CEN/TC 438 - Additive Manufacturing

This document provides guidance and requirements for risk assessment and implementation of prevention and protection measures relating to additive manufacturing with metallic powders.
The risks covered by this document concern all sub-processes composing the manufacturing process, including the management of waste.
This document does not specify requirements for the design of machinery and equipment used for additive manufacturing.

This document provides specifications and illustrations for the positioning and orientation of parts with regards with coordinate systems and testing methodologies for additive manufacturing (AM) technologies in an effort to standardize the method of representation used by AM users, producers, researchers, educators, press/media, and others, particularly when reporting results from testing of parts made on AM systems. Included specifications cover coordinate systems and the location and orientation of parts. It is intended to be in accordance with the principles of ISO 841 and to clarify the specific adaptation of those principles for additive manufacturing.

This document specifies the features of electron beam powder bed fusion of metals (PBF-EB/M) and provides detailed design recommendations.
Some of the fundamental principles are also applicable to other additive manufacturing (AM) processes, provided that due consideration is given to process-specific features.
This document also provides a state of the art review of design guidelines associated with the use of powder bed fusion (PBF) by bringing together relevant knowledge about this process and by extending the scope of ISO/ASTM 52910.

This document specifies the general principles to be followed when test specimens of thermoplastic materials are prepared by laser-based powder bed fusion (PBF-LB/P), which is commonly known as laser sintering. The (PBF-LB/P) process is used to prepare test specimens layer upon layer in which thermal energy selectively fuses regions of a powder bed. This document provides a basis for establishing reproducible and reportable sintering conditions. Its purpose is to promote uniformity in describing the main process parameters, build orientation of the sintering process and also to establish uniform practice in reporting sintering conditions.
This document does not specify the test procedure itself.

This document provides guidance and recommendations for the qualification of polymeric materials intended for laser-based powder bed fusion of polymers (PBF-LB/P). The parameters and recommendations presented in this document relate mainly to the material polyamide 12 (PA12), but references are also made to polyamide 11 (PA11). The parameters and recommendations set forth herein cannot be applicable to other polymeric materials.

This document covers supplementary guidelines for evaluation of mechanical properties including static/quasi-static and dynamic testing of metals made by additive manufacturing (AM) to provide guidance toward reporting when results from testing of as-build specimen or those excised from printed parts made by this technique or both.
This document is provided to leverage already existing standards. Guidelines are provided for mechanical properties measurements and reporting for additively manufactured metallic specimen as well as those excised from parts.
This document does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health and environmental practices and determine the applicability of regulatory limitations prior to use.
This document expands upon the nomenclature of ISO/ASTM 52900 and principles of ISO/ASTM 52921 and extends them specifically to metal additive manufacturing. The application of this document is primarily intended to provide guidance on orientation designations in cases where meaningful orientation/direction for AM cannot be obtained from available test methods.

This document is focused on the management of the round robin study (RRS) and can provide guidance for the scope development, planning, and execution of the RRS study. It can provide guidance to identify the feedstock, machine operations, process controls, and post-processing operations prior to running the study. RR organizers can identify controlled and free parameters in the study. This document can also provide guidance on the selection and use of test methods that can be applicable. The RRS investigates the variations found in AM parts. The outcome of the study can be used to improve the maturation of AM technologies.
A RRS, as described in this document, is different from an inter-laboratory comparison because an inter-laboratory study establishes the variability in a measurement method when undertaken by multiple users on a well-controlled artefact.

This document establishes and defines terms used in additive manufacturing (AM) technology, which applies the additive shaping principle and thereby builds physical three-dimensional (3D) geometries by successive addition of material.
The terms have been classified into specific fields of application.

This document is intended to serve as a best practice for the identification and “seeding” of nondestructively detectable flaw replicas of metal alloy PBF and DED processes. Three seeding categories are described:
a) process flaws through CAD design;
b) build parameter manipulation;
c) subtractive manufacturing.
These include flaws present within as-deposited materials, post heat-treated or HIP processed material, and those flaws made detectable because of post-processing operations. Geometrical aspects or measurement are not the subjects of this document.
WARNING — This document does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

This document includes the creation of optimized data for medical additive manufacturing (MAM). These data are generated from static modalities, such as magnetic resonance imaging (MRI), computed tomography (CT). This document addresses improved medical image data, and medical image data acquisition processing and optimization approaches for accurate solid medical models, based on real human and animal data.
Solid medical models are generally created from stacked 2D images output from medical imaging systems. The accuracy of the final model depends on the resolution and accuracy of the original image data. The main factors influencing accuracy are the resolution of the image, the amount of image noise, the contrast between the tissues of interest and artefacts inherent in the imaging system.

