SIST EN ISO/ASTM 52911-2:2020
(Main)Additive manufacturing - Design - Part 2: Laser-based powder bed fusion of polymers (ISO/ASTM 52911-2:2019)
Additive manufacturing - Design - Part 2: Laser-based powder bed fusion of polymers (ISO/ASTM 52911-2:2019)
This standard aims to give design and production engineers a working basis which enables them to have informed consideration about the use of Laser-based Powder Bed Fusion of Polymers. This standard describes the features of Laser-based Powder Bed Fusion of Polymers and provides detailed design recommendations. Some of the fundamental principles can also be applied to other AM processes, provided that due considerations are given to the processspecific features. The purpose of this standard is to help practitioners explore the benefits of Laser-based Powder Bed Fusion of Polymers and recognising the process-related limitations when designing parts. The document also provides a state of the art review of design guidelines associated with the use of Powder Bed Fusion by bringing together relevant knowledge about this process and to extend the scope of ISO/ASTM 52910 “Standard Practice/Guide for Design for Additive Manufacturing.
Additive Fertigung - Technische Konstruktionsrichtlinie für Pulverbettfusion - Teil 2: Laserbasierte Pulverbettfusion von Polymeren (ISO/ASTM 52911-2:2019)
Dieses Dokument legt die Merkmale der laserbasierten Pulverbettfusion von Polymeren (LB PBF P) fest und bietet detaillierte Konstruktionsempfehlungen.
Einige der grundlegenden Prinzipien gelten auch für andere additive Fertigungsverfahren (AM Verfahren), 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 2: Fusion laser sur lit de poudre polymère (ISO/ASTM 52911-2:2019)
Le présent document spécifie les caractéristiques de la fusion laser sur lit de poudre polymère (LB-PBF/P) et fournit des recommandations détaillées de conception.
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 - 2. del: Selektivno lasersko sintranje polimerov (ISO/ASTM 52911-2:2019)
Ta standard podaja priporočila za izbiro materiala, zahteve za proizvodnjo in izdelavo, preskušanje in kvalifikacijo jeklenih struktur ter sestavnih delov za obrate za predelavo nafte in zemeljskega plina na morju in kopnem, ki delujejo v arktičnem okolju ter drugih hladnih okoljih. Ta dokument se uporablja kot dodatek k obstoječim standardom za jeklene strukture, za katere določeni obratovalni pogoji na arktičnem območju niso zadovoljivo obravnavani. Ta dokument podaja določene zahteve, ki zagotavljajo varno delovanje v zvezi z nevarnostjo lomov pri nizkih temperaturah. Te zahteve vplivajo na izbiro kakovostnega razreda materiala in razreda načrtovanja ter na tehnične dobavne pogoje za jeklo. Prav tako vplivajo na zahteve glede izdelave ter preskušanja in kvalifikacije. V tem dokumentu so tudi podana priporočila: – za ublažitev operacijskih in integracijskih vidikov, povezanih s kopičenjem snega in ledu na palubnih konstrukcijah; – za upoštevanje določenih obratovalnih pogojev v arktičnem območju pri ocenjevanju korozije in zahtev za korozijske zaščitne sisteme; – za določene obratovalne zahteve, ki zagotavljajo varno obratovanje v arktičnih območjih. Zahteve v tem dokumentu se uporabljajo pri vseh obratovalnih temperaturah, vendar posamezne zahteve, ki so povezane z zmanjšano zmogljivostjo (izguba moči) pri visokih temperaturah, niso obravnavane. Obstajajo lahko omejitve za ustrezne najnižje načrtovane temperature, ki jih povzroči zmožnost učinkovitosti materiala pri nizki temperaturi, vendar te omejitve ne predstavljajo omejitev za področje uporabe tega dokumenta. Za namene praktične uporabe tega dokumenta so nizke temperature opredeljene kot najnižje pričakovane temperature med obratovanjem (LAST) pod –10 °C.
General Information
Buy Standard
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO/ASTM 52911-2:2020
01-januar-2020
Aditivna proizvodnja - Konstruiranje - 2. del: Selektivno lasersko sintranje
polimerov (ISO/ASTM 52911-2:2019)
Additive manufacturing - Design - Part 2: Laser-based powder bed fusion of polymers
(ISO/ASTM 52911-2:2019)
Additive Fertigung - Technische Konstruktionsrichtlinie für Pulverbettfusion - Teil 2:
Laserbasierte Pulverbettfusion von Polymeren (ISO/ASTM 52911-2:2019)
Fabrication additive - Conception - Partie 2: Fusion laser sur lit de poudre polymère
(ISO/ASTM 52911-2:2019)
Ta slovenski standard je istoveten z: EN ISO/ASTM 52911-2:2019
ICS:
25.030 3D-tiskanje Additive manufacturing
SIST EN ISO/ASTM 52911-2:2020 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 52911-2:2020
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SIST EN ISO/ASTM 52911-2:2020
EN ISO/ASTM 52911-2
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2019
EUROPÄISCHE NORM
ICS 25.030
English Version
Additive manufacturing - Design - Part 2: Laser-based
powder bed fusion of polymers (ISO/ASTM 52911-2:2019)
Fabrication additive - Conception - Partie 2: Fusion Additive Fertigung - Konstruktion - Teil 2:
laser sur lit de poudre polymère (ISO/ASTM 52911- Laserbasierte Pulverbettfusion von Polymeren
2:2019) (ISO/ASTM 52911-2:2019)
This European Standard was approved by CEN on 8 September 2019.
