SIST EN ISO/ASTM 52911-3:2023
(Main)Additive Manufacturing - Design - Part 3: PBF-EB of metallic materials (ISO/ASTM 52911-3:2023)
Additive Manufacturing - Design - Part 3: PBF-EB of metallic materials (ISO/ASTM 52911-3:2023)
This document specifies the features of electron beam powder bed fusion of metals (EB-PBF-M) and
provides detailed design recommendations.
Some of the fundamental principles are also applicable to other additive manufacturing (AM) processes, provided that due consideration is given to process-specific features. This document also provides a state of the art review of design guidelines associated with the use of powder bed fusion (PBF) by bringing together relevant knowledge about this process and by extending the scope of ISO/ASTM 52910.
Additive Fertigung - Konstruktion - Teil 3: Pulverbettbasiertes Schmelzen von Metallen mittels Elektronenstrahl (ISO/ASTM 52911-3:2023)
Dieses Dokument legt die Merkmale der Elektronenstrahl-Pulverbettfusion von Metallen (PBF-EB/M) fest und bietet detaillierte Konstruktionsempfehlungen.
Einige der grundlegenden Prinzipien gelten auch für andere additive Fertigungsverfahren (AM-Verfahren) angewendet werden, vorausgesetzt, dass die prozessspezifischen Merkmale berücksichtigt werden.
Dieses Dokument bietet eine Überprüfung von Konstruktionsleitfäden auf dem Stand der Technik im Zusammenhang mit pulverbettbasiertem Schmelzen (PBF), indem relevantes Wissen zu diesem Verfahren zusammengeführt und der Anwendungsbereich von ISO/ASTM 52910 erweitert wird.
Fabrication additive - Conception - Partie 3: BF-EB de matériaux métalliques (ISO/ASTM 52911-3:2023)
Le présent document spécifie les caractéristiques de la fusion par faisceau d'électrons sur lit de poudre métallique (PBF-EB/M) et fournit des recommandations de conception détaillées.
Certains des principes fondamentaux sont également applicables à d'autres procédés de fabrication additive (FA), sous réserve que les caractéristiques spécifiques à un procédé soient dûment prises en compte.
Le présent document fournit également un État de l’Art des lignes directrices de conception associées à l’utilisation d’une fusion sur lit de poudre (PBF), en compilant des connaissances pertinentes sur ce procédé et en élargissant le domaine d’application de l’ISO/ASTM 52910.
Aditivna proizvodnja - Konstruiranje - 3. del: Spajanje kovinskega prahu v postelji z elektronskim snopom (PBF-EB) (ISO/ASTM 52911-3:2023)
Ta dokument določa značilnosti fuzije kovinskih prahastih plasti z elektronskim žarkom (EB-PBF-M) in
podaja podrobna priporočila za podrobno načrtovanje.
Nekatera temeljna načela je mogoče uporabiti tudi pri drugih procesih aditivne proizvodnje (AM) pod pogojem, da se upošteva značilnosti procesa. Ta dokument ponuja tudi najsodobnejši pregled smernic za načrtovanje, povezanih z uporabo fuzije prahastih plasti (PFB), ki združujejo ustrezno znanje o tem procesu in razširjajo področje uporabe standarda ISO/ASTM 52910.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO/ASTM 52911-3:2023
01-maj-2023
Aditivna proizvodnja - Konstruiranje - 3. del: Spajanje kovinskega prahu v postelji
z elektronskim snopom (PBF-EB) (ISO/ASTM 52911-3:2023)
Additive Manufacturing - Design - Part 3: PBF-EB of metallic materials (ISO/ASTM
52911-3:2023)
Additive Fertigung - Konstruktion - Teil 3: Pulverbettbasiertes Schmelzen von Metallen
mittels Elektronenstrahl (ISO/ASTM 52911-3:2023)
Fabrication additive - Conception - Partie 3: BF-EB de matériaux métalliques (ISO/ASTM
52911-3:2023)
Ta slovenski standard je istoveten z: EN ISO/ASTM 52911-3:2023
ICS:
25.030 3D-tiskanje Additive manufacturing
SIST EN ISO/ASTM 52911-3:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO/ASTM 52911-3:2023
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SIST EN ISO/ASTM 52911-3:2023
EN ISO/ASTM 52911-3
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2023
EUROPÄISCHE NORM
ICS 25.030
English Version
Additive Manufacturing - Design - Part 3: PBF-EB of
metallic materials (ISO/ASTM 52911-3:2023)
Fabrication additive - Conception - Partie 3: BF-EB de Additive Fertigung - Konstruktion - Teil 3:
matériaux métalliques (ISO/ASTM 52911-3:2023) Pulverbettbasiertes Schmelzen von Metallen mittels
Elektronenstrahl (ISO/ASTM 52911-3:2023)
This European Standard was approved by CEN on 17 February 2023.
