CEN ISO/ASTM TR 52952:2023

Additive Manufacturing of metals - Feedstock materials - Correlating of rotating drum measurement with powder spreadability in PBF-LB machines (ISO/ASTM TR 52952:2023)

This document provides an example of the relation between the characterization of certain macroscopic properties of metallic powders and their spreadability in an PBF-LB/M AM machines.
This relation is based on a new technique combining measurements inside a PBF-LB/M machine and image processing developed to quantify the homogeneity of the powder bed layers during spreading.
In this document, the flowability of five metal powders are investigated with an automated rotating drum method, whose dynamic cohesive index measurement is shown to establish a correlation with the spreadability of the powder during the layer deposition operation. Furthemore, the particule size distribution (PSD) and morphology of each powder is characterized before testing by static image analysis method (according to ISO 13322-1).
The general principle of the method is described in Figure 1.

Additive Fertigung von Metallen - Ausgangsmaterialien - Korrelation zwischen Drehtrommelmessungen und der Pulververteilbarkeit in PBF-LB-Maschinen (ISO/ASTM TR 52952:2023)

Dieses Dokument enthält ein Beispiel für den Zusammenhang zwischen der Charakterisierung bestimmter makroskopischer Eigenschaften von Metallpulvern und deren Auftragsfähigkeit bei PBF-LB-/M-AM-Maschinen.
Dieser Zusammenhang basiert auf einem neuen Verfahren, das Messungen innerhalb von PBF-LB-/M-Maschinen und Bildverarbeitung kombiniert und entwickelt wurde, um die Homogenität der Pulverbettschichten während des Auftrags zu quantifizieren.
In diesem Dokument wird in einem Verfahren mit automatisierter Drehtrommel das Fließverhalten von fünf Metallpulvern untersucht, dessen Messung des dynamischen Kohäsionsindex nachweislich einen Zusammenhang mit der Auftragsfähigkeit des Pulvers während des Schichtauftrags herstellt. Zudem wird vor der Prüfung mittels eines statischen Bildanalyseverfahrens (nach ISO 13322 1) die Teilchengrößenverteilung (PSD) und Morphologie jedes Pulvers charakterisiert.
Das Grundprinzip des Verfahrens ist in Bild 1 dargestellt.

Fabrication additive de métaux - Matières premières - Corrélation de la mesure du tambour rotatif avec la capacité d'étalement de la poudre dans les machines PBF-LB (ISO/ASTM TR 52952:2023)

Le présent document fournit un exemple de la relation entre la caractérisation de certaines propriétés macroscopiques des poudres métalliques et leur étalabilité dans les machines PBF-LB/M de FA.
Cette relation repose sur une nouvelle technique combinant les mesurages à l’intérieur de la machine PBF-LB/M et le traitement d’image, développée pour quantifier l’homogénéité des couches du lit de poudre pendant l’étalement.
Dans le présent document, la coulabilité de cinq poudres métalliques est étudiée en utilisant une méthode automatisée avec un tambour rotatif, dont le mesurage de l’indice de cohésion dynamique est représenté pour établir une corrélation avec l’étalabilité de la poudre pendant l’opération de dépôt des couches. De plus, la distribution granulométrique (PSD) et la morphologie de chaque poudre sont caractérisées avant l’essai par une méthode d’analyse d’image statique (conformément à l’ISO 13322-1).
Le principe général de la méthode est décrit à la Figure 1.

Dodajalna izdelava kovinskih izdelkov - Surovine - Korelacija med meritvami rotirajočega bobna in raztresljivostjo prahu v strojih za spajanje prahu na podlagi z laserskim žarkom (PBF-LB) (ISO/ASTM TR 52952:2023)