This European Standard was corrected and reissued by the CEN-CENELEC Management Centre on 6 November 2019.
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, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N
EUROPÄISCHES KOMITEE FÜR NORMUN G
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO/ASTM 52911-2:2019 E
worldwide for CEN national Members.
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EN ISO/ASTM 52911-2:2019 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO/ASTM 52911-2:2020
EN ISO/ASTM 52911-2:2019 (E)
European foreword
This document (EN ISO/ASTM 52911-2:2019) 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 April 2020, and conflicting national standards shall be
withdrawn at the latest by April 2020.
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.
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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO/ASTM 52911-2:2019 has been approved by CEN as EN ISO/ASTM 52911-2:2019
without any modification.
3
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SIST EN ISO/ASTM 52911-2:2020
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SIST EN ISO/ASTM 52911-2:2020
INTERNATIONAL ISO/ASTM
STANDARD 52911-2
First edition
2019-09
Additive manufacturing — Design —
Part 2:
Laser-based powder bed fusion of
polymers
Fabrication additive — Conception —
Partie 2: Fusion laser sur lit de poudre polymère
Reference number
ISO/ASTM 52911-2:2019(E)
©
ISO/ASTM International 2019
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SIST EN ISO/ASTM 52911-2:2020
ISO/ASTM 52911-2:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/ASTM International 2019
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: +41 22 749 09 47 Fax: +610 832 9635
Email: copyright@iso.org Email: khooper@astm.org
Website: www.iso.org Website: www.astm.org
Published in Switzerland
ii © ISO/ASTM International 2019 – All rights reserved
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ISO/ASTM 52911-2:2019(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 . 3
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) . 5
5.6.1 General. 5
5.6.2 Islands . 5
5.6.3 Overhang . 6
5.6.4 Stair-step effect . 6
5.7 Dimensional, form and positional accuracy . 6
5.8 Data quality, resolution, representation . 6
6 Design guidelines for laser-based powder bed fusion of polymers (LB-PBF/P) .7
6.1 General . 7
6.2 Material and structural characteristics . 7
6.3 Anisotropy of the material characteristics. 8
6.4 Build orientation, positioning and arrangement . 9
6.4.1 General. 9
6.4.2 Powder coating . 9
6.4.3 Part location in the build chamber . 9
6.4.4 Oversintering . 9
6.4.5 Packing parts efficiently in the build chamber . 9
6.5 Surface roughness .10
6.6 Post-production finishing .10
6.7 Design considerations.11
6.7.1 Allowing for powder removal .11
6.7.2 Reducing warpage .11
6.7.3 Wall thickness .11
6.7.4 Gaps, cylinders and holes .11
6.7.5 Lattice structures .12
6.7.6 Fluid channels .12
6.7.7 Springs and elastic elements .13
6.7.8 Connecting elements and fasteners.13
6.7.9 Static assemblies .14
6.7.10 Movable assemblies .15
6.7.11 Bearings .15
6.7.12 Joints .15
6.7.13 Integrated markings .16
6.7.14 Cutting and joining .16
6.8 Example applications .17
6.8.1 Functional toy car with integrated spring .17
6.8.2 Robot gripper .18
7 General design consideration .19
© ISO/ASTM International 2019 – All rights reserved iii
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Bibliography .20
iv © ISO/ASTM International 2019 – All rights reserved
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ISO/ASTM 52911-2:2019(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 261, Additive manufacturing, in
cooperation with ASTM 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.
© ISO/ASTM International 2019 – All rights reserved v
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Introduction
Laser-based powder bed fusion of polymers (LB-PBF/P) describes an additive manufacturing (AM)
process and offers an additional manufacturing option alongside established processes. LB-PBF/P 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 LB-PBF/P 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 LB-PBF/P 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. It is
intended that the series will include ISO 52911-1 on laser-based powder bed fusion of metals (LB-
1)
PBF/M), this document on LB-PBF/P, and ISO 52911-3 on electron beam powder bed fusion of metals
(EB-PBF/M). Clauses 1 to 5, where general information including terminology and the PBF process is
provided, are similar throughout the series. The subsequent clauses focus on the specific technology.
[8]
This document is based on VDI 3405-3:2015 . It provides support to technology users, such as design
and production engineers, when designing parts that need to be manufactured by means of LB-PBF/P.
It will help practitioners to explore the benefits of LB-PBF/P and to recognize the process-related
[4]
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.