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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO/ASTM 52911-3:2023 E
worldwide for CEN national Members.
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SIST EN ISO/ASTM 52911-3:2023
EN ISO/ASTM 52911-3:2023 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO/ASTM 52911-3:2023
EN ISO/ASTM 52911-3:2023 (E)
European foreword
This document (EN ISO/ASTM 52911-3:2023) has been prepared by Technical Committee ISO/TC 261
"Additive manufacturing" in collaboration with Technical Committee CEN/TC 438 “Additive
Manufacturing” the secretariat of which is held by AFNOR.
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 2023, and conflicting national standards
shall be withdrawn at the latest by September 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO/ASTM 52911-3:2023 has been approved by CEN as EN ISO/ASTM 52911-3:2023
without any modification.
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SIST EN ISO/ASTM 52911-3:2023
INTERNATIONAL ISO/ASTM
STANDARD 52911-3
First edition
2023-02
Additive manufacturing — Design —
Part 3:
PBF-EB of metallic materials
Fabrication additive — Conception —
Partie 3: PBF-EB de matériaux métalliques
Reference number
ISO/ASTM 52911-3:2023(E)
© ISO/ASTM International 2023
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SIST EN ISO/ASTM 52911-3:2023
ISO/ASTM 52911-3:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/ASTM International 2023
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. In the United States, such requests should be sent to ASTM International.
ISO copyright office ASTM International
CP 401 • Ch. de Blandonnet 8 100 Barr Harbor Drive, PO Box C700
CH-1214 Vernier, Geneva West Conshohocken, PA 19428-2959, USA
Phone: +41 22 749 01 11 Phone: +610 832 9634
Fax: +610 832 9635
Email: copyright@iso.org Email: khooper@astm.org
Website: www.iso.org Website: www.astm.org
Published in Switzerland
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ISO/ASTM 52911-3:2023(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.2
4.1 Symbols . 2
4.2 Abbreviated terms . 3
5 Characteristics of powder bed fusion (PBF) processes . 3
5.1 General . 3
5.2 Part size and cost considerations . 4
5.3 Benefits to be considered in regard to the PBF process . 4
5.4 Limitations to be considered in regard to the PBF process . 4
5.5 Build layout, part orientation, and cost considerations. 5
5.6 Feature constraints (islands, overhang, stair-step effect) . 6
5.6.1 General . 6
5.6.2 Islands . 6
5.6.3 Overhang . 6
5.6.4 Stair-step effect . 6
5.7 Dimensional, form and positional accuracy . 7
5.8 Data quality, resolution, representation . 7
6 Design guidelines for electron beam powder bed fusion of metals (PBF-EB/M) .8
6.1 General . 8
6.1.1 Selecting PBF-EB/M . 8
6.1.2 Design and test cycles . 8
6.2 Material and structural characteristics . 8
6.3 Build orientation, positioning and arrangement . 9
6.3.1 General . 9
6.3.2 Powder spreading . 9
6.3.3 Support structures design . 10
6.3.4 Part nesting . 12
6.3.5 Build plate part design considerations. 13
6.3.6 Curl effect . 13
6.3.7 Melt parameters . 14
6.4 Anisotropy/heterogeneity of the material and part characteristics .15
6.4.1 General .15
6.4.2 Grain morphology .15
6.4.3 Porosity . . . 16
6.4.4 Intermetallic diffusion layer . 16
6.4.5 Chemistry heterogeneity . 16
6.4.6 Thermal history . 16
6.5 Surfaces . 17
6.6 Post-processing . 17
6.6.1 General . 17
6.6.2 Surface finishing . 17
6.6.3 Removal of powder residue . 17
6.6.4 Removal of support structures. 18