This document addresses installation qualification (IQ), operational qualification (OQ), and performance qualification (PQ) issues directly related to the additive manufacturing system that has a direct influence on the consolidation of material. The first three elements of process validation, process mapping, risk assessment, and validation planning, are necessary pre-conditions to machine qualification, however, they are outside the scope of this document.
This document covers issues directly related to the AM equipment and does not cover feedstock qualification or post processing beyond powder removal.
Physical facility, personnel, process and material issues are only included to the extent necessary to support machine qualification.

This document describes a method for defining requirements for plastic materials used in extrusion-based additive manufacturing (AM) processes. Materials include unfilled, filled, and reinforced plastic materials suitable for processing into parts. These materials can also contain special additives (e.g. flame retardants, stabilizers, etc.). Processes include all material extrusion-based AM processes.
This document is intended for use by manufacturers of materials, feedstocks, plastic parts or any combination of the three using material extrusion-based AM.
NOTE       In some cases, material manufacturers can also be feedstock manufacturers. In other cases, a material manufacturer can supply materials (example: pellets) to a feedstock manufacturer (example: converter of pellets into filaments).
This document does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health, and environmental practices and determine the applicability of regulatory limitations prior to use.

This document covers the principal considerations which apply to data exchange for additive manufacturing. It specifies terms and definitions which enable information to be exchanged describing geometries or parts such that they can be additively manufactured. The data exchange method outlines file type, data enclosed formatting of such data and what this can be used for.
This document
—     enables a suitable format for data exchange to be specified,
—     describes the existing developments for additive manufacturing of 3D geometries,
—     outlines existing file formats used as part of the existing developments, and
—     enables understanding of necessary features for data exchange, for adopters of this document.
This document is aimed at users and producers of additive manufacturing processes and associated software systems. It applies wherever additive processes are used, and to the following fields in particular:
—     producers of additive manufacturing systems and equipment including software;
—     software engineers involved in CAD/CAE systems;
—     reverse engineering systems developers;
—     test bodies wishing to compare requested and actual geometries.

This document specifies requirements and test methods for the qualification and re-qualification of laser beam machines for metal powder bed fusion additive manufacturing for aerospace applications.
It can also be used to verify machine features during periodic inspections or following maintenance and repair activities.

This document describes a method for defining requirements and assuring component integrity for plastic parts created using material extrusion based additive manufacturing processes. It relates to the process, equipment and operational parameters. Processes include all material extrusion based additive manufacturing processes.
This document is intended for use by AM users and customers procuring such parts.

This document specifies requirements for the qualification of operators of laser metal powder bed fusion machines and equipment for additive manufacturing in aerospace applications.
This document is applicable if the operator qualification testing is required by contract or by application standards in the field of aerospace.

1.1 This practice describes the operation and production control of metal powder bed fusion (PBF) machines and processes to meet critical applications such as commercial aerospace components and medical implants. The requirements contained herein are applicable for production components and mechanical test specimens using powder bed fusion (PBF) with both laser and electron beams.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.
1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for the Development of International Standards, Guides and Recom-mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

This document provides the specification for the Additive Manufacturing File Format (AMF), an interchange format to address the current and future needs of additive manufacturing technology.
This document specifies the requirements for the preparation, display and transmission for the AMF. When prepared in a structured electronic format, strict adherence to an extensible markup language (XML)[1] schema supports standards-compliant interoperability.
NOTE       A W3C XML schema definition (XSD) for the AMF is available from ISO from http://standards.iso.org/iso/52915 and from ASTM from www.astm.org/MEETINGS/images/amf.xsd. An implementation guide for such an XML schema is provided in Annex A.
It is recognized that there is additional information relevant to the final part that is not covered by the current version of this document. Suggested future features are listed in Annex B.
This document does not specify any explicit mechanisms for ensuring data integrity, electronic signatures and encryptions.