1) Under preparation.
vi © ISO/ASTM International 2019 – All rights reserved
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SIST EN ISO/ASTM 52911-2:2020
INTERNATIONAL STANDARD ISO/ASTM 52911-2:2019(E)
Additive manufacturing — Design —
Part 2:
Laser-based powder bed fusion of polymers
1 Scope
This document specifies the features of laser-based powder bed fusion of polymers (LB-PBF/P) 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 http: //www .electropedia .org/
3.1
downskin area
D
(sub-)area where the normal vector n projection on the z-axis is negative
Note 1 to entry: See Figure 1.
3.2
downskin angle
δ
angle between the plane of the build platform and the downskin area (3.1)
Note 1 to entry: The angle lies between 0° (parallel to the build platform) and 90° (perpendicular to the build
platform).
Note 2 to entry: See Figure 1.
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SIST EN ISO/ASTM 52911-2:2020
ISO/ASTM 52911-2:2019(E)
3.3
upskin area
U
(sub-)area where the normal vector n projection on the z-axis is positive
Note 1 to entry: See Figure 1.
3.4
upskin angle
υ
angle between the build platform plane and the upskin area (3.3)
Note 1 to entry: The angle lies between 0° (parallel to the build platform) and 90° (perpendicular to the build
platform).
Note 2 to entry: See Figure 1.
Key
z build direction
SOURCE VDI 3405-3:2015.
Figure 1 — Upskin and downskin areas U and D, upskin and downskin angles υ and δ, normal
vector n
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
D downskin area mm
2
I island mm
normal vector —
n
3
P part mm
2 © ISO/ASTM International 2019 – All rights reserved
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SIST EN ISO/ASTM 52911-2:2020
ISO/ASTM 52911-2:2019(E)
Table 1 (continued)
Symbol Designation Unit
Ra mean roughness µm
Rz average surface roughness µm
2
U upskin area mm
δ downskin angle °
υ upskin angle °
4.2 Abbreviated terms
The following abbreviated terms are used in this document.
AM additive manufacturing
AMF additive manufacturing file format
CT computed tomography
DICOM digital imaging and communications in medicine
CAD computer aided design
EB-PBF/M electron beam powder bed fusion of metals
LB-PBF laser-based powder bed fusion
LB-PBF/M laser-based powder bed fusion of metals (also known as e.g. laser beam melting, selective
laser melting)
LB-PBF/P laser-based powder bed fusion of polymers (also known as e.g. laser beam melting,
selective laser melting)
MRI magnetic resonance imaging
PBF powder bed fusion
STL stereolithography format or surface tessellation language
3MF 3D manufacturing format
5 Characteristics of powder bed fusion (PBF) processes
5.1 General
Consideration shall 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.
5.2 Size of the parts
The size of the parts is limited by the working area/working volume of the PBF-machine. Also, the
occurrence of cracks and deformation due to residual stresses limits the maximum part size. Another
important practical factor that limits the maximum 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 cost
of powder needed to fill the bed to the required volume (part depth × bed area) may be a consideration.
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SIST EN ISO/ASTM 52911-2:2020
ISO/ASTM 52911-2:2019(E)
Powder reuse rules impact this cost significantly. If no reuse is allowed, then all powder is scrapped
regardless of solidified volume.
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:
— Parts can be manufactured to near-net shape (i.e. close to the finished shape and size), without
further post processing tools, in a single process step.
— Degrees of design freedom for parts are typically high. Limitations of conventional manufacturing
processes do not usually exist, e.g. for:
— tool accessibility, and
— undercuts.
— A wide range of complex geometries can be produced, such as:
[17]
— free-form geometries, e.g. organic structures ,
— topologically optimized structures,
— infill structures, e.g. honeycomb, sandwich and mesh structures.
— The degree of part complexity is largely unrelated to production costs.
— Assembly and joining processes can be reduced through single-body construction.
— Overall part characteristics can be selectively configured by adjusting process parameters locally.
— Reduction in lead times until part production.
5.4 Limitations to be considered in regard to the PBF process
Certain disadvantages typically associated with AM processes shall be taken into consideration during
product design.
— Shrinkage, residual stress and deformation can occur due to local temperature differences.
— The surface quality of AM parts is typically influenced by the layer-wise build-up technique (stair-
step effect). Post-processing can be required, depending on the application.
— Consideration shall be given to deviations from form, dimensional and positional tolerances of
parts. A machining allowance shall therefore be provided for post-production finishing. Specified
geometric tolerances can be achieved by precision post-processing.
— Anisotropic characteristics typically arise due to the layer-wise build-up and shall 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 injection
moulding and casting. Material properties can be influenced significantly by process settings and
control.
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5.5 Economic and time efficiency
Provided that the geometry permits a part to be placed in the build space in such a way that it can be
manufactured as cost-effectively as possible, various different criteria for optimization are available
depending on the number of units planned.
— In the case of a one-off production, height is the factor that has the greatest impact on build costs.