6.6.5 Geometric tolerances. 18
6.6.6 Heat treatment . 18
6.7 Design considerations . 18
6.7.1 General . 18
6.7.2 Cavities . 19
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6.7.3 Gaps . 19
6.7.4 Wall thicknesses . 19
6.7.5 Holes and channels . 19
6.7.6 Integrated markings . 20
6.8 Example applications .20
6.8.1 Topology optimized bracket printed using stacking build layout (provided
by GE Arcam) . 20
6.8.2 Acetabular cup stacking design (provided by LimaCorporate Spa) . 21
6.8.3 Optimized elbow implant design (provided by LimaCorporate Spa) .22
6.8.4 Lightweight pipe design (provided by JEOL) . 23
Bibliography .25
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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 261, Additive manufacturing, in
cooperation with ASTM Committee F42, Additive Manufacturing Technologies, on the basis of a
partnership agreement between ISO and ASTM International with the aim to create a common set of
ISO/ASTM standards on additive manufacturing, and in collaboration with the European Committee for
Standardization (CEN) Technical Committee CEN/TC 438, Additive manufacturing, in accordance with
the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 52911 series can be found on the ISO website.
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.
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Introduction
Powder bed fusion of metals (PBF/M) is an additive manufacturing (AM) process that offers additional
manufacturing options alongside other established AM processes. PBF/M has the potential to reduce
manufacturing time and costs, and increase part functionality. Practitioners are aware of the strengths
and weaknesses of conventional, long-established manufacturing processes, such as cutting, joining and
shaping processes (e.g. by machining, welding or injection moulding), and of giving them appropriate
consideration at the design stage and when selecting the manufacturing process. In the case of PBF/M
and AM in general, design and manufacturing engineers only have a limited pool of experience.
Without the limitations associated with conventional processes, the use of PBF/M offers designers and
manufacturers a high degree of freedom and this requires an understanding about the possibilities and
limitations of the process.
The ISO 52911 series provides guidance for different powder bed fusion (PBF) technologies. In addition
to this document on PBF-EB/M, the series is made up of ISO 52911-1 on laser-based powder bed fusion
of metals (PBF-LB/M) and ISO 52911-2 on laser-based powder bed fusion of polymers (PBF-LB/P). Each
document in the series shares Clauses 1 to 5, where general information including terminology and the
PBF process is provided. The subsequent clauses focus on the specific technology.
This document provides support to technology users, such as design and production engineers, when
designing parts that need to be manufactured by means of PBF-EB/M. It will help practitioners to
explore the benefits of PBF-EB/M and to recognize the process-related limitations when designing
parts. It also builds on ISO/ASTM 52910 to extend the requirements, guidelines and recommendations
for AM design to include the PBF-EB/M process.
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SIST EN ISO/ASTM 52911-3:2023
INTERNATIONAL STANDARD ISO/ASTM 52911-3:2023(E)
Additive manufacturing — Design —
Part 3:
PBF-EB of metallic materials
1 Scope
This document specifies the features of electron beam powder bed fusion of metals (PBF-EB/M) and
provides detailed design recommendations.