Zrnati materiali in fini prah se pogosto uporabljajo pri industrijskih načinih uporabe. Za nadzor in optimizacijo predelovalnih metod je treba natančno opredeliti lastnosti teh materialov. Metode karakterizacije so povezane z lastnostmi zrn (granulometrija, morfologija, kemična sestava itn.) in obnašanjem razsutega prahu (sipkost, gostota, stabilnost mešanice, elektrostatične lastnosti ipd.). Kompleksno obnašanje zrnatega in prašnatega materiala je spodbudilo razvoj dodatnih tehnik za pridobivanje ponovljivih rezultatov, ki jih je mogoče interpretirati. To se nanaša na različna področja več industrijskih panog: aditivna proizvodnja, predelava hrane, farmacevtski izdelki, ravnanje z razsutim materialom. To tehnično poročilo se osredotoča na aditivno proizvodnjo. Kovinski prah se pogosto uporablja v postopkih aditivne proizvodnje (AM), ki vključujejo spajanje prahu v postelji (LBM, EBM ipd.) ali brizganje veziva. Med takšnim delovanjem se z ravnilom ali z rotirajočim valjem ustvarjajo zaporedne tanke plasti prahu. Vsaka plast se nato delno sintra ali tali z energijskim žarkom ali zlepi z vezivom, da se izdelajo deli. Debelina plasti določa navpično ločljivost tiskalnika; tanka plast omogoča boljšo ločljivost. Prah je čim bolj fin, da lahko nastane tanka plast. Pri manjših velikostih zrn se običajno povečuje povezanost in verjetno se zmanjšuje raztresljivost, kot je določena v standardu ASTM F42/ISO/TC 261. Na kakovost delov, izdelanih z aditivno proizvodnjo, tako neposredno vplivajo lastnosti sipkosti prahu.
Vizualno opazovanje homogenosti plasti je običajno edini način, da lahko upravljavci med ponovnim nanašanjem plasti količinsko opredelijo raztresljivost prahu. Vendar pa naj se ob upoštevanju lastnosti prahu glede na njegovo raztresljivost med nanašanjem plasti vnaprej zagotovi stroškovno učinkovitejši način razvrščanja in izbire optimalnih kombinacij prahu in hitrosti ponovnega nanašanja plasti.
Cilj tega tehničnega poročila je predstaviti primer, kako je mogoče karakterizacijo makroskopskih lastnosti kovinskega prahu povezati z njihovo raztresljivostjo v tiskalnikih s spajanjem prahu v postelji (LBM). Razvita je bila nova tehnika, ki združuje meritve znotraj tiskalnika s spajanjem prahu v postelji in obdelavo slik za količinsko opredelitev homogenosti plasti prahu v postelji med ponovnim nanašanjem plasti. Poleg tega je bila raziskana sipkost štirih vrst kovinskega prahu z avtomatizirano metodo rotirajočega bobna, pri kateri se je izkazalo, da je dinamično merjenje indeksa kohezije soodvisno od raztresljivosti prahu med ponovnim nanašanjem plasti. Poleg tega sta bila pred preskusom PSD in morfologija vsake vrste prahu za vsako serijo opredeljena z metodo analize statičnih slik (ISO_13322-1_2014). Splošno načelo raziskave je predstavljeno na sliki 1.

General Information

• Status: Published
• Publication Date: 04-Jul-2023
• ICS: 25.030 - Additive manufacturing
• Technical Committee: CEN/TC 438 - Additive Manufacturing
• Drafting Committee: CEN/TC 438 - Additive Manufacturing
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 05-Jul-2023
• Due Date: 05-Oct-2023
• Completion Date: 05-Jul-2023
• Ref Project: SIST-TP CEN ISO/ASTM TR 52952:2023 - Additive Manufacturing of metals - Feedstock materials - Correlating of rotating drum measurement with powder spreadability in PBF-LB machines (ISO/ASTM TR 52952:2023)

Overview

CEN ISO/ASTM TR 52952:2023 - "Additive Manufacturing of metals - Feedstock materials - Correlating of rotating drum measurement with powder spreadability in PBF‑LB machines" - provides a practical example linking macroscopic powder characterization to in‑machine spreadability for powder bed fusion with laser (PBF‑LB/M). The Technical Report describes a combined approach using an automated rotating drum test (dynamic cohesive index), in‑machine measurements, and image processing to quantify powder bed layer homogeneity during recoating. Particle size distribution (PSD) and morphology are characterized by static image analysis (ISO 13322‑1) prior to testing.