Parts shall be oriented in such a way that the build height is kept to a minimum, provided that the
geometry permits such an orientation.
— If the intention is to manufacture a larger number of units, then the build space shall be used as
efficiently as possible. Provided that the part geometry permits such orientation, strategies for
reorientation and nesting shall be utilized to maximize the available build space.
— The powder that remains in the system after a build can be reused in some cases. Reuse depends
on the application, material, and specific requirements. Powder changes can be inefficient and
time consuming. Although they are necessary when changing material type, powd
...
SLOVENSKI STANDARD
SIST EN ISO/ASTM 52911-2:2020
01-januar-2020
Aditivna proizvodnja - Načrtovanje - 2. del: Laserska fuzija polimernih prahastih
plasti (ISO/ASTM 52911-2:2019)
Additive manufacturing - Design - Part 2: Laser-based powder bed fusion of polymers
(ISO/ASTM 52911-2:2019)
Additive Fertigung - Technische Konstruktionsrichtlinie für Pulverbettfusion - Teil 2:
Laserbasierte Pulverbettfusion von Polymeren (ISO/ASTM 52911-2:2019)
Fabrication additive - Conception - Partie 2: Fusion laser sur lit de poudre polymère
(ISO/ASTM 52911-2:2019)
Ta slovenski standard je istoveten z: EN ISO/ASTM 52911-2:2019
ICS:
25.030 3D-tiskanje Additive manufacturing
SIST EN ISO/ASTM 52911-2:2020 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 52911-2:2020
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SIST EN ISO/ASTM 52911-2:2020
EN ISO/ASTM 52911-2
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2019
EUROPÄISCHE NORM
ICS 25.030
English Version
Additive manufacturing - Design - Part 2: Laser-based
powder bed fusion of polymers (ISO/ASTM 52911-2:2019)
Fabrication additive - Conception - Partie 2: Fusion Additive Fertigung - Konstruktion - Teil 2:
laser sur lit de poudre polymère (ISO/ASTM 52911- Laserbasierte Pulverbettfusion von Polymeren
2:2019) (ISO/ASTM 52911-2:2019)
This European Standard was approved by CEN on 8 September 2019.
This European Standard was corrected and reissued by the CEN-CENELEC Management Centre on 6 November 2019.
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, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N
EUROPÄISCHES KOMITEE FÜR NORMUN G
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO/ASTM 52911-2:2019 E
worldwide for CEN national Members.
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EN ISO/ASTM 52911-2:2019 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO/ASTM 52911-2:2020
EN ISO/ASTM 52911-2:2019 (E)
European foreword
This document (EN ISO/ASTM 52911-2:2019) 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 April 2020, and conflicting national standards shall be
withdrawn at the latest by April 2020.
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.
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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO/ASTM 52911-2:2019 has been approved by CEN as EN ISO/ASTM 52911-2:2019
without any modification.
3
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SIST EN ISO/ASTM 52911-2:2020
INTERNATIONAL ISO/ASTM
STANDARD 52911-2
First edition
2019-09
Additive manufacturing — Design —
Part 2:
Laser-based powder bed fusion of
polymers
Fabrication additive — Conception —
Partie 2: Fusion laser sur lit de poudre polymère
Reference number
ISO/ASTM 52911-2:2019(E)
©
ISO/ASTM International 2019
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SIST EN ISO/ASTM 52911-2:2020
ISO/ASTM 52911-2:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/ASTM International 2019
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: +41 22 749 09 47 Fax: +610 832 9635
Email: copyright@iso.org Email: khooper@astm.org
Website: www.iso.org Website: www.astm.org
Published in Switzerland
ii © ISO/ASTM International 2019 – All rights reserved
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ISO/ASTM 52911-2:2019(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 . 3
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) . 5
5.6.1 General. 5
5.6.2 Islands . 5
5.6.3 Overhang . 6
5.6.4 Stair-step effect . 6
5.7 Dimensional, form and positional accuracy . 6
5.8 Data quality, resolution, representation . 6
6 Design guidelines for laser-based powder bed fusion of polymers (LB-PBF/P) .7
6.1 General . 7
6.2 Material and structural characteristics . 7
6.3 Anisotropy of the material characteristics. 8
6.4 Build orientation, positioning and arrangement . 9
6.4.1 General. 9
6.4.2 Powder coating . 9
6.4.3 Part location in the build chamber . 9
6.4.4 Oversintering . 9
6.4.5 Packing parts efficiently in the build chamber . 9
6.5 Surface roughness .10
6.6 Post-production finishing .10
6.7 Design considerations.11
6.7.1 Allowing for powder removal .11
6.7.2 Reducing warpage .11
6.7.3 Wall thickness .11
6.7.4 Gaps, cylinders and holes .11
6.7.5 Lattice structures .12
6.7.6 Fluid channels .12
6.7.7 Springs and elastic elements .13
6.7.8 Connecting elements and fasteners.13
6.7.9 Static assemblies .14
6.7.10 Movable assemblies .15
6.7.11 Bearings .15
6.7.12 Joints .15
6.7.13 Integrated markings .16
6.7.14 Cutting and joining .16
6.8 Example applications .17
6.8.1 Functional toy car with integrated spring .17
6.8.2 Robot gripper .18
7 General design consideration .19
© ISO/ASTM International 2019 – All rights reserved iii
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Bibliography .20
iv © ISO/ASTM International 2019 – All rights reserved
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ISO/ASTM 52911-2:2019(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 261, Additive manufacturing, in
cooperation with ASTM 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.