Some of the fundamental principles are also applicable to other additive manufacturing (AM) processes,
provided that due consideration is given to process-specific features.
This document also provides a state of the art review of design guidelines associated with the use of
powder bed fusion (PBF) by bringing together relevant knowledge about this process and by extending
the scope of ISO/ASTM 52910.
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/ASTM 52900, Additive manufacturing — General principles — Fundamentals and vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/ASTM 52900 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 https:// www .electropedia .org/
3.1
curl effect
dimensional distortion as the melted material cools and solidifies
after being built or by poorly evacuated heat input
3.2
downskin area
D
(sub-)area where the normal vector n projection on the Z-axis is negative
Note 1 to entry: See Figure 1.
1
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SIST EN ISO/ASTM 52911-3:2023
ISO/ASTM 52911-3:2023(E)
3.3
downskin angle
δ
angle between the plane of the build platform and the downskin area (3.2) where the value lies between
0° (parallel to the build platform) and 90° (perpendicular to the build platform)
Note 1 to entry: See Figure 1.
3.4
upskin area
U
(sub-)area where the normal vector n in relation to Z-axis is positive
Note 1 to entry: See Figure 1.
3.5
upskin angle
υ
angle between the plane of the build platform and the upskin area (3.4) where the value lies between 0°
(parallel to the build platform) and 90° (perpendicular to the build platform)
Note 1 to entry: See Figure 1.
Key
δ downskin angles U upskin (right) areas
normal vector υ upskin angles
n
D downskin (left) areas Z build direction
[3]
NOTE Source: VDI 3405-3:2015 .
Figure 1 — Orientation of the part surfaces relating to the build platform
4 Symbols and abbreviated terms
4.1 Symbols
The symbols given in Table 1 are used in this document.
Table 1 — Symbols
Symbol Designation Unit
a overhang mm
2
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SIST EN ISO/ASTM 52911-3:2023
ISO/ASTM 52911-3:2023(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Symbol Designation Unit
2
D downskin area mm
2
I island mm
n normal vector —
2
U upskin area mm
δ downskin angle °
υ upskin angle °
4.2 Abbreviated terms
The following abbreviated terms are used in this document.
CT computed tomography
DICOM digital imaging and communications in medicine
PBF-EB/M electron beam powder bed fusion of metals
HIP hot isostatic pressing
PBF-LB laser-based powder bed fusion
PBF-LB/M laser-based powder bed fusion of metals (also known as, for example, laser beam melting,
selective laser melting)
PBF-LB/P laser-based powder bed fusion of polymers (also known as, for example, laser beam melting,
selective laser melting)
MRI magnetic resonance imaging
5 Characteristics of powder bed fusion (PBF) processes
5.1 General
Consideration should be given to the specific characteristics of the manufacturing process used in order
to optimize the design of a part. Examples of the features of AM processes which need to be taken into
consideration during the design and process planning stages are listed in 5.2 to 5.8. With regards to
metal processing, a distinction can be made between, for example, laser-based PBF (applied for metals
and polymers) and electron beam-based PBF (applied for metals only).
Polymers PBF uses, in almost every case, low power lasers to sinter polymer powders together. Electron
beam powder bed fusion for polymers is not usually considered because the negative charge from the
electron beam will accumulate in non-conductive polymer powder and cause repulsive events that
will ruin powder layer continuity and make any controlled sintering or melting impossible. As with
polymer powders PBF, metals PBF includes varying processing techniques. Like polymers, metals PBF
often requires the addition of support structures (see 6.3.3). Metals PBF processes may use low-power
lasers to bind powder particles by only melting the surface of the powder particles or high-power
(approximately 200 W to 1 kW) energy beams to fully melt and fuse the powder particles together.