Key Topics

• Powder spreadability in PBF‑LB: Defines spreadability as the feedstock’s ability to form uniform, flat layers suitable for layer‑wise fusion, and links visual layer homogeneity to measurable powder properties.
• Rotating drum flowability: Uses an automated rotating drum method to measure dynamic behaviour and a dynamic cohesive index that correlates with recoating performance.
• Particle characterization (PSD & morphology): Employs static image analysis (ISO 13322‑1) to document particle size distribution and shape before spreadability testing.
• Combined measurement technique: Integrates in‑machine measurements and image processing to quantify layer homogeneity and establish correlations between laboratory flow tests and real recoating behaviour.
• Terminology and definitions: Clarifies terms such as cohesiveness and powder flowability, referencing ISO/ASTM 52900 and related standards.

Applications

This Technical Report is practical for:

• Additive manufacturing engineers and operators seeking objective metrics to predict powder recoating performance and reduce trial‑and‑error setup in PBF‑LB machines.
• Powder producers and quality managers who need to qualify metal feedstock (Al, Ti, Ni‑based, etc.) for AM processes and specify acceptable flowability ranges.
• R&D teams and materials scientists developing new metal powders or surface treatments to improve spreadability.
• Standards and compliance specialists evaluating test methods to support purchasing, supplier qualification, and process control.

Practical benefits include improved powder selection, faster process optimization (layer thickness and recoating speed), better part quality through controlled layer homogeneity, and reduced scrap costs.

Related Standards

• ISO/ASTM 52900 - Additive manufacturing - General principles - Fundamentals and vocabulary
• ISO 13322‑1 - Image analysis methods for particle size distribution (static image analysis)
• ISO/ASTM 52907 - (Referenced for powder flowability context)

CEN ISO/ASTM TR 52952:2023 is a useful, application‑focused resource for correlating laboratory powder flow tests (rotating drum) with actual powder spreadability in industrial PBF‑LB machines, enabling more reliable feedstock qualification and process control.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2023
Dodajalna izdelava kovinskih izdelkov - Surovine - Korelacija med meritvami
rotirajočega bobna in raztresljivostjo prahu v strojih za spajanje prahu na podlagi
z laserskim žarkom (PBF-LB) (ISO/ASTM TR 52952:2023)
Additive Manufacturing of metals - Feedstock materials - Correlating of rotating drum
measurement with powder spreadability in PBF-LB machines (ISO/ASTM TR
52952:2023)
Additive Fertigung von Metallen - Ausgangsmaterialien - Korrelation zwischen der
Messung der rotierenden Trommel und der Pulververteilbarkeit in PBF-LB-Maschinen
(ISO/ASTM TR 52952:2023)
Fabrication additive de métaux - Matières premières - Corrélation de la mesure du
tambour rotatif avec la capacité d'étalement de la poudre dans les machines PBF-LB
(ISO/ASTM TR 52952:2023)
Ta slovenski standard je istoveten z: CEN ISO/ASTM TR 52952:2023
ICS:
25.030 3D-tiskanje Additive manufacturing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN ISO/ASTM TR 52952
TECHNICAL REPORT
RAPPORT TECHNIQUE
July 2023
TECHNISCHER REPORT
ICS 25.030
English Version
Additive Manufacturing of metals - Feedstock materials -
Correlating of rotating drum measurement with powder
spreadability in PBF-LB machines (ISO/ASTM TR
52952:2023)
Fabrication additive de métaux - Matières premières - Additive Fertigung von Metallen - Ausgangsmaterialien
Corrélation de la mesure du tambour rotatif avec la - Korrelation zwischen der Messung der rotierenden
capacité d'étalement de la poudre dans les machines Trommel und der Pulververteilbarkeit in PBF-LB-
PBF-LB (ISO/ASTM TR 52952:2023) Maschinen (ISO/ASTM TR 52952:2023)

This Technical Report was approved by CEN on 13 June 2023. It has been drawn up by the Technical Committee CEN/TC 438.