© ISO/ASTM International 2019 – All rights reserved v
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Introduction
Laser-based powder bed fusion of polymers (LB-PBF/P) describes an additive manufacturing (AM)
process and offers an additional manufacturing option alongside established processes. LB-PBF/P 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 LB-PBF/P 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 LB-PBF/P 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. It is
intended that the series will include ISO 52911-1 on laser-based powder bed fusion of metals (LB-
1)
PBF/M), this document on LB-PBF/P, and ISO 52911-3 on electron beam powder bed fusion of metals
(EB-PBF/M). Clauses 1 to 5, where general information including terminology and the PBF process is
provided, are similar throughout the series. The subsequent clauses focus on the specific technology.
[8]
This document is based on VDI 3405-3:2015 . It provides support to technology users, such as design
and production engineers, when designing parts that need to be manufactured by means of LB-PBF/P.
It will help practitioners to explore the benefits of LB-PBF/P and to recognize the process-related
[4]
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.
1) Under preparation.
vi © ISO/ASTM International 2019 – All rights reserved
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INTERNATIONAL STANDARD ISO/ASTM 52911-2:2019(E)
Additive manufacturing — Design —
Part 2:
Laser-based powder bed fusion of polymers
1 Scope
This document specifies the features of laser-based powder bed fusion of polymers (LB-PBF/P) 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 http: //www .electropedia .org/
3.1
downskin area
D
(sub-)area where the normal vector n projection on the z-axis is negative
Note 1 to entry: See Figure 1.
3.2
downskin angle
δ
angle between the plane of the build platform and the downskin area (3.1)
Note 1 to entry: The angle lies between 0° (parallel to the build platform) and 90° (perpendicular to the build
platform).
Note 2 to entry: See Figure 1.
© ISO/ASTM International 2019 – All rights reserved 1
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SIST EN ISO/ASTM 52911-2:2020
ISO/ASTM 52911-2:2019(E)
3.3
upskin area
U
(sub-)area where the normal vector n projection on the z-axis is positive
Note 1 to entry: See Figure 1.
3.4
upskin angle
υ
angle between the build platform plane and the upskin area (3.3)
Note 1 to entry: The angle lies between 0° (parallel to the build platform) and 90° (perpendicular to the build
platform).
Note 2 to entry: See Figure 1.
Key
z build direction
SOURCE VDI 3405-3:2015.
Figure 1 — Upskin and downskin areas U and D, upskin and downskin angles υ and δ, normal
vector n
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
D downskin area mm
2
I island mm
normal vector —
n
3
P part mm
2 © ISO/ASTM International 2019 – All rights reserved
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SIST EN ISO/ASTM 52911-2:2020
ISO/ASTM 52911-2:2019(E)
Table 1 (continued)
Symbol Designation Unit
Ra mean roughness µm
Rz average surface roughness µm
2
U upskin area mm
δ downskin angle °
υ upskin angle °
4.2 Abbreviated terms
The following abbreviated terms are used in this document.
AM additive manufacturing
AMF additive manufacturing file format
CT computed tomography
DICOM digital imaging and communications in medicine
CAD computer aided design
EB-PBF/M electron beam powder bed fusion of metals
LB-PBF laser-based powder bed fusion
LB-PBF/M laser-based powder bed fusion of metals (also known as e.g. laser beam melting, selective
laser melting)
LB-PBF/P laser-based powder bed fusion of polymers (also known as e.g. laser beam melting,
selective laser melting)
MRI magnetic resonance imaging
PBF powder bed fusion
STL stereolithography format or surface tessellation language
3MF 3D manufacturing format
5 Characteristics of powder bed fusion (PBF) processes
5.1 General
Consideration shall 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.
5.2 Size of the parts
The size of the parts is limited by the working area/working volume of the PBF-machine. Also, the
occurrence of cracks and deformation due to residual stresses limits the maximum part size. Another
important practical factor that limits the maximum 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 cost
of powder needed to fill the bed to the required volume (part depth × bed area) may be a consideration.
© ISO/ASTM International 2019 – All rights reserved 3
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SIST EN ISO/ASTM 52911-2:2020
ISO/ASTM 52911-2:2019(E)
Powder reuse rules impact this cost significantly. If no reuse is allowed, then all powder is scrapped
regardless of solidified volume.