The use of Additive Manufacturing (AM) enables the fabrication of geometrically complex components by accurately depositing materials in a controlled way. Technological progress in AM hardware, software, as well as the opening of new markets demand for higher flexibility and greater efficiency in today's products, encouraging research into novel materials with functionally graded and high-performance capabilities. This has been termed as Functionally Graded Additive Manufacturing (FGAM), a layer-by-layer fabrication technique that involves gradationally varying the ratio of the material organization within a component to meet an intended function. As research in this field has gained worldwide interest, the interpretations of the FGAM concept requires greater clarification. The objective of this document is to present a conceptual understanding of FGAM. The current-state of art and capabilities of FGAM technology will be reviewed alongside with its challenging technological obstacles and limitations. Here, data exchange formats and some of the recent application is evaluated, followed with recommendations on possible strategies in overcoming barriers and future directions for FGAM to take off.

This document provides technical specifications for metallic powders intended to be used in additive manufacturing and covers the following aspects:
—          documentation and traceability;
—          sampling;
—          particle size distribution;
—          chemical composition;
—          characteristic densities;
—          morphology;
—          flowability;
—          contamination;
—          packaging and storage.
This document does not deal with safety aspects.
In addition, this document gives specific requirements for used metallic powders in additive manufacturing.

This document gives requirements, guidelines and recommendations for using additive manufacturing (AM) in product design.
It is applicable during the design of all types of products, devices, systems, components or parts that are fabricated by any type of AM system. This document helps determine which design considerations can be utilized in a design project or to take advantage of the capabilities of an AM process.
General guidance and identification of issues are supported, but specific design solutions and process-specific or material-specific data are not supported.
The intended audience comprises three types of users:
—          designers who are designing products to be fabricated in an AM system and their managers;
—          students who are learning mechanical design and computer-aided design; and
—          developers of AM design guidelines and design guidance systems.

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.

This document covers the general description of benchmarking test piece geometries along with quantitative and qualitative measurements to be taken on the benchmarking test piece(s) to assess the performance of additive manufacturing (AM) systems.
This performance assessment can serve the following two purposes:
—                                      AM system capability evaluation;
—                                      AM system calibration.
The benchmarking test piece(s) is (are) primarily used to quantitatively assess the geometric performance of an AM system. This document describes a suite of test geometries, each designed to investigate one or more specific performance metrics and several example configurations of these geometries into test piece(s). It prescribes quantities and qualities of the test geometries to be measured but does not dictate specific measurement methods. Various user applications can require various grades of performance. This document discusses examples of feature configurations, as well as measurement uncertainty requirements, to demonstrate low and high grade examination and performance. This document does not discuss a specific procedure or machine settings for manufacturing a test piece, which are covered by ASTM F 2971 and other relevant process specific specifications.

This document specifies the features of laser-based powder bed fusion of metals (PBF-LB/M) and provides detailed design recommendations.
Some of the fundamental principles are also applicable to other additive manufacturing (AM) processes, provided that due consideration is given to process-specific features.
This document also provides a state of the art review of design guidelines associated with the use of powder bed fusion (PBF) by bringing together relevant knowledge about this process and by extending the scope of ISO/ASTM 52910.

ISO/ASTM 52901:2017 defines and specifies requirements for purchased parts made by additive manufacturing.
ISO/ASTM 52901:2017 gives guidelines for the elements to be exchanged between the customer and the part provider at the time of the order, including the customer order information, part definition data, feedstock requirements, final part characteristics and properties, inspection requirements and part acceptance methods.
ISO/ASTM 52901:2017 is applicable for use as a basis to obtain parts made by additive manufacturing that meet minimum acceptance requirements. More stringent part requirements can be specified through the addition of one or more supplementary requirements at the time of the order.

ISO 17296-2:2015 describes the process fundamentals of Additive Manufacturing (AM). It also gives an overview of existing process categories, which are not and cannot be exhaustive due to the development of new technologies. ISO 17296-2:2015 explains how different process categories make use of different types of materials to shape a product's geometry. It also describes which type of material is used in different process categories. Specification of feedstock material and requirements for the parts produced by combinations of different processes and feedstock material will be given in subsequent separate standards and are therefore not covered by ISO 17296-2:2015. ISO 17296-2:2015 describes the overreaching principles of these subsequent standards.

