys — Specification for
hard anodic oxidation coatings on aluminium and its alloys
1 Scope

This document specifies requirements for hard anodic oxidation coatings on aluminium and its alloys,

including test methods.

It also specifies the information to be supplied by the customer to the anodizer (see Annex A).

It is not applicable to coatings produced by processes such as those referred to as plasma electrolytic

oxidation, micro-arc oxidation, plasma-chemical anodic oxidation, anodic spark deposition or spark

anodizing.
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 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method

ISO 2106, Anodizing of aluminium and its alloys — Determination of mass per unit area (surface density) of

anodic oxidation coatings — Gravimetric method

ISO 2360, Non-conductive coatings on non-magnetic electrically conductive base metals — Measurement

of coating thickness — Amplitude-sensitive eddy-current method

ISO 2376, Anodizing of aluminium and its alloys — Determination of breakdown voltage and withstand

voltage

ISO 4516, Metallic and other inorganic coatings — Vickers and Knoop microhardness tests

ISO 6344-1, Coated abrasives — Grain size analysis — Part 1: Grain size distribution test

ISO 7583, Anodizing of aluminium and its alloys — Terms and definitions

ISO 8251, Anodizing of aluminium and its alloys — Measurement of abrasion resistance of anodic oxidation

coatings
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
3  Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 7583 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
lot
articles of the same nominal composition and temper which are processed together
© ISO 2021 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 10074:2021(E)
3.2
lot acceptance test

test on a production lot (3.1) to determine its conformity to specified requirements

4  Material classification

The properties and characteristics of hard anodic oxidation coatings are significantly affected by both

the alloy and the method of production.

Consequently, for the purposes of this document, materials are classified into five alloy groupings as

follows.
— Class 1: all wrought alloys except those in Class 2.

— Class 2 (a): alloys of the 2 000 series and any other alloys that contain more than 5 % copper.

— Class 2 (b): alloys of the 5 000 series containing 2 % or more magnesium and alloys of the 7 000

series.
— Class 3 (a): casting alloys with less than 2 % copper and/or 8 % silicon.
— Class 3 (b): other casting alloys.

Information to be supplied by the customer to the anodizer shall be in accordance with Annex A.

5  Appearance

The significant surface shall be completely anodized. The visual appearance shall be substantially

uniform. There shall be no spalling, blistering or powdery (burnt) areas. Visual examination shall be a

lot acceptance test.
Crazing or microcracks shall not normally be a reason for rejection.
6  Thickness

Thickness measurements shall be made on the significant surfaces, but not within 5 mm of contact

(jigging) marks, nor in the immediate neighbourhood of a sharp edge.

Measurement shall be made using either the non-destructive eddy current method described in

ISO 2360 or the destructive microscopical method described in ISO 1463. In the case of a dispute, the

microscopical method (ISO 1463) shall be used.

Measurement of thickness or, where relevant, final dimensions shall be dealt with in a lot acceptance

test.
7  Surface density

The surface density (coating mass per unit area), when measured in accordance with ISO 2106 on

unsealed anodic oxidation coatings with a nominal thickness of 50 μm ± 5 μm, shall have the minimum

values given in Table 1.

If the coating thickness is not 50 μm, the surface density shall be corrected proportionately.

WARNING — A method specified in ISO 2106 requires the use of a reagent containing

chromium(VI). Chromium(VI) is toxic and its solutions are hazardous to the environment and

severely hazardous to waters.
2 © ISO 2021 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 10074:2021(E)
Table 1 — Minimum surface density
Material class Minimum acceptable value
Class 1 1 100 mg/dm
Class 2 (a) (b) 950 mg/dm
Class 3 (a) 950 mg/dm
Class 3 (b) By agreement
8  Resistance to wear/abrasion
8.1  General

The resistance to wear/abrasion shall be measured on unsealed anodic oxidation coatings (see NOTE).

Due to good correlation achieved with other properties, resistance to wear/abrasion shall be tested in

accordance with B.1, using the abrasive wheel wear test method described in ISO 8251.

NOTE Resistance to abrasion can be measured on sealed anodic oxidation coatings but hydrothermal sealing

and/or dyeing can reduce the resistance to abrasion/wear by over 50 %.