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:
— Parts can be manufactured to near-net shape (i.e. close to the finished shape and size), without
further post processing tools, in a single process step.
— Degrees of design freedom for parts are typically high. Limitations of conventional manufacturing
processes do not usually exist, e.g. for:
— tool accessibility, and
— undercuts.
— A wide range of complex geometries can be produced, such as:
[17]
— free-form geometries, e.g. organic structures ,
— topologically optimized structures,
— infill structures, e.g. honeycomb, sandwich and mesh structures.
— The degree of part complexity is largely unrelated to production costs.
— Assembly and joining processes can be reduced through single-body construction.
— Overall part characteristics can be selectively configured by adjusting process parameters locally.
— Reduction in lead times until part production.
5.4 Limitations to be considered in regard to the PBF process
Certain disadvantages typically associated with AM processes shall be taken into consideration during
product design.
— Shrinkage, residual stress and deformation can occur due to local temperature differences.
— The surface quality of AM parts is typically influenced by the layer-wise build-up technique (stair-
step effect). Post-processing can be required, depending on the application.
— Consideration shall be given to deviations from form, dimensional and positional tolerances of
parts. A machining allowance shall therefore be provided for post-production finishing. Specified
geometric tolerances can be achieved by precision post-processing.
— Anisotropic characteristics typically arise due to the layer-wise build-up and shall 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 injection
moulding and casting. Material properties can be influenced significantly by process settings and
control.
4 © ISO/ASTM International 2019 – All rights reserved
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5.5 Economic and time efficiency
Provided that the geometry permits a part to be placed in the build space in such a way that it can be
manufactured as cost-effectively as possible, various different criteria for optimization are available
depending on the number of units planned.
— In the case of a one-off production, height is the factor that has the greatest impact on build costs.
Parts shall be oriented in such a way that the build height is kept to a minimum, provided that the
geometry permits such an orientation.
— If the intention is to manufacture a larger number of units, then the build space shall be used as
efficiently as possible. Provided that the part geometry permits such orientation, strategies for
reorientation and nesting shall be utilized to maximize the available build space.
— The powder that remains in the system after a build can be reused in some cases. Reuse depends
on the application, material, and specific requirements. Powder changes can be inefficient and
time consuming. Although they are necessary when changing material type, po
...
SLOVENSKI STANDARD
oSIST prEN ISO/ASTM 52911-2:2018
01-februar-2018
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Additive manufacturing - Technical Design Guideline for Powder Bed Fusion - Part 2:
Laser-based Powder Bed Fusion of Polymers (ISO/ASTM DIS 52911-2:2017)
Additive Fertigung - Technische Konstruktionsrichtlinie für Pulverbettfusion - Teil 2:
Laserbasierte Pulverbettfusion von Polymeren (ISO/ASTM DIS 52911-2:2017)
Fabrication additive - Lignes directrices techniques de conception pour la fusion sur lit de
poudre - Partie 2: Fusion laser sur lit de poudre polymère (ISO/ASTM DIS 52911-2:2017)
Ta slovenski standard je istoveten z: prEN ISO/ASTM 52911-2
ICS:
25.030 3D-tiskanje Additive manufacturing
oSIST prEN ISO/ASTM 52911-2:2018 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 52911-2:2018
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oSIST prEN ISO/ASTM 52911-2:2018
DRAFT INTERNATIONAL STANDARD
ISO/ASTM DIS 52911-2
ISO/TC 261 Secretariat: DIN
Voting begins on: Voting terminates on:
2017-11-14 2018-02-06
Additive manufacturing — Technical design guideline for
powder bed fusion —
Part 2:
Laser-based powder bed fusion of polymers
Titre manque —
Partie 2: Titre manque
ICS: 25.030
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
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 52911-2:2017(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 2017
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oSIST prEN ISO/ASTM 52911-2:2018
ISO/ASTM DIS 52911-2:2017(E) ISO/DIS 52911-2:2017(E)
Contents Page
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviations . 3
4.1 Symbols . 3
4.2 Abbreviations . 3
5 Characteristics of Powder Bed Fusion Processes. 4
5.1 General . 4
5.2 Size of the Parts . 4
5.3 Typical Advantages of the PBF process . 4
5.4 Typical Disadvantages of the PBF Process . 5
5.5 Economic and Time Efficiency . 5
5.6 Feature Constraints (Islands, Overhang, Stair-st ep 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 Laser-based Powder Bed Fusion of Polymers (LB-PBF-P) . 8
6.1 General . 8
6.2 Material and Structural Characteristics . 8
6.3 Anisotropy of the Material Characteristics . 9
6.4 Build Orientation, Positioning and Arrangement . 10
6.4.1 General . 10
6.4.2 Powder Coating . 10
6.4.3 Part Location in the Build Chamber . 10
6.4.4 Oversintering . 10
6.4.5 Packing Parts Efficiently in the Build Chamber . 10
6.5 Surface Roughness . 11
6.6 Post-production Finishing . 11
6.7 Design Considerations . 12
6.7.1 Allowing for Powder Removal . 12
COPYRIGHT PROTECTED DOCUMENT
6.7.2 Reducing Warpage . 12
6.7.3 Wall Thickness . 13
© ISO/ASTM International 2017, Published in Switzerland
6.7.4 Gaps, cylinders, and Holes . 13
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
6.7.5 Lattice Structures . 13
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
6.7.6 Fluid Channels . 13
the requester. In the United States, such requests should be sent to ASTM International.