ISO 17296-3:2014 covers the principal requirements applied to testing of parts manufactured by additive manufacturing processes. It specifies main quality characteristics of parts, specifies appropriate test procedures, and recommends the scope and content of test and supply agreements.
ISO 17296-3:2014 is aimed at machine manufacturers, feedstock suppliers, machine users, part providers, and customers to facilitate the communication on main quality characteristics. It applies wherever additive manufacturing processes are used.

This document specifies requirements and describes aspects for the lifecycle management of metal feedstock materials for powder based additive manufacturing processes. Those aspects include:
• Powder properties,
• Powder lifecycle,
• Test methods and
• Powder quality assurance.
Note : This document can be used by manufacturers of metal powders, purchasers of powder feedstock for additive manufacturing, those responsible for the quality assurance of additively manufactured parts and suppliers of measurement and testing equipment for characterizing metal powders for use in powder-based additive manufacturing processes

This document specifies test methods to determine particle emissions (including ultrafine particles) and specified VOCs (including aldehydes) from Material Extrusion(ME) processes often used in non-industrial environments such as school, homes and office spaces in an Emission Test Chamber (ETC) under specified test conditions. However, these tests may not accurately predict real-world results.
This document describes a conditioning method using an ETC with controlled temperature, humidity, air exchange rate, air velocity, and procedures for monitoring, storage, analysis, calculation, and reporting of emission rates.
This document is intended to cover a Fused Filament Fabrication (FFF) type desktop 3D printer using thermoplastic materials. The primary purpose of this document is to quantify particle and chemical emission rates emitted from a specific ME type desktop 3D printer which is operated using thermoplastic feedstocks.
However, not all possible emissions are covered by this method.  Many feedstocks could release hazardous emissions that are not measured by the chemical detectors prescribed in this document.  It is the responsibility of the user to understand the material being printed and the potential chemical emissions.  An example is PVC feedstocks that could potentially emit chlorinated compounds, which would not be measured by this document.

This document deals with the technical requirements and the means for their verification for AM machines using a bed of metallic powder and a laser herein designed as machine.
This document deals with all significant hazards, hazardous situations or hazardous events during all phases of the life of the machine (ISO 12100:2010, 5.4), as listed in Annex A, relevant to the applicable machine when it is used as intended and under conditions of misuse which are reasonably foreseeable
by the manufacturer.
This document does not deal with hazards which can occur:
— during construction;
— operating in potentially explosive atmospheres.
This document is not applicable to machines manufactured before the date of its publication

This document sets and defines the minimum requirements for registration of geometric data acquired from process-monitoring and for quality control in Additive Manufacturing (AM), including the description of a procedure.
Furthermore, this document comprises actions that users need to register multi-modal AM data and store them in an appropriate repository.
This document is not applicable for the following types of data: data cleansing, image processing, cost, production time and personnel.
This document in only applicable for geometric data gathered and generated from non-destructive test methods and sensors by using X-ray Computer Tomography (XCT), cameras and Coordinate Measuring Machines (CMM).
This document is only applicable to metals produced through means of Laser-based powder bed fusion (PBF-LB) and Direct Energy Deposition (DED).
Note: The procedure can be applied to monitor other AM processes and materials (e.g. polymer or ceramic power bed fusion, binder jetting, and photopolymerization), but this document does not provide any data or case studies for them.

This  document  defines  the  requirements  for  building  and  construction  projects  in  which  additive  manufacturing (AM) techniques are used. The requirements are independent of the material and printing method used.
This   document   specifies   the   criteria   for   additive   manufacturing   processes   and   quality-relevant characteristics and factors along the AM system operations and defines activities and sequences within an AM cell (Additive manufacturing site) and project.
This standard applies to all additive manufacturing technologies in building and construction (load bearing &  non-load  bearing),  structural  and  infrastructure  building  elements  for  residential  and  commercial  applications and follows an approach oriented to the manufacturing process..
Local H&S standards and environmental aspects are not covered in this standard but should be applied. Design approvals, material property characterisation and testing are are not covered in this standard.