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. CEN ISO/ASTM TR 52952:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (CEN ISO/ASTM TR 52952:2023) 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.
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.
Endorsement notice
The text of ISO/ASTM TR 52952:2023 has been approved by CEN as CEN ISO/ASTM TR 52952:2023
without any modification.
TECHNICAL ISO/ASTM TR
REPORT 52952
First edition
2023-06
Additive manufacturing of metals —
Feedstock materials — Correlating
of rotating drum measurement with
powder spreadability in PBF-LB
machines
Fabrication additive de métaux — Matières premières — Corrélation
de la mesure du tambour rotatif avec la capacité d'étalement de la
poudre dans les machines PBF-LB
Reference number
ISO/ASTM TR 52952:2023(E)
© ISO/ASTM International 2023
ISO/ASTM TR 52952:2023(E)
© 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: [phone] Phone: [phone]
Fax: [phone]
Email: [e-mail] Email: [e-mail]
Website: www.iso.org Website: www.astm.org
Published in Switzerland
ii
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Designation . 2
5 Methodology .2
5.1 General principle . 2
5.2 Powder selection . 3
5.3 Layer homogeneity evaluation . 3
5.4 Rotating drum . 4
6 Results and discussion .5
6.1 Spreadability . 5
6.2 Rotating drum analysis . 7
6.2.1 Experimental protocol . 7
6.2.2 Experimental results . 7
6.3 Discussion . 9
7 Conclusions .10
8 Additional data .11
9 Perspectives .12
Bibliography .13
iii
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(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 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).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
Introduction
Granular materials and fine powders are widely used in industrial applications. To support control and
optimize processing methods, these materials have to be precisely characterized. Characterization
methods are related either to the properties of the grains (granulometry, morphology, chemical
composition, etc.) or to the behaviour of the bulk powder (flowability, density, blend stability,
electrostatic properties, etc.). The complex behaviours of granular and powder materials have motivated
the development of numerous techniques to obtain reproducible and interpretable results. Many
industries are concerned in different fields: additive manufacturing, food processing, pharmaceuticals,
bulk material handling. This document is focused on Additive Manufacturing (AM).
Metallic powders are widely used in AM processes involving powder bed fusion (PBF-LB/M PBF-EB/M
etc.) or binder jetting. During such operations, successive thin layers of powder are deposited with a
blade or with a rotating cylinder. Each layer is then fused (most commonly melted) by an energy beam
or joined by an adhesive binder to build the parts. The layer thickness defines the vertical resolution
of the process; a thin layer leads to a better resolution. In order to obtain a thin layer, the powder is as
fine as possible. However, if it is assumed that among the cohesive forces, the Van der Waal forces are
[25]
predominant, it can be stated that as the grain size decreases, cohesiveness typically increases . This
increase in cohesiveness could have an impact on the spreadability of a powder.
The quality of the parts built with AM is thus directly influenced by powder flow properties.
According to ISO/ASTM 52900, spreadability is the ability of a feedstock material to be spread out in
layers that fulfil the requirements for the AM process; this includes the ability to form a flat powder-
atmosphere interface without waves and irregularities.
Visual observation of layer homogeneity is usually the only way for operators to assess the spreadability
of powders during the spreading of new layers. However, linking the powder characteristics to its
spreadability during the layer deposition beforehand can provide a more cost-effective way to classify
and select the optimal powder and layer deposition speed combinations.
v
© ISO/ASTM International 2023 – All rights reserved