6.7.7 Springs and Elastic Elements . 14
ISO copyright office ASTM International
6.7.8 Connecting Elements and Fasteners . 15
Ch. de Blandonnet 8 • CP 401 100 Barr Harbor Drive, PO Box C700
CH-1214 Vernier, Geneva, Switzerland West Conshohocken, PA 19428-2959, USA
6.7.9 Static Assemblies . 16
Tel. +41 22 749 01 11 Tel. +610 832 9634
6.7.10 Movable Assemblies . 16
Fax +41 22 749 09 47 Fax +610 832 9635
copyright@iso.org khooper@astm.org
www.iso.org www.astm.org
© ISO 2017 – All rights reserved
iii
ii © ISO/ASTM International 2017 – All rights reserved
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oSIST prEN ISO/ASTM 52911-2:2018
ISO/DIS 52911-2:2017(E)
Contents Page
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviations . 3
4.1 Symbols . 3
4.2 Abbreviations . 3
5 Characteristics of Powder Bed Fusion Processes. 4
5.1 General . 4
5.2 Size of the Parts . 4
5.3 Typical Advantages of the PBF process . 4
5.4 Typical Disadvantages of the PBF Process . 5
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 Laser-based Powder Bed Fusion of Polymers (LB-PBF-P) . 8
6.1 General . 8
6.2 Material and Structural Characteristics . 8
6.3 Anisotropy of the Material Characteristics . 9
6.4 Build Orientation, Positioning and Arrangement . 10
6.4.1 General . 10
6.4.2 Powder Coating . 10
6.4.3 Part Location in the Build Chamber . 10
6.4.4 Oversintering . 10
6.4.5 Packing Parts Efficiently in the Build Chamber . 10
6.5 Surface Roughness . 11
6.6 Post-production Finishing . 11
6.7 Design Considerations . 12
6.7.1 Allowing for Powder Removal . 12
6.7.2 Reducing Warpage . 12
6.7.3 Wall Thickness . 13
6.7.4 Gaps, cylinders, and Holes . 13
6.7.5 Lattice Structures . 13
6.7.6 Fluid Channels . 13
6.7.7 Springs and Elastic Elements . 14
6.7.8 Connecting Elements and Fasteners . 15
6.7.9 Static Assemblies . 16
6.7.10 Movable Assemblies . 16
© ISO 2017 – All rights reserved
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ISO/DIS 52911-2:2017(E)
6.7.11 Bearings . 16
6.7.12 Joints . 17
6.7.13 Integrated Markings . 17
6.7.14 Cutting and Joining . 18
6.8 Example application . 18
6.8.1 Functional Toy Car with Integrated Spring . 18
6.8.2 Robot Gripper . 19
7 Conclusions . 21
Bibliography . 22
© ISO 2017 – All rights reserved
iv
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oSIST prEN ISO/ASTM 52911-2:2018
ISO/DIS 52911-2:2017(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national
standards bodies (ISO member bodies). The work of preparing International Standards is normally
carried out through ISO technical committees. Each member body interested in a subject for which a
technical committee has been established has the right to be represented on that committee.
International organizations, governmental and non-governmental, in liaison with ISO, also take part in
the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO's adherence to the World Trade Organization (WTO)
principles in the Technical Barriers to Trade (TBT) see the following URL:
www.iso.org/iso/foreword.html.
The committee responsible for this document is Technical Committee ISO/TC 261. ISO 52911-2 was
prepared by Technical Committee ISO/TC 261, Additive Manufacturing in cooperation with ASTM F42
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.
Under the general title Additive manufacturing — Technical Design Guideline for Powder Bed Fusion
there are more standards under development, for example for Laser-based Powder Bed Fusion of
Metals.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 52911-2 is based on the VDI-Guideline (The Association of German Engineers) VDI 3405 Part 3
Additive Manufacturing processes, rapid manufacturing — Design rules for part production using laser
sintering and Laser-based Powder Bed Fusion of Metals.
The purpose of this Guideline is to provide support for technology users when designing parts that need
to be manufactured by means of Laser-based Powder Bed Fusion of Metals. Furthermore, this guideline
aims to extend the ISO/ASTM DIS 52910 Standard Practice/Guide for Design for Additive
Manufacturing with a focus on the powder bed fusion process.
