Overview
ISO/ASTM 52925:2022 - "Additive manufacturing of polymers - Feedstock materials - Qualification of materials for laser‑based powder bed fusion of parts" provides guidance and recommendations for qualifying polymer powders used in laser‑based powder bed fusion of polymers (PBF‑LB/P). The standard focuses primarily on polyamide 12 (PA12) with references to polyamide 11 (PA11) and explicitly notes that its parameters are not applicable to other polymer families. It defines sampling, factory test reporting, and key material characteristics that affect processability and part quality.
Key technical topics and requirements
- Scope and material applicability: Guidance limited to PA12 (primary) and PA11; not a general polymer qualification standard.
- Sampling and representativeness: Procedures for representative sampling of virgin, blended and used powder - including homogenisation, blending, or taking multiple subsamples (e.g., at least five × 20 g if a mixer is not available).
- Factory test report: Batch‑specific measurements to be provided with every powder delivery. Minimum required data include:
- Particle size distribution (PSD) - D10, D50, D90 (volume/mass basis preferred). PSD influences spreadability, bulk density, surface finish and detail resolution.
- Residual monomer / extract content - minimise volatile monomers to prevent machine contamination and laser optic soiling.
- Supplementary data - certificates (SDS, RoHS/EU compliance), key additives/fillers/stabilisers declared where contractually agreed.
- Factors influencing processability:
- Powder spreadability, surface moisture / relative humidity, particle morphology and PSD.
- Bulk and tapped density (Hausner ratio) as indicators of flowability.
- Factors affecting part quality:
- Melting behavior, melt flow and MVR (melt volume‑flow rate), melting and recrystallisation temperatures; laboratory test methods (DSC, GPC referenced).
- Annexes provide methods and round‑robin data for MVR testing and Hausner ratio guidance.
Practical applications and users
Who uses ISO/ASTM 52925:2022:
- Powder manufacturers and material suppliers for batch certification and factory test reports.
- Additive manufacturing service bureaus and OEMs to qualify purchased powders and control incoming material quality.
- Process engineers and quality managers to set acceptance criteria for PBF‑LB/P production and to prevent machine contamination or degraded part performance.
- R&D teams evaluating PA12/PA11 formulations for PBF‑LB/P processability and part properties.
Practical benefits:
- Improved consistency of feedstock for reliable part density and mechanical performance.
- Reduced risk of laser optic soiling and machine downtime via residual monomer control.
- Clear specification of PSD and flowability metrics to optimise powder handling and layer spreading.
Related standards
- ISO/ASTM 52900 - Additive manufacturing - General principles - Fundamentals and vocabulary (referenced normative standard).
- ASTM D6779 - referenced as a possible specification call‑out for powder certification.
- Laboratory techniques referenced: DSC, GPC, MVR test methods (Annex B/C in the standard).
Keywords: ISO/ASTM 52925:2022, PBF‑LB/P, laser‑based powder bed fusion, PA12, PA11, powder qualification, particle size distribution, melt volume‑flow rate, additive manufacturing.