PBF-EB/M and PBF-LB/M have similar capabilities, although differences between these processes
leads, in general, to PBF-EB/M supporting faster build rates at lower feature resolution compared
to PBF-LB/M. The beam energy from the electron beam is of a higher intensity (due to a high energy
source 3 kW to 6 kW), and the mechanism to raster the beam (i.e. electromagnetics for PBF-EB/M,
optics for PBF-LB/M) differs between the two types of PBF processes. PBF-EB/M also tends to utilize a
larger beam spot size, larger powder size distribution, and larger layer thickness. In general, PBF-EB/M
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SIST EN ISO/ASTM 52911-3:2023
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subjects parts to less thermal stresses (as powder layers are preheated before melting) and have faster
build rates, but the trade-off often comes with general greater minimum feature sizes and greater
surface roughness compared to PBF-LB/M.
5.2 Part size and cost considerations
Part size is not only limited by the working area/working volume of the PBF-machine. The occurrence
of cracks and deformation due to residual stresses can also limit the maximum part size. Another
important practical factor that can limit the maximum part size is part cost having a direct relation to
part size.
Part cost can be minimized by choosing part location and build orientation in a way that allows nesting
of as many parts as possible.
Also, powder reuse protocols impact part cost significantly. If no reuse is allowed then all remaining
powder is s
...
SLOVENSKI STANDARD
oSIST prEN ISO/ASTM 52911-3:2022
01-februar-2022
[Not translated]
Additive Manufacturing - Design - Part 3: Electron beam powder bed fusion of metals
(ISO/ASTM 52911-3:2021)
Additive Manufacturing - Konstruktion - Teil 3: Standardrichtlinie für das
pulverbettbasierte Elektronenstrahlschmelzen von Metallen (ISO/ASTM 52911-3:2021)
Fabrication additive - Conception - Partie 3: Fusion par faisceau d'électrons sur lit de
poudre métallique (ISO/ASTM 52911-3:2021)
Ta slovenski standard je istoveten z: prEN ISO/ASTM 52911-3
ICS:
25.030 3D-tiskanje Additive manufacturing
oSIST prEN ISO/ASTM 52911-3:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN ISO/ASTM 52911-3:2022
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oSIST prEN ISO/ASTM 52911-3:2022
DRAFT INTERNATIONAL STANDARD
ISO/ASTM DIS 52911-3
ISO/TC 261 Secretariat: DIN
Voting begins on: Voting terminates on:
2021-12-13 2022-03-07
Additive Manufacturing — Design —
Part 3:
Electron beam powder bed fusion of metals
Fabrication additive - Conception —
Partie 3: Fusion par faisceau d'électrons sur lit de poudre métallique
ICS: 25.030
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/ASTM DIS 52911-3:2021(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO/ASTM International 2021
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oSIST prEN ISO/ASTM 52911-3:2022
ISO/ASTM DIS 52911-3:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/ASTM International 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. In the United States, such requests should be sent to ASTM International.