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Introduction
Laser-based Powder Bed Fusion of Polymers (LB-PBF-P) describes an Additive Manufacturing (AM)
process and offers an additional manufacturing option alongside established processes. LB-PBF-P 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 giving
them appropriate consideration at the design stage and when selecting the manufacturing process. In
the case of LB-PBF-P 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 LB-PBF-P offers
designers and manufacturers with a high degree of freedom and this requires an understanding about
the possibilities and limitations of the process.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 52911-2:2017(E)
Additive manufacturing — Technical Design Guideline for Powder
Bed Fusion — Part 2: Laser-based Powder Bed Fusion of Polymers
1 Scope
This standard aims to give design and production engineers a working basis which enables them to have
informed consideration about the use of Laser-based Powder Bed Fusion of Polymers. This standard describes
the features of Laser-based Powder Bed Fusion of Polymers and provides detailed design recommendations.
Some of the fundamental principles can also be applied to other AM processes, provided that due
considerations are given to the process-specific features. The purpose of this standard is to help practitioners
explore the benefits of Laser-based Powder Bed Fusion of Polymers and recognising the process-related
limitations when designing parts.
The document also provides a state of the art review of design guidelines associated with the use of Powder
Bed Fusion by bringing together relevant knowledge about this process and to extend the scope of
ISO/ASTM DIS 52910.
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.
ISO 17296-2:2015, Additive manufacturing — General principles — Part 2: Overview of process categories and
feedstock
ISO 17296-3:2014, Additive manufacturing — General principles — Part 3: Main characteristics and
corresponding test methods
ISO/ASTM DIS 52910, Standard Practice — Guide for Design for Additive Manufacturing
ISO/ASTM DIS 52901:2015, Additive manufacturing — General principles — Requirements for purchased AM
parts
ISO/ASTM 52900:2015, Additive manufacturing — General principles — Terminology
ISO/ASTM 52915:2016, Standard Specification for Additive Manufacturing File Format (AMF) Version 1.2
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3 Terms and definitions
For the purposes of this standard, the terms and definitions as per ISO/ASTM 52900:2015 and the following
terms and definitions apply:
3.1
curl effect
thermal and residual stress effects
dimensional distortion as the printed part cools and solidifies after being
built
3.2
downskin area
D
(sub-)area whose normal vector in relation to z-axis is negative (Figure 1)
3.3
downskin angle
δ
the angle between the plane of the build platform and the downskin area whose value lies between 0° (parallel
to the build platform) and 90° (perpendicular to the build platform) (Figure 1)
3.4
upskin area
U
(sub-)area whose normal vector n�� in relation to z-axis is positive (Figure 1)
3.5
upskin angle
ν
angle between the build platform plane and an upskin area whose value lies between 0° (parallel to the build
platform) and 90° (perpendicular to the build platform) (Figure 1)
Figure 1 — Upskin and downskin areas U and D, upskin and downskin angles υ and δ, normal vector ����
[SOURCE: [0] VDI 3405 Part 3:2015]
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4 Symbols and abbreviations
4.1 Symbols
The following symbols are used throughout this standard, see Table 1:
Table 1 — Symbols
Symbol Designation Unit
a overhang mm
2
D downskin area mm
2
I island mm
��� normal vector —
Ra mean roughness µm
Rz average surface roughness µm
2
U upskin area
mm
δ downskin angle °
υ upskin angle °
4.2 Abbreviations
The following abbreviations are used throughout this standard:
AM Additive Manufacturing
AMF Additive Manufacturing File Format
DICOM Digital Imaging and Communications in Medicine
P part
CAD Computer Aided Design
CT Computer Tomography
HIP Hot Isostatic Pressing
MRI Magnetic Resonance Imaging
LB-PBF Laser-based Powder Bed Fusion
LB-PBF-M Laser-based Powder Bed Fusion of Metals (also known as e.g. Laser Beam Melting, Selective
Laser Melting)
LB-PBF-P Laser-based Powder Bed Fusion of Polymers (also known as e.g. Laser Beam Melting, Selective
Laser Melting)
PBF Powder Bed Fusion
STL STereoLithography format or Surface Tessellation Language
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5 Characteristics of Powder Bed Fusion Processes
5.1 General
Consideration must be given to the specific characteristics of the manufacturing process used in order to
optimise the design of a part. Examples of the features of Additive Manufacturing processes which need to be
taken into consideration during the design and process planning stages are listed below.
5.2 Size of the Parts
The size of the parts is limited by the working area/working volume of the PBF-machine. Also, the occurrence
of cracks and deformation due to residual stresses limits the maximal part size. Another important practical
factor that limits 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 cost of powder needed to fill the bed to the required
volume (part depth x bed area) may be a consideration. Powder reuse rules impact this cost significantly. If no
reuse is allowed, then all powder is scrapped regardless of volume solidified.
5.3 Typical Advantages of the PBF process
PBF processes can be advantageous for manufacturing parts where the following points are relevant:
— Parts can be manufactured to near-net shape (i.e. close to the finished shape and size), without further
post processing tools, in a single process step.
— Degrees of design freedom for parts are typically high. Limitations of conventional manufacturing
processes d
...
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