When the abrasive wheel wear test method is not appropriate (especially on some curved surfaces),

resistance to wear/abrasion shall be tested in accordance with B.2, using the abrasive jet test method

described in ISO 8251. This test gives an average for the total coating thickness.

The abrasive wheel wear test method assesses the resistance to abrasive wear. The abrasive jet

test method assesses the resistance to erosive wear (erosion). Thus, the results are not necessarily

comparable.

The Taber abrasion test method in accordance with B.3 may only be used when specified.

8.2  Abrasive wheel wear test method

The resistance to wear/abrasion shall be determined by the measurement of loss in coating thickness

or loss in coating mass. When determined in accordance with B.1, using the abrasive wheel test

method described in ISO 8251, the final value shall be an average of at least three tests using a load of

19,6 N ± 0,5 N and grade P240 silicon carbide paper (as described in ISO 6344-1). The loss in coating

thickness or in coating mass shall exclude any loss due to the pretest abrasion.

The acceptance values shall be in accordance with Table 2. The standard specimen, in accordance with

Annex C, shall be tested each day, under the same conditions as those used for the test specimen. When

the loss in coating thickness is used, each thickness value shall be the average of 10 readings in the test

area.

The time between hard anodizing and abrasion testing shall be at least 24 h. During this period, the test

specimens shall be stored in the test environment.
© ISO 2021 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO 10074:2021(E)
Table 2 — Acceptance values for abrasive wheel wear test

Alloy Pretest abrasion  Abrasion test  Relative mean specific abrasion resistance

number of double  number of double  acceptance value
strokes strokes % compared to standard specimen (in accordance
ds with Annex C)
Class 1 100 800 ≥80 %
Class 2 (a) 100 400 ≥30 %
Class 2 (b) 100 800 ≥55 %
Class 3 (a) 100 400 ≥55 %
or by agreement (see NOTE)
Class 3 (b) 100 400 ≥20 %

NOTE The relative mean specific abrasion resistance (RMSAR) is given by the formula.

Mean wear resistance of test specimen
RMSAR = × 100
Mean wear resisttance of standard specimen
where the w
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 10074
ISO/TC 79/SC 2
Anodizing of aluminium and its
Secretariat: JISC
alloys — Specification for hard anodic
Voting begins on:
2021­02­17 oxidation coatings on aluminium and
its alloys
Voting terminates on:
2021­04­14
Anodisation de l'aluminium et de ses alliages — Spécification pour
l'anodisation dure de l'aluminium et des alliages d'aluminium
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 SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 10074:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. ISO 2021
---------------------- Page: 1 ----------------------
ISO/FDIS 10074:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

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
CP 401 • Ch. de Blandonnet 8
CH­1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/FDIS 10074:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2  Normative references ...................................................................................................................................................................................... 1

3  Terms and definitions ..................................................................................................................................................................................... 1

4  Material classification ..................................................................................................................................................................................... 2

5  Appearance ................................................................................................................................................................................................................ 2

6  Thickness ..................................................................................................................................................................................................................... 2

7  Surface density ....................................................................................................................................................................................................... 2

8  Resistance to wear/abrasion ................................................................................................................................................................... 3

8.1 General ........................................................................................................................................................................................................... 3

8.2 Abrasive wheel wear test method .......................................................................................................................................... 3

8.3 Abrasive jet test method ................................................................................................................................................................. 4

8.4 Taber abrasion test method ......................................................................................................................................................... 5

9  Vickers microhardness .................................................................................................................................................................................. 5

10  Resistance to corrosion ................................................................................................................................................................................. 6

Annex A (normative) Information to be supplied by the customer to the anodizer ...........................................7

Annex B (normative) Abrasion test ....................................................................................................................................................................... 8

Annex C (normative) Preparation of standard specimen ............................................................................................................11

Annex D (informative) Sampling procedures ...........................................................................................................................................12

Annex E (normative) Breakdown voltage.....................................................................................................................................................13

Annex F (normative) Process qualification and approval ...........................................................................................................14

Annex G (informative) Packaging and delivery of anodized articles ...............................................................................15

Annex H (informative) Processing guidance .............................................................................................................................................16

Bibliography .............................................................................................................................................................................................................................18

© ISO 2021 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/FDIS 10074:2021(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 non­governmental, 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 of 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 www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 79, Light metals and their alloys,

Subcommittee SC 2, Organic and anodic oxidation coatings on aluminium.

