ASTM B822-25 PDF

Full title and description

ASTM B822-25 — Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by Light Scattering. Specifies procedures for determining particle size distribution of metal powders and related compounds using light-scattering (laser diffraction) instruments, reporting distributions by volume percent and addressing dispersion media, deagglomeration, and instrument-related interpretation considerations.

Abstract

This test method defines how to measure particle size distributions of metal powders and related compounds using light scattering (laser diffraction) techniques. It covers sample preparation, dispersion (aqueous, nonaqueous, or gaseous), instrument assumptions and limitations, deagglomeration considerations, and reporting of results as volume percent over a recommended measurement range. The method is intended for use in product specification, manufacturing control, research, and lot-to-lot comparison.

General information

• Status: Active.
• Publication date: May 1, 2025 (newly published 2025 edition; ASTM record last updated June 18, 2025).
• Publisher: ASTM International (Committee B09 — Metal Powders and Metal Powder Products).
• ICS / categories: ICS 13.300 (technical classification commonly used for this standard within the Book of Standards listing).
• Edition / version: B822-25 (2025 edition), replaces ASTM B822-20.
• Number of pages: 5 pages (concise test method document).

Scope

This test method covers determination of particle size distribution by light scattering (laser diffraction) for particulate materials including metals and related compounds. It applies to analyses using aqueous, nonaqueous, or gaseous dispersions and is applicable to particle size measurement in the approximate range 0.4 μm to 2000 μm (or applicable subsets of that range). Units are SI; the standard does not address all safety concerns associated with handling powders.

Key topics and requirements

• Measurement principle: light scattering / laser diffraction and conversion models to particle size (reporting by volume percent).
• Applicable size range: nominally 0.4 μm to 2000 μm (instrument-dependent and subject to sample/dispersion specifics).
• Dispersion media: procedures for aqueous, nonaqueous, and gaseous dispersions, including guidance for hygroscopic or reactive powders.
• Sample preparation: deagglomeration and dispersion methods to obtain representative, reproducible measurements (note: associated ASTM practices address de‑agglomeration and sample handling).
• Limitations and interpretation: results depend on instrument models, optical assumptions (spherical-equivalent conversions), and sample shape — results from different methods/instruments are not directly interchangeable.
• Reporting and use: results reported as volume-percent distributions; intended for specification, process control, R&D, and lot comparison/acceptance testing.

Typical use and users

Used by powder suppliers, additive manufacturing and powder‑metallurgy manufacturers, quality control and testing laboratories, research and development groups, and procurement/acceptance testing teams to characterize powder feedstock and related compounds for processability (flow, packing), consistency, and specification compliance.

Related standards

Supersedes ASTM B822-20. Commonly used alongside other ASTM powder‑metallurgy standards such as B212, B213, B215, B527, B855 (de‑agglomeration practices), B923, and test methods for compositional analysis referenced in additive‑manufacturing test programs. It is consistent with international guidance on laser‑diffraction particle sizing such as ISO 13320 (Particle size analysis — Laser diffraction methods).

Keywords

particle size distribution, light scattering, laser diffraction, metal powders, powder metallurgy, additive manufacturing, deagglomeration, dispersion, volumetric distribution, ASTM B822-25

FAQ

Q: What is this standard?

A: ASTM B822-25 is a standard test method describing how to determine particle size distributions of metal powders and related compounds using light‑scattering (laser diffraction) instruments.

Q: What does it cover?

A: It covers sample dispersion (aqueous, nonaqueous, gaseous), instrument measurement and data conversion (reporting by volume percent), applicable size range (approximately 0.4–2000 μm), and guidance on sample preparation and interpretation of results.

Q: Who typically uses it?

A: Powder suppliers, AM/powder‑metallurgy manufacturers, QC/analytical laboratories, R&D teams, and procurement/acceptance testers who need standardized particle‑size data for specifications and process control.

Q: Is it current or superseded?

A: Current — the B822-25 (2025) edition is active and replaces the previous B822-20 edition.

Q: Is it part of a series?

A: It is part of ASTM Committee B09 (Metal Powders and Metal Powder Products) test methods and is commonly used with related ASTM powder‑metallurgy standards and test practices addressing density, flowability, sampling, deagglomeration, and chemical analysis.

Q: What are the key keywords?

A: Laser diffraction; light scattering; particle size distribution; metal powders; powder metallurgy; deagglomeration; dispersion; volumetric distribution; ASTM B822-25.