Overview
EN 23923-2:1993 specifies the Scott volumeter method for the determination of the apparent density of metallic powders. This standard is applicable to metallic powders that do not flow freely through a 5 mm orifice, providing a reliable procedure for measuring apparent density without the flow issues encountered in other methods. While the oscillating funnel method (Part 3) offers better precision, the Scott volumeter method is preferred when vibration might alter powder properties during testing.
Developed under the guidance of ISO Technical Committee ISO/TC 119 (Powder Metallurgy), this standard ensures consistent and reproducible results critical for industries working with metallic powders.
Key Topics
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Scope and Applicability
- Designed for metallic powders unable to flow freely through small orifices.
- Suitable where vibration-sensitive powders must be tested without property alteration.
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Test Principle
- Apparent density is calculated by measuring the mass of a powder sample filling a known volume in a cup.
- The powder is introduced through a Scott volumeter’s series of inclined plates, cascading gently to fill the cup with minimum disturbance.
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Apparatus and Design
- Scott volumeter consisting of a funnel (with sieve), a baffle box with glass baffles to reduce powder velocity, and a stand.
- Cylindrical cup with a precise volume of 25 cm³ for consistent volumetric measurement.
- A balance accurate to 0.05 g for precise mass determination.
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Sampling
- Requires a minimum sample volume of 100 cm³ to allow triplicate testing.
- Powders are tested preferably in the as-received condition; drying instructions are specified if necessary.
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Test Procedure
- Powder is carefully poured into the funnel and passes through the sieve and baffles.
- Light brushing may be required to aid powder flow if not freely flowing.
- The cup is filled, leveled, tapped gently, and weighed.
- The test is performed three times to ensure accuracy.
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Result Expression
- Apparent density is determined by the formula:
Apparent density = mass of powder (g) ÷ volume of cup (cm³)
- Results are averaged and reported to the nearest 0.01 g/cm³.
- When variability exceeds 1% between tests, highest and lowest results must also be reported.
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Reporting Requirements
- Identification details of the powder sample.
- Reference to the EN 23923-2:1993 standard.
- Details of drying process if applied.
- Results with any deviations or incidents during testing.
Applications
This standard is essential for industries and laboratories involved in powder metallurgy, particularly:
- Manufacturing of metallic components by powder metallurgy, where accurate powder density impacts compaction and sintering processes.
- Quality control and assurance in production lines dealing with metallic powders of varying flow characteristics.
- Research and development in materials engineering to characterize novel metallic powders.
- Powder suppliers and distributors ensuring consistent product quality and specification compliance.
- Additive manufacturing processes, where powder characteristics affect layer deposition and final part quality.
By following EN 23923-2:1993, organizations optimize process control, improve product reliability, and ensure conformity with international standards.
Related Standards
- EN 23923-1:1993 (ISO 3923-1:1981) – Funnels method for apparent density determination of metallic powders that flow freely.
- EN 23923-3:1993 (ISO 3923-3:1982) – Oscillating funnel method providing better precision for apparent density but unsuitable for sensitive powders.
- ISO 3923 series – General guidelines and methods for determining the apparent density of metallic powders.
- ISO/TC 119 Technical Committee – Focuses on powder metallurgy standards and related test methods.
Using these complementary standards supports comprehensive evaluation of metallic powder characteristics across varying flow and testing conditions.
Keywords: Metallic powders, apparent density, Scott volumeter method, powder metallurgy, powder testing standards, EN 23923-2, ISO 3923-2, powder characterization, powder flow, volumetric analysis