TECHNICAL REPORT ISO/ASTM TR 52952:2023(E)
Additive manufacturing of metals — Feedstock materials
— Correlating of rotating drum measurement with powder
spreadability in PBF-LB machines
1 Scope
This document provides an example of the relation between the characterization of certain macroscopic
properties of metallic powders and their spreadability in an PBF-LB/M AM machines.
This relation is based on a new technique combining measurements inside a PBF-LB/M machine and
image processing developed to quantify the homogeneity of the powder bed layers during spreading.
In this document, the flowability of five metal powders are investigated with an automated rotating
drum method, whose dynamic cohesive index measurement is shown to establish a correlation with
the spreadability of the powder during the layer deposition operation. Furthemore, the particule size
distribution (PSD) and morphology of each powder is characterized before testing by static image
analysis method (according to ISO 13322-1).
The general principle of the method is described in Figure 1.
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
cohesiveness
physical powder behaviour relating to the degree to which the attractive forces between particles
exceed the average particle mass
Note 1 to entry: Cohesive powders are qualified as powders where the attractive force between particles exceed
the average particle mass
3.2
powder flowability
ability of a solid bulk material to flow
Note 1 to entry: Powder flowability is a function of multiple factors, and particularly powder size and distribution,
see also ISO/ASTM 52907.
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
4 Designation
In this document, five powders described in Table 1 are used:
Table 1 — Designation of powders
Denomination used in this
Common designation European spefication
document
1)
Scalmalloy® AlMgSc AlMgSc_Std
2)
Inconel® NiCr Mo Nb NiCr Mo Nb_Std
22 9 22 9
AlSi Mg AlSi Mg AlSi Mg_Std
7 7 7
Titanium Fine Ti Al V Ti Al V_Fine
6 4 6 4
Inconel® Fine NiCr Mo Nb NiCr Mo Nb_Fine
22 9 22 9
5 Methodology
5.1 General principle
The general principle for comparing rotating drum measurements with powder spreading in a
PBF-LB AM machine is described in Figure 1.
Key
1 AlSi Mg
2 NiCr Mo Nb (inconel® fine)
22 9
a
Good.
b
Bad.
c
Rotating drum.
d
PBF-LM machine.
e
Regular layer.
f
Irregular layer.
Figure 1 — General principle of comparing rotating drum measurements with powder
spreading in a PBF-LB AM machine
1)  Scalmalloy is an example of a suitable product available commercially. This information is given for the
convenience of users of this document and does not constitute an endorsement by ISO of this product.
2)  Inconel is an example of a suitable product available commercially. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of this product.
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
5.2 Powder selection
The recoating performance of the powders inside a PBF-LB AM machine is evaluated experimentally
with in situ observation of layer homogeneity. Five metallic powders are selected for this study: two
Nickel alloys (NiCr Mo Nb_Std and NiCr Mo Nb_Fine), two Aluminium alloys (AlSi Mg_Std and
22 9 22 9 7
AlMgSc_Std) and one Titanium alloy (Ti Al V_Fine). Particle size distribution (PSD) is summarized in
6 4
Table 2 and shape and morphology in Table 3.
Table 2 — Summary of the PSD (D10 and D90) of the five powders (volume)
D10 D90
Powder
µm µm
AlMgSc_Std 26 66
AlSi Mg_Std 27 69
NiCr Mo Nb_Std 17 45
22 9
NiCr Mo Nb_Fine 6 27
22 9
Ti Al V_Fine 7 28
6 4
Table 3 — Shape and morphology comparison
Aspect ratio comparison
Mean P10 P50 P90
Aspect ratio (number)
µm µm µm µm
AlMgSc_Std 79,7 62,5 81,6 93,8
AlSi Mg 76,6 58,4 78,7 91,8
NiCr Mo Nb_Std 81,9 63,5 85,3 94,6
22 9
NiCr Mo Nb_Fine 81,8 63,5 85,8 93,3
22 9
Ti Al V_Fine 79,7 60,9 82,9 92,8
6 4
Bluntness comparison
Mean P10 P50 P90
Bluntness (number)
µm µm µm µm
AlMgSc_Std 74,6 54,0 74,6 95,1
AlSi Mg 75,5 57,1 75,5 93,8
NiCr Mo Nb_Std 84,3 67,9 86,7 97,2
22 9
NiCr Mo Nb_Fine 88,0 76,5 89,9 97,1
22 9
Ti Al V_Fine 85,0 70,2 87,4 96,5
6 4
Successive powder layers are deposited in the PBF-LB AM machine with no laser melting. Between
each layer deposition, a picture of the powder layer is taken by a staring camera placed inside the AM
machine. The pictures are then processed numerically to evaluate the layer homogeneity. Three powder
spreading speeds are investigated: 30 mm/s, 80 mm/s and 160 mm/s to highlight their influence on the
layer quality.
5.3 Layer homogeneity evaluation
The powder layer surface homogeneity is experimentally evaluated using a staring camera placed
orthogonal to the powder bed. After each powder spreading operation, a picture is taken. For this
experiment, the focus is made on metallic coater and 30 µm layer thickness only. For the same recoater
speed, 15 layers are created and therefore, 15 pictures are taken as well. This methodology provides a
quantitative and operator independent way to quantify the layer topography homogeneity.
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
The gathered pictures are then processed numerically to obtain "Interface Fluctuation”, a measure of
the inhomogeneity of the produced layers. The image processing analysis principle is as follow:
a) each picture is analysed separately. The picture size is 1 200 pixels × 1 200 pixels;
b) horizontal and vertical pixel intensity profiles are extracted at discrete positions of the picture [see
Figure 2 a)];
c) an average “smooth” profile is computed for each position [see Figure 2 b)];
d) interface fluctuation i
...