This fourth edition cancels and replaces the third edition (ISO 10074:2017), which has been technically

revised. The main changes compared with the previous edition are as follows:

— pretest abrasion test numbers have been added as requirements to the abrasive wheel wear test.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/FDIS 10074:2021(E)
Introduction

Hard anodizing is an electrolytic treatment which results in the formation of a hard and usually thick

coating of alumina used primarily for engineering purposes.

Hard anodizing can be applied to cast or wrought aluminium and aluminium alloys; however,

alloys containing more than 5 % copper and/or 8 % silicon and die casting alloys require special

anodizing procedures. To obtain optimum microhardness, wear resistance or low surface roughness

characteristics, low contents of alloy are selected.

Unless otherwise specified, articles are anodized after all heat-treatment, machining, welding, forming

and perforating operations. The best results are achieved on machined surfaces. Sharp edges are

machined to a radius of at least 10 times the intended thickness to avoid “burning” and/or spalling.

Hard anodizing will usually result in a dimensional increase on each surface equal to about 50 % of the

coating thickness. The dimensions of the component prior to anodizing will allow for this, if necessary.

The thickness is generally within the range of 25 μm to 150 μm. Low thickness (up to 25 μm) is

sometimes used in a variety of applications, such as splines and threads. Normal thickness (50 μm

to 80 μm) is used for wear or insulation requirements. High thickness (150 μm) is used for repairing

purposes, but thick coatings tend to be softer in outer regions. Very hard coatings reduce the fatigue

strength. This phenomenon can be minimized by applying shot peening before hard anodizing (see H.6),

by reducing thickness and/or by sealing. Hard anodizing tends to increase surface roughness. This can

be limited with low alloy contents and/or mechanical finishing.
Hard anodic oxidation coatings are mainly used to obtain the following:
— resistance to wear through abrasion or erosion;
— electrical insulation;
— thermal insulation;
— build-up (to repair parts out of tolerance on machining or worn parts);
— resistance to corrosion (when sealed).
© ISO 2021 – All rights reserved v
---------------------- Page: 5 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 10074:2021(E)
Anodizing of aluminium and its alloys — Specification for
hard anodic oxidation coatings on aluminium and its alloys
1 Scope

This document specifies requirements for hard anodic oxidation coatings on aluminium and its alloys,

including test methods.

It also specifies the information to be supplied by the customer to the anodizer (see Annex A).

It is not applicable to coatings produced by processes such as those referred to as plasma electrolytic

oxidation, micro-arc oxidation, plasma-chemical anodic oxidation, anodic spark deposition or spark

anodizing.
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 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method

ISO 2106, Anodizing of aluminium and its alloys — Determination of mass per unit area (surface density) of

anodic oxidation coatings — Gravimetric method

ISO 2360, Non-conductive coatings on non-magnetic electrically conductive base metals — Measurement

of coating thickness — Amplitude-sensitive eddy-current method

ISO 2376, Anodizing of aluminium and its alloys — Determination of breakdown voltage and withstand

voltage

ISO 4516, Metallic and other inorganic coatings — Vickers and Knoop microhardness tests

ISO 6344­1, Coated abrasives — Grain size analysis — Part 1: Grain size distribution test

ISO 7583, Anodizing of aluminium and its alloys — Terms and definitions

ISO 8251, Anodizing of aluminium and its alloys — Measurement of abrasion resistance of anodic oxidation

coatings
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
3  Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 7583 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
lot
articles of the same nominal composition and temper which are processed together
© ISO 2021 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO/FDIS 10074:2021(E)
3.2
lot acceptance test

test on a production lot (3.1) to determine its conformity to specified requirements

4  Material classification

The properties and characteristics of hard anodic oxidation coatings are significantly affected by both

the alloy and the method of production.

Consequently, for the purposes of this document, materials are classified into five alloy groupings as

follows.
— Class 1: all wrought alloys except those in Class 2.

— Class 2 (a): alloys of the 2 000 series and any other alloys that contain more than 5 % copper.