ISO copyright office ASTM International
CP 401 • Ch. de Blandonnet 8 100 Barr Harbor Drive, PO Box C700
CH-1214 Vernier, Geneva West Conshohocken, PA 19428-2959, USA
Phone: +41 22 749 01 11 Phone: +610 832 9634
Fax: +610 832 9635
Email: copyright@iso.org Email: khooper@astm.org
Website: www.iso.org Website: www.astm.org
Published in Switzerland
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oSIST prEN ISO/ASTM 52911-3:2022
ISO/ASTM DIS 52911-3:2021(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.2
4.1 Symbols . 2
4.2 Abbreviated terms . 3
5 Characteristics of powder bed fusion (PBF) processes . 3
5.1 General . 3
5.2 Size of the parts . 4
5.3 Benefits to be considered in regard to the PBF process . 4
5.4 Limitations to be considered in regard to the PBF process . 4
5.5 Economic and time efficiency . 5
5.6 Feature constraints (islands, overhang, stair-step effect) . 6
5.6.1 General . 6
5.6.2 Islands . 6
5.6.3 Overhang . 6
5.6.4 Stair-step effect . 6
5.7 Dimensional, form and positional accuracy . 7
5.8 Data quality, resolution, representation . 7
6 Design guidelines for electron beam powder bed fusion of metals (PBF-EB/M) .8
6.1 General . 8
6.1.1 Selecting PBF-EB/M . 8
6.1.2 Design and test cycles . 8
6.2 Material and structural characteristics . 8
6.3 Build orientation, positioning and arrangement . 9
6.3.1 General . 9
6.3.2 Powder spreading . 9
6.3.3 Support structures design . 10
6.3.4 Part nesting .12
6.3.5 Build plate part design considerations. 13
6.3.6 Curl effect . 13
6.3.7 Melt parameters . 14
6.4 Anisotropy/heterogeneity of the material and part characteristics .15
6.4.1 General .15
6.4.2 Grain morphology . 15
6.4.3 Porosity . .15
6.4.4 Intermetallic diffusion layer . 16
6.4.5 Chemistry heterogeneity . 16
6.4.6 Thermal history . 16
6.5 Surfaces . 17
6.6 Post-production finishing . 17
6.6.1 General . 17
6.6.2 Surface finishing . 17
6.6.3 Removal of powder residue . 17
6.6.4 Removal of support structures. 17
6.6.5 Geometric tolerances. 18
6.6.6 Heat treatment . 18
6.7 Design considerations . 18
6.7.1 General . 18
6.7.2 Cavities . 18
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6.7.3 Gaps . 19
6.7.4 Wall thicknesses . 19
6.7.5 Holes and channels . 19
6.7.6 Integrated markings . 19
6.8 Example applications .20
6.8.1 Topology Optimized Bracket Printed using Stacking Build Layout
(provided by GE Arcam) . 20
6.8.2 Acetabular cup stacking design (provided by LimaCorporate Spa) . 21
6.8.3 Optimized elbow implant design (provided by LimaCorporate Spa) .23
6.8.4 Lightweight pipe design (provided by JEOL) . 23
Bibliography .25
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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 261, Additive manufacturing, in
cooperation with ASTM Committee F42, Additive Manufacturing Technologies, on the basis of a
partnership agreement between ISO and ASTM International with the aim to create a common set of
ISO/ASTM standards on Additive Manufacturing.
A list of all parts in the ISO 52911 series can be found on the ISO website.
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.
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Introduction
Powder bed fusion of metals (PBF/M) is an additive manufacturing (AM) process that offers additional
manufacturing options alongside other established AM processes. PBF/M has the potential to reduce
manufacturing time and costs, and increase part functionality. Practitioners are aware of the strengths
and weaknesses of conventional, long-established manufacturing processes, such as cutting, joining and
shaping processes (e.g. by machining, welding or injection moulding), and of giving them appropriate
consideration at the design stage and when selecting the manufacturing process. In the case of PBF/M
and AM in general, design and manufacturing engineers only have a limited pool of experience.
Without the limitations associated with conventional processes, the use of PBF/M offers designers and
manufacturers a high degree of freedom and this requires an understanding about the possibilities and
limitations of the process.
The ISO 52911 series provides guidance for different powder bed fusion (PBF) technologies. In addition
to this document on PBF-EB/M, the series is made up of ISO 52911-1 on laser-based powder bed fusion
of metals (PBF-LB/M) and ISO 52911-2 on laser-based powder bed fusion of polymers (PBF-LB/P). Each
document in the series shares Clauses 1 to 5, where general information including terminology and the
PBF process is provided. The subsequent clauses focus on the specific technology.
This document provides support to technology users, such as design and production engineers, when
designing parts that need to be manufactured by means of PBF-EB/M. It will help practitioners to
explore the benefits of PBF-EB/M and to recognize the process-related limitations when designing
parts. It also builds on ISO/ASTM 52910 to extend the requirements, guidelines and recommendations
for AM design to include the PBF process.