SLOVENSKI STANDARD
01-september-2023
Aditivna proizvodnja kovin - Surovine - Korelacija med meritvami rotirajočega
bobna in raztresljivostjo prahu v strojih za lasersko spajanje prahu v postelji (PBF-
LB) (ISO/ASTM TR 52952:2023)
Additive Manufacturing of metals - Feedstock materials - Correlating of rotating drum
measurement with powder spreadability in PBF-LB machines (ISO/ASTM TR
52952:2023)
Additive Fertigung von Metallen - Ausgangsmaterialien - Korrelation zwischen der
Messung der rotierenden Trommel und der Pulververteilbarkeit in PBF-LB-Maschinen
(ISO/ASTM TR 52952:2023)
Fabrication additive de métaux - Matières premières - Corrélation de la mesure du
tambour rotatif avec la capacité d'étalement de la poudre dans les machines PBF-LB
(ISO/ASTM TR 52952:2023)
Ta slovenski standard je istoveten z: CEN ISO/ASTM TR 52952:2023
ICS:
25.030 3D-tiskanje Additive manufacturing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN ISO/ASTM TR 52952
TECHNICAL REPORT
RAPPORT TECHNIQUE
July 2023
TECHNISCHER REPORT
ICS 25.030
English Version
Additive Manufacturing of metals - Feedstock materials -
Correlating of rotating drum measurement with powder
spreadability in PBF-LB machines (ISO/ASTM TR
52952:2023)
Fabrication additive de métaux - Matières premières - Additive Fertigung von Metallen - Ausgangsmaterialien
Corrélation de la mesure du tambour rotatif avec la - Korrelation zwischen der Messung der rotierenden
capacité d'étalement de la poudre dans les machines Trommel und der Pulververteilbarkeit in PBF-LB-
PBF-LB (ISO/ASTM TR 52952:2023) Maschinen (ISO/ASTM TR 52952:2023)

This Technical Report was approved by CEN on 13 June 2023. It has been drawn up by the Technical Committee CEN/TC 438.

