Overview
EN ISO/ASTM 52948:2026 establishes a comprehensive classification system for imperfections encountered during the powder bed fusion (PBF) additive manufacturing (AM) of metallic parts. Developed by CEN in collaboration with ISO and ASTM, this standard covers both PBF-LB (Laser Beam) and PBF-EB (Electron Beam) technologies, which are widely used in the production of high-performance metal components. It identifies the principal types of imperfections, discusses their probable causes, and provides visual representations to facilitate understanding and communication across the additive manufacturing industry.
This standard plays a key role in enhancing the reliability and repeatability of metal additive manufacturing by enabling standardized non-destructive and destructive testing practices. It does not specify acceptance criteria or dimensional tolerances, making it universally applicable as a classification and diagnostic tool for the detection and management of process-induced imperfections.
Key Topics
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Classification of Imperfections:
EN ISO/ASTM 52948 groups imperfections into six categories:
- Cracks
- Porosity
- Inclusions
- Lack of fusion
- Shape, dimensional, and surface imperfections
- Other types of imperfections
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Probable Causes of Imperfections:
For each imperfection type, the standard explains likely root causes, such as:
- Process parameters (e.g., laser power, layer thickness)
- Powder quality and contamination
- Equipment malfunction or calibration issues
- Build platform and support structure configuration
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Process-Specific Guidance:
While the focus is on PBF-LB and PBF-EB for metals, root cause analysis is tailored to these methods. Some guidance may be extended to other additive manufacturing processes, but users are advised that cause indications are process-specific.
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Visual Aids:
The inclusion of detailed illustrations and figures helps users identify imperfections and understand their orientation, position, and nature within a part.
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Terminology Alignment:
The document references internationally accepted vocabulary from related ISO and ASTM standards to promote harmonized understanding.
Applications
EN ISO/ASTM 52948:2026 is intended for a wide range of professionals involved with metal additive manufacturing, including:
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Quality Control and Inspection:
Standardized classification enables reliable non-destructive testing (NDT) and destructive testing (DT), supporting the detection and evaluation of process-related flaws.
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Process Development and Optimization:
Understanding and categorizing imperfections assists engineers and technicians in troubleshooting, parameter optimization, and continuous improvement of manufacturing processes.
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Supplier and Customer Communication:
The standard creates a common language for specifying part quality and reporting imperfection types, streamlining collaboration among manufacturers, suppliers, and end-users.
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Research and Standards Development:
A standardized imperfection taxonomy provides a foundation for further research, the development of acceptance criteria, and the improvement of additive manufacturing standards.
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Training and Education:
Visual examples and clear classification support workforce development, helping new practitioners in metal AM understand and mitigate typical manufacturing defects.
Related Standards
For comprehensive quality management in additive manufacturing, organizations should also consider the following relevant standards:
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ISO/ASTM 52900: Additive manufacturing - General principles - Fundamentals and vocabulary
Establishes foundational terminology used in the additive manufacturing sector.
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ISO 3252: Powder metallurgy - Vocabulary
Provides essential terminology for powder metallurgy processes.
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ASTM B243: Standard Terminology of Powder Metallurgy
Supports consistent language in powder-based metal processing.
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ISO/ASTM TR 52905: Additive manufacturing - Non-destructive testing
Offers guidance on NDT procedures for metal AM parts.
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ASTM E3166 & ASTM E3353: Standards for inspection and in-process monitoring of metal AM parts.
Summary
EN ISO/ASTM 52948:2026 is fundamental for manufacturers, inspectors, and researchers focusing on powder bed fusion additive manufacturing of metals. By enabling robust classification and understanding of manufacturing imperfections, it improves risk management, supports process optimization, and advances the overall maturity of metal additive manufacturing technologies. Adopting this standard helps ensure product quality, process consistency, and industry-wide alignment in defect classification and reporting.