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DRAFT INTERNATIONAL STANDARD ISO/ASTM DIS 52911-3:2021(E)
Additive Manufacturing — Design —
Part 3:
Electron beam powder bed fusion of metals
1 Scope
This document specifies the features of electron beam powder bed fusion of metals (PBF-EB/M) and
provides detailed design recommendations.
Some of the fundamental principles are also applicable to other additive manufacturing (AM) processes,
provided that due consideration is given to process-specific features.
This document also provides a state of the art review of design guidelines associated with the use of
powder bed fusion (PBF) by bringing together relevant knowledge about this process and by extending
the scope of ISO/ASTM 52910.
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/ASTM 52900, Additive manufacturing — General principles — Fundamentals and vocabulary
ISO 17296-2, Additive manufacturing — General principles — Part 2: Overview of process categories and
feedstock
ISO/ASTM 52915, Specification for additive manufacturing file format (AMF) Version 1.2
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/ASTM 52900 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1
curl effect
thermal and residual stress effect
dimensional distortion as the melted material cools and solidifies
after being built or by poorly evacuated heat input
3.2
downskin area
D
(sub-)area where the normal vector n projection on the z-axis is negative
Note 1 to entry: See Figure 1.
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3.3
downskin angle
δ
angle between the plane of the build platform and the downskin area (3.2) where the value lies between
0° (parallel to the build platform) and 90° (perpendicular to the build platform)
Note 1 to entry: See Figure 1.
3.4
upskin area
U
(sub-)area where the normal vector n in relation to z-axis is positive
Note 1 to entry: See Figure 1.
3.5
upskin angle
υ
angle between the plane of the build platform and the upskin area (3.4) where the value lies between 0°
(parallel to the build platform) and 90° (perpendicular to the build platform)
Note 1 to entry: See Figure 1.
[1]
Note 2 to entry: Source: VDI 3405 Part 3:2015 .
Key
δ downskin angles U Upskin (right) areas
normal vector υ Upskin angles
n
D downskin (left) areas Z_ build direction
[1]
Note 1 to entry Source: VDI 3405 Part 3:2015 .
Figure 1 — Orientation of the part surfaces relating to the build platform
4 Symbols and abbreviated terms
4.1 Symbols
The symbols given in Table 1 are used in this document.
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Table 1 — Symbols
Symbol Designation Unit
a overhang mm
2
D downskin area mm
2
I island mm
normal vector —
n
2
U upskin area mm
δ downskin angle °
υ upskin angle °
4.2 Abbreviated terms
The following abbreviated terms are used in this document.
CT computed tomography
DICOM digital imaging and communications in medicine
PBF-EB/M electron beam powder bed fusion of metals
HIP hot isostatic pressing
PBF-LB laser-based powder bed fusion
PBF-LB/M laser-based powder bed fusion of metals (also known as, for example, laser beam melting,
selective laser melting)
PBF-LB/P laser-based powder bed fusion of polymers (also known as, for example, laser beam melting,
selective laser melting)
MRI magnetic resonance imaging
5 Characteristics of powder bed fusion (PBF) processes
5.1 General
Consideration should be given to the specific characteristics of the manufacturing process used in order
to optimize the design of a part. Examples of the features of AM processes which need to be taken into
consideration during the design and process planning stages are listed in 5.2 to 5.8. With regards to
metal processing, a distinction can be made between, for example, laser-based PBF (applied for metals
and polymers) and electron beam-based PBF (applied for metals only).
Polymers PBF uses, in almost every case, low power lasers to sinter polymer powders together. Electron
beam powder bed fusion for polymers is not usually considered because the negative charge from the
electron beam will accumulate in non-conductive polymer powder and cause repulsive events that
will ruin powder layer continuity and make any controlled sintering or melting impossible. As with
polymer powders PBF, metals PBF includes varying processing techniques. Like polymers, metals PBF
often requires the addition of support structures (see 6.3.3). Metals PBF processes may use low-power
lasers to bind powder particles by only melting the surface of the powder particles or high-power
(approximately 200 W to 1 kW) energy beams to fully melt and fuse the powder particles together.