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,
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United Kingdom.
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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. CEN ISO/ASTM TR 52952:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (CEN ISO/ASTM TR 52952:2023) 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.
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.
Endorsement notice
The text of ISO/ASTM TR 52952:2023 has been approved by CEN as CEN ISO/ASTM TR 52952:2023
without any modification.
TECHNICAL ISO/ASTM TR
REPORT 52952
First edition
2023-06
Additive manufacturing of metals —
Feedstock materials — Correlating
of rotating drum measurement with
powder spreadability in PBF-LB
machines
Fabrication additive de métaux — Matières premières — Corrélation
de la mesure du tambour rotatif avec la capacité d'étalement de la
poudre dans les machines PBF-LB
Reference number
ISO/ASTM TR 52952:2023(E)
© ISO/ASTM International 2023
ISO/ASTM TR 52952:2023(E)
© 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
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Published in Switzerland
ii
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Designation . 2
5 Methodology .2
5.1 General principle . 2
5.2 Powder selection . 3
5.3 Layer homogeneity evaluation . 3
5.4 Rotating drum . 4
6 Results and discussion .5
6.1 Spreadability . 5
6.2 Rotating drum analysis . 7
6.2.1 Experimental protocol . 7
6.2.2 Experimental results . 7
6.3 Discussion . 9
7 Conclusions .10
8 Additional data .11
9 Perspectives .12
Bibliography .13
iii
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(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 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).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
Introduction
Granular materials and fine powders are widely used in industrial applications. To support control and
optimize processing methods, these materials have to be precisely characterized. Characterization
methods are related either to the properties of the grains (granulometry, morphology, chemical
composition, etc.) or to the behaviour of the bulk powder (flowability, density, blend stability,
electrostatic properties, etc.). The complex behaviours of granular and powder materials have motivated
the development of numerous techniques to obtain reproducible and interpretable results. Many
industries are concerned in different fields: additive manufacturing, food processing, pharmaceuticals,
bulk material handling. This document is focused on Additive Manufacturing (AM).
Metallic powders are widely used in AM processes involving powder bed fusion (PBF-LB/M PBF-EB/M
etc.) or binder jetting. During such operations, successive thin layers of powder are deposited with a
blade or with a rotating cylinder. Each layer is then fused (most commonly melted) by an energy beam
or joined by an adhesive binder to build the parts. The layer thickness defines the vertical resolution
of the process; a thin layer leads to a better resolution. In order to obtain a thin layer, the powder is as
fine as possible. However, if it is assumed that among the cohesive forces, the Van der Waal forces are
[25]
predominant, it can be stated that as the grain size decreases, cohesiveness typically increases . This
increase in cohesiveness could have an impact on the spreadability of a powder.
The quality of the parts built with AM is thus directly influenced by powder flow properties.
According to ISO/ASTM 52900, spreadability is the ability of a feedstock material to be spread out in
layers that fulfil the requirements for the AM process; this includes the ability to form a flat powder-
atmosphere interface without waves and irregularities.
Visual observation of layer homogeneity is usually the only way for operators to assess the spreadability
of powders during the spreading of new layers. However, linking the powder characteristics to its
spreadability during the layer deposition beforehand can provide a more cost-effective way to classify
and select the optimal powder and layer deposition speed combinations.
v
© ISO/ASTM International 2023 – All rights reserved

