#325 Granular Copper

325 Mesh Fine Powder Consistent Particle Distribution High Surface Area Production Supply Form

High-purity 325 mesh granular copper powder in standard packaging for powder metallurgy, friction materials, conductive inks, and industrial applications.

Solidus

1,984°F (1,084°C)

Liquidus

1,984°F (1,084°C)

Primary Elements

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Product Overview

325 Granular Copper 325 Mesh Powder is a high-purity copper powder atomized to 325 mesh size supplied in standard unit packaging for industrial powder metallurgy and specialty manufacturing applications. The reddish-pink granular powder has excellent flowability and consistent particle size distribution for reliable performance in automated powder processing and paste formulation equipment. This product is the standard supply form for production quantities of 325 mesh copper powder serving powder metallurgy part manufacturers, friction material producers, conductive ink and paste formulators, and diamond tool manufacturers. The consistent particle size distribution and apparent density from batch to batch are critical for maintaining process consistency in automated pressing, sintering, and paste formulation operations. The high surface area of 325 mesh powder relative to coarser grades provides faster sintering kinetics and more uniform paste rheology making this the specification of choice for applications requiring dense uniform microstructure in the finished product.

Available Forms

325 Mesh Powder

Product Code

4307A

Technical Info

Thermal Properties

Melting Point (Solidus)1984

Melting Point (Liquidus)1984

Physical Properties

Primary ElementsCu

Performance tags

325 Mesh Fine PowderConsistent Particle DistributionHigh Surface AreaProduction Supply Form

Frequently Asked Questions

Common technical inquiries regarding #325 Granular Copper

Key quality parameters include: particle size distribution (d10, d50, d90 by laser diffraction); apparent density (2.4-3.2 g/cm3 is typical — tighter control improves die fill consistency); purity (minimum 99.5% Cu for most applications — verify by ICP or OES analysis); and oxygen content (below