— Class 2 (b): alloys of the 5 000 series containing 2 % or more magnesium and alloys of the 7 000 series.

— Class 3 (a): casting alloys with less than 2 % copper and/or 8 % silicon.
— Class 3 (b): other casting alloys.

Information to be supplied by the customer to the anodizer shall be in accordance with Annex A.

5  Appearance

The significant surface shall be completely anodized. The visual appearance shall be substantially

uniform. There shall be no spalling, blistering or powdery (burnt) areas. Visual examination shall be a

lot acceptance test.
Crazing or microcracks shall not normally be a reason for rejection.
6  Thickness

Thickness measurements shall be made on the significant surfaces, but not within 5 mm of contact

(jigging) marks, nor in the immediate neighbourhood of a sharp edge.

Measurement shall be made using either the non-destructive eddy current method described in

ISO 2360 or the destructive microscopical method described in ISO 1463. In the case of a dispute, the

microscopical method (ISO 1463) shall be used.

Measurement of thickness or, where relevant, final dimensions shall be dealt with in a lot acceptance test.

7  Surface density

The surface density (coating mass per unit area), when measured in accordance with ISO 2106 on

unsealed anodic oxidation coatings with a nominal thickness of 50 μm ± 5 μm, shall have the minimum

values given in Table 1.

If the coating thickness is not 50 μm, the surface density shall be corrected proportionately.

WARNING — A method specified in ISO 2106 requires the use of a reagent containing

chromium(VI). Chromium(VI) is toxic and its solutions are hazardous to the environment and

severely hazardous to waters.
2 © ISO 2021 – All rights reserved
---------------------- Page: 7 ----------------------
ISO/FDIS 10074:2021(E)
Table 1 — Minimum surface density
Material class Minimum acceptable value
Class 1 1 100 mg/dm
Class 2 (a) (b) 950 mg/dm
Class 3 (a) 950 mg/dm
Class 3 (b) By agreement
8  Resistance to wear/abrasion
8.1  General

The resistance to wear/abrasion shall be measured on unsealed anodic oxidation coatings (see NOTE).

Due to good correlation achieved with other properties, resistance to wear/abrasion shall be tested in

accordance with B.1, using the abrasive wheel wear test method described in ISO 8251.

NOTE Resistance to abrasion can be measured on sealed anodic oxidation coatings but hydrothermal sealing

and/or dyeing can reduce the resistance to abrasion/wear by over 50 %.

When the abrasive wheel wear test method is not appropriate (especially on some curved surfaces),

resistance to wear/abrasion shall be tested in accordance with B.2, using the abrasive jet test method

described in ISO 8251. This test gives an average for the total coating thickness.

The abrasive wheel wear test method assesses the resistance to abrasive wear. The abrasive jet

test method assesses the resistance to erosive wear (erosion). Thus, the results are not necessarily

comparable.

The Taber abrasion test method in accordance with B.3 may only be used when specified.

8.2  Abrasive wheel wear test method

The resistance to wear/abrasion shall be determined by the measurement of loss in coating thickness

or loss in coating mass. When determined in accordance with B.1, using the abrasive wheel test

method described in ISO 8251, the final value shall be an average of at least three tests using a load of

19,6 N ± 0,5 N and grade P240 silicon carbide paper (as described in ISO 6344-1). The loss in coating

thickness or in coating mass shall exclude any loss due to the pretest abrasion.

The acceptance values shall be in accordance with Table 2. The standard specimen, in accordance

with Annex C, shall be tested each day, under the same conditions as those used for the test specimen.

When the loss in coating thickness is used, each thickness value shall be the average of 10 readings in

the test area.

The time between hard anodizing and abrasion testing shall be at least 24 h. During this period, the test

specimens shall be stored in the test environment.
© ISO 2021 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO/FDIS 10074:2021(E)
Table 2 — Acceptance values for abrasive wheel wear test

Alloy Pretest abrasion  Abrasion test  Relative mean specific abrasion resistance ac-

number of dou- number of double  ceptance value
ble strokes strokes % compared to standard specimen (in accordance
ds with Annex C)
Class 1 100 800 ≥ 80 %
Class 2 (a) 100 400 ≥ 30 %
Class 2 (b) 100 800 ≥ 55 %
Clas
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.