EN ISO 10070:2019 PDF

Overview

EN ISO 10070:2019 - Metallic powders: Determination of envelope-specific surface area from measurements of the permeability to air of a powder bed under steady‑state flow conditions - defines a permeametry method to measure the air permeability, porosity, and derive the envelope‑specific surface area of metallic powders. The method uses a laminar air flow at near‑atmospheric pressure under steady‑state (constant pressure drop) conditions. This standard is intended for powder metallurgy applications and is published by CEN/ISO.

Key topics and technical requirements

• Measured quantities: air permeability of a packed powder bed, porosity, envelope‑specific surface area and (optionally) equivalent sphere diameter.
• Flow conditions: steady‑state laminar flow (constant pressure drop); constant volume methods are excluded.
• Applicable powders: all metallic powders (including hardmetals) up to 1 000 µm diameter, commonly used for particles 0.2–75.0 µm. Not intended for highly non‑equiaxial shapes (flakes, fibres) unless agreed by parties.
• Limitations: not applicable to mixtures of different metallic powders or powders containing binders or lubricants. Measured surface area is the envelope surface (excludes closed/blind pores) and can differ from gas‑adsorption total surface area.
• Formulations and models: the standard discusses permeability–porosity relationships (e.g., Carman‑Arnell and Kozeny‑Carman formulations) and the assumptions that affect calculated surface area.
• Annexes and methods: informative Annex A describes practical implementations - Lea & Nurse, Zhang Ruifu and Gooden & Smith methods (Gooden & Smith now includes an automated/commercial device in the 2019 edition). Annex B covers de‑agglomeration treatments and their effect on results.
• Reporting: specifies test preparation, packed bed formation, measurement procedure, expression of results and required test report details. ISO 3954 (sampling) is referenced for sample selection.

Applications and users

• Who uses it: powder manufacturers, quality control laboratories, research & development teams in powder metallurgy, sintered component producers, and suppliers of powder testing equipment. It is also relevant for additive manufacturing and hardmetal production where powder surface area and flow/packing behavior affect processing.
• Practical uses: characterizing powder flow/permeability for process control, comparing batches, converting envelope surface area to equivalent particle size for specification, verifying de‑agglomeration effects, and calibrating permeametry instruments.

Related standards

• ISO 3954 (Powders for powder metallurgical purposes - Sampling) - normative reference cited in EN ISO 10070:2019.

Keywords: EN ISO 10070:2019, metallic powders, envelope-specific surface area, permeability to air, powder bed, steady-state flow, permeametry, Carman-Kozeny, de-agglomeration, powder metallurgy.