This document specifies requirements for the additive manufacturing of metallic parts with directed energy deposition in the aerospace industry. These can be additively generated parts or additively generated additions to existing parts. Within the application scope of this document, wire is used as feedstock, and arc processes (gas-shielded metal arc processes, Tungsten inert gas processes, plasma arc processes) are the main energy source.
This document is to be used in conjunction with the engineering documents, if required by the engineering authority.

1.1 This practice describes the operation and production control of metal powder bed fusion (PBF) machines and processes to meet critical applications such as commercial aerospace components and medical implants. The requirements contained herein are applicable for production components and mechanical test specimens using powder bed fusion (PBF) with both laser and electron beams.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.
1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for the Development of International Standards, Guides and Recom-mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

This standard covers the test method for measuring hazardous substances emitted during the operation of material extrusion type 3D printer at the additive manufacturing public places and considerations for reducing hazardous substances like particle emissions (including ultrafine particle) and chemical substances (VOC, aldehydes)

This document defines the methodology for generic AM-machine evaluation in automotive
environment using objective test criteria and provides the framework for an objective AMmachine
evaluation and comparison. This document finds application in benchmarks,
preparation of purchase decisions, but also AM-machine evaluation within the machine
procurement, acceptance, and qualification process. The methodology and performance
characteristics are introduced to enable evaluation on an objective and quantitative basis. The
documentation resulting from the AM-machine evaluation is used to obtain a reliable orientation
selection and evaluation of PBF-LB/M AM-machines.
Furthermore, this document specifies machine KPIs in the context of machine procurement,
production planning and production of PBF-LB/M components. It aims to reach a detailed
understanding between machine supplier and machine customer with respect to the acceptance
criteria during the procurement process and evaluation of machine performance during running
production.
This document is applicable to the additive manufacturing technology LPBF-M defined in
ISO/ASTM 52900.

This ISO specifies personnel qualification requirements for manufacturing centres in which additive manufacturing processes are used.
This ISO defines general criteria for the qualification of machine operators, the activities and procedures regardless the process used in the part production

This ISO specifies personnel qualification requirements for manufacturing centres in which additive manufacturing processes are used.
This ISO defines general criteria for the qualification of machine operators, the activities and procedures regardless the process used in the part production.

This ISO specifies personnel qualification requirements for manufacturing centres in which additive
manufacturing processes are used.
This ISO defines general criteria for the qualification of machine operators, the activities and procedures regardless the process used in the part production

This document specifies requirements for the qualification of operators of laser metal powder bed fusion machines and equipment for additive manufacturing, except for aerospace applications. This document defines general criteria for the qualification of machine operators, the activities and procedures regardless the process used in the part production.
Note: Requirements for the qualification of operators of laser metal powder bed fusion machines and equipment for additive manufacturing in aerospace applications are addressed in ISO/ASTM 52942 Additive manufacturing — Qualification principles — Qualifying machine operators of laser metal powder bed fusion machines and equipment used in aerospace applications.

This ISO specifies personnel qualification requirements for manufacturing centres in which additive manufacturing processes are used.
This ISO defines general criteria for the qualification of machine operators, the activities and procedures regardless the process used in the part production.

This standard covers the qualification, quality assurance and post processing for metal parts made by laser powder bed fusion. This standard defines methods and procedures for testing and qualification of
various characteristics of additively manufactured metal parts, in accordance to ISO 17296-3:2013 Classes H and M. The standard is intended to be used by part providers and/or customers of parts. This standard is a top-level standard in the hierarchy of additive manufacturing standards in that it is intended to apply to metallic parts made by additive manufacturing. The standard defines qualification procedures and  acceptance criteria where appropriate to meet defined quality levels.

This Standard specifies personnel qualification requirements for industrial manufacturing centres regarding coordination of additive manufacturing (AM) production. The AM Coordinator is responsible for translating part requirements into manufacturing requirements such as:
- Assessing whether part information (likely beyond 3d file) is complete
- Assessing whether the part can be manufactured as specified and selecting appropriate
manufacturing processes.
- Managing the quality control aspects of manufacturing (e.g. route card)

This document defines the requirements for manufacturing centers, in which additive manufacturing methods are used (referred to below as additive manufacturing centers), which are independent of the material and manufacturing method used.
This document specifies criteria for additive manufacturing processes as well as quality-relevant characteristics and factors along the process chain and defines activities and sequences within an additive manufacturing center.
This document is applicable to the additive manufacturing technologies defined according to DIN EN
ISO/ASTM 52900 and follows an approach oriented to the manufacturing process.