PBF-EB/M and PBF-LB/M have similar capabilities, although differences between these processes leads,
in general, to PBF-EB/M supporting faster build rates at lower feature resolution compared to PBF-
LB/M. The beam energy from the electron beam is of a higher intensity (due to a high energy source
3 to 6 kW), and the mechanism to raster the beam (i.e. electromagnetics for PBF-EB/M, optics for PBF-
LB/M) differs between the two types of PBF processes. PBF-EB/M also tends to utilize a larger beam
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spot size, larger powder size distribution, and larger layer thickness. In general, PBF-EB/M subjects
parts to less thermal stresses (as powder layers are preheated before melting) and have faster build
rates, but the trade-off often comes with general greater minimum feature sizes and greater surface
roughness compared to PBF-LB/M.
5.2 Size of the parts
The size of the parts is not only limited by the working area/working volume of the PBF-machine.
Also, the occurrence of cracks and deformation due to residual stresses can limit the maximal part
size. Another important practical factor that can limit the maximal part size is the cost of production
having a direct relation to the size and volume of the part. Cost of production can be minimized by
choosing part location and build orientation in a way that allows nesting of as many parts as possible.
Also, the volume of powder needed to fill the bed to required volume (part depth x bed area) may be
a consideration. Powder reuse protocols impact this cost significantly. If no reuse is allowed then all
powder is scrapped regardless of volume solidified.
5.3 Benefits to be considered in regard to the PBF process
PBF processes can be advantageous for manufacturing parts where the following points are relevant.
— Integration of multiple functions in the same part
— Parts can be manufactured to near-net shape (i.e. close to the finished shape and size).
— Degrees of design freedom for parts are typically higher. Limitations of conventional manufacturing
processes do not usually exist, e.g. for
— tool accessibility, and
— machining undercuts.
— A wide range of complex geometries can be produced, such as
— free-form geometries, e.g. organic structures,
— topologically optimised structures, in order to reduce mass and optimize mechanical properties,
— infill structures, e.g. honeycomb, and
— porous lattice structure on surface of otherwise solid component, e.g. osteosynthesis structures
in medical device industry.
— The degree of part complexity is largely unrelated to production costs, unlike most conventional
manufacturing.
— Assembly and joining processes can be reduced through part consolidation, potentially achieving
en bloc construction.
— Overall part characteristics can be selectively configured by adjusting process parameters locally.
— Reduction in lead times from design to part production.
5.4 Limitations to be considered in regard to the PBF process
Certain disadvantages typically associated with AM processes should be taken into consideration
during product design.
— Shrinkage, residual stress and deformation can occur due to temperature differences. Preheating
of the powder bed (which is the normal procedure in PBF-EB/M) can be used to minimize these
effects.
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— The surface quality of AM parts is typically influenced by the layer-wise build-up technique (stair-
step effect) and utilized powder size distribution. Post-processing may be required, depending on
the application.
— Consideration should be given to deviations from form, dimensional and positional tolerances of
parts. A machining allowance should therefore be provided for post-production finishing. Specified
geometric tolerances can be achieved by precision post-processing operations.
— Anisotropic characteristics typically arise due to the layer-wise build-up and should be taken into
account during process planning.
— Not all materials available for conventional processes are currently suitable for PBF processes.
— Material properties can differ from expected values known from other technologies like forging and
casting. Material properties can be influenced significantly due to process settings and control.
— Excessive use and/or over-reliance on support structures can lead to both high material waste and
increased risk of build failure.
— Unmelted powder removal after processing is necessary, and for PBF-EB/M this powder is often
lig
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