TECHNICAL REPORT ISO/ASTM TR 52952:2023(E)
Additive manufacturing of metals — Feedstock materials
— Correlating of rotating drum measurement with powder
spreadability in PBF-LB machines
1 Scope
This document provides an example of the relation between the characterization of certain macroscopic
properties of metallic powders and their spreadability in an PBF-LB/M AM machines.
This relation is based on a new technique combining measurements inside a PBF-LB/M machine and
image processing developed to quantify the homogeneity of the powder bed layers during spreading.
In this document, the flowability of five metal powders are investigated with an automated rotating
drum method, whose dynamic cohesive index measurement is shown to establish a correlation with
the spreadability of the powder during the layer deposition operation. Furthemore, the particule size
distribution (PSD) and morphology of each powder is characterized before testing by static image
analysis method (according to ISO 13322-1).
The general principle of the method is described in Figure 1.
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
cohesiveness
physical powder behaviour relating to the degree to which the attractive forces between particles
exceed the average particle mass
Note 1 to entry: Cohesive powders are qualified as powders where the attractive force between particles exceed
the average particle mass
3.2
powder flowability
ability of a solid bulk material to flow
Note 1 to entry: Powder flowability is a function of multiple factors, and particularly powder size and distribution,
see also ISO/ASTM 52907.
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
4 Designation
In this document, five powders described in Table 1 are used:
Table 1 — Designation of powders
Denomination used in this
Common designation European spefication
document
1)
Scalmalloy® AlMgSc AlMgSc_Std
2)
Inconel® NiCr Mo Nb NiCr Mo Nb_Std
22 9 22 9
AlSi Mg AlSi Mg AlSi Mg_Std
7 7 7
Titanium Fine Ti Al V Ti Al V_Fine
6 4 6 4
Inconel® Fine NiCr Mo Nb NiCr Mo Nb_Fine
22 9 22 9
5 Methodology
5.1 General principle
The general principle for comparing rotating drum measurements with powder spreading in a
PBF-LB AM machine is described in Figure 1.
Key
1 AlSi Mg
2 NiCr Mo Nb (inconel® fine)
22 9
a
Good.
b
Bad.
c
Rotating drum.
d
PBF-LM machine.
e
Regular layer.
f
Irregular layer.
Figure 1 — General principle of comparing rotating drum measurements with powder
spreading in a PBF-LB AM machine
1)  Scalmalloy is an example of a suitable product available commercially. This information is given for the
convenience of users of this document and does not constitute an endorsement by ISO of this product.
2)  Inconel is an example of a suitable product available commercially. This information is given for the convenience
of users of this document and does not constitute an endorsement by ISO of this product.
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
5.2 Powder selection
The recoating performance of the powders inside a PBF-LB AM machine is evaluated experimentally
with in situ observation of layer homogeneity. Five metallic powders are selected for this study: two
Nickel alloys (NiCr Mo Nb_Std and NiCr Mo Nb_Fine), two Aluminium alloys (AlSi Mg_Std and
22 9 22 9 7
AlMgSc_Std) and one Titanium alloy (Ti Al V_Fine). Particle size distribution (PSD) is summarized in
6 4
Table 2 and shape and morphology in Table 3.
Table 2 — Summary of the PSD (D10 and D90) of the five powders (volume)
D10 D90
Powder
µm µm
AlMgSc_Std 26 66
AlSi Mg_Std 27 69
NiCr Mo Nb_Std 17 45
22 9
NiCr Mo Nb_Fine 6 27
22 9
Ti Al V_Fine 7 28
6 4
Table 3 — Shape and morphology comparison
Aspect ratio comparison
Mean P10 P50 P90
Aspect ratio (number)
µm µm µm µm
AlMgSc_Std 79,7 62,5 81,6 93,8
AlSi Mg 76,6 58,4 78,7 91,8
NiCr Mo Nb_Std 81,9 63,5 85,3 94,6
22 9
NiCr Mo Nb_Fine 81,8 63,5 85,8 93,3
22 9
Ti Al V_Fine 79,7 60,9 82,9 92,8
6 4
Bluntness comparison
Mean P10 P50 P90
Bluntness (number)
µm µm µm µm
AlMgSc_Std 74,6 54,0 74,6 95,1
AlSi Mg 75,5 57,1 75,5 93,8
NiCr Mo Nb_Std 84,3 67,9 86,7 97,2
22 9
NiCr Mo Nb_Fine 88,0 76,5 89,9 97,1
22 9
Ti Al V_Fine 85,0 70,2 87,4 96,5
6 4
Successive powder layers are deposited in the PBF-LB AM machine with no laser melting. Between
each layer deposition, a picture of the powder layer is taken by a staring camera placed inside the AM
machine. The pictures are then processed numerically to evaluate the layer homogeneity. Three powder
spreading speeds are investigated: 30 mm/s, 80 mm/s and 160 mm/s to highlight their influence on the
layer quality.
5.3 Layer homogeneity evaluation
The powder layer surface homogeneity is experimentally evaluated using a staring camera placed
orthogonal to the powder bed. After each powder spreading operation, a picture is taken. For this
experiment, the focus is made on metallic coater and 30 µm layer thickness only. For the same recoater
speed, 15 layers are created and therefore, 15 pictures are taken as well. This methodology provides a
quantitative and operator independent way to quantify the layer topography homogeneity.
© ISO/ASTM International 2023 – All rights reserved

ISO/ASTM TR 52952:2023(E)
The gathered pictures are then processed numerically to obtain "Interface Fluctuation”, a measure of
the inhomogeneity of the produced layers. The image processing analysis principle is as follow:
a) each picture is analysed separately. The picture size is 1 200 pixels × 1 200 pixels;
b) horizontal and vertical pixel intensity profiles are extracted at discrete positions of the picture [see
Figure 2 a)];
c) an average “smooth” profile is computed for each position [see Figure 2 b)];
d) interface fluctuation is then com
...