This standard is aimed at providers of manufacturing services for polymer parts who use additive manufacturing machines and at the customers for these services. Designers of parts as well as buyers and providers of manufacturing services can specify, in a traceable manner, the required or the achievable level of quality with the aid of this standard. This standard applies to parts that have been manufactured from a thermoplastic polymer by means of laser sintering (LS) or material extrusion (MEX). Its applicability to other processes for polymers shall be checked in the specific case. The quality grades apply to parts that have not been post-processed after unpacking from the build space and the removal of possible support structures.

This guide will include post-process non-destructive testing of additive manufacturing (AM) of metallic parts with a comprehensive approach. It will cover several sectors and a similar framework can be applied to other materials (e.g. ceramics, polymers, etc.). In-process NDT and metrology standards will be referenced as they are being developed. This guide will present current standards capability to detect which of the Additive Manufacturing (AM) flaw types and which flaws require new standards, using a standard selection tool. NDT methods potential to detect AM flaws not covered by current standards will be recommended, and as new standards for flaws not covered by current standards are developed, they will be referenced in this standard via document updates.
This part of the International Standard:
⎯ Categorises AM defects
⎯ A review of relevant current standards
⎯ Enables suitable current standard NDT method/s to be used;
⎯ Details method specific to additive manufacturing and complex 3D geometries;
⎯ Outlines existing non-destructive testing techniques applicable to some AM types of defects;
This part of the International Standard is aimed at users and producers of additive
manufacturing processes. It applies wherever additive processes are used, and to the following fields in particular:
⎯ Safety critical applications;
⎯ Assured confidence in additive manufacturing;
⎯ Reverse engineered products manufactured by additively manufactured;
⎯ Test bodies wishing to compare requested and actual geometries.
NOTE Most metal inspection methods in NDT use ultrasound or X-rays, but these techniques cannot always cope with the complicated shapes typically produced by AM. In most circumstances X-ray computed tomography (CT) is a more suitable method, but it also has limitations and room for improvement or adaptation to AM, on top of being a costly method both in time and money.

Granular materials and fine powders are widely used in industrial applications. To control and optimize processing methods, these materials have to be precisely characterized. The characterization methods are related either to the properties of the grains (granulometry, morphology, chemical composition, ...) and to the behaviour of the bulk powder (flowability, density, blend stability, electrostatic properties, ...). The complex behaviours of granular and powder material has motivated the development of additional techniques to obtain reproducible and interpretable results. Many industries are concerned in different fields: additive manufacturing, food processing, pharmaceuticals, bulk material handling. The present technical report is focused on additive manufacturing. Metallic powders are widely used in Additive Manufacturing (AM) processes involving powder bed likepowder bed fusion (LBM, EBM, ...) or binder jetting. During such operations, successive thin layers of powderare created with a ruler or with a rotating cylinder. Each layer is then partially sintered or melted with an energy beam or glue with binder to build the parts. The layer thickness defines the vertical resolution of the printer; a thin layer leads to a better resolution. In order to obtain a thin layer, the powder is as fine as possible. However, as the grain size decreases, cohesiveness typically increases and spreadability, as defined within ASTM F42 / ISO/TC 261, is likely to decrease. The quality of the parts build with AM is thus directly influenced by powder flow properties.
Visual observation of layer homogeneity is usually the only way for operators to quantify the spreadability of powders  during  recoating. However, relating the powder characteristics to its spreadability during there coating process before hand should provide a more cost-effective way to classify and select the optimal powder and recoating speed combinations.
The aim of this technical report is to present an example of how the characterization of the macroscopic properties of metallic powders can be related to their spreadability inside LBM printers. A new technique combining measurements inside a LBM printer and image processing have been developed to quantify the homogeneity of the powder bed layers during recoating. Moreover, the flowability of four metal powders has been investigated with an automated rotating drum method, whose dynamic cohesive index measurement has been shown to correlate with the spreadability of the powder during the recoating  process.Furthemore, the PSD and morphology of each powder was characterized for each batch before testing bystatic image analysis method (ISO_13322-1_2014). The general principle of the study is presented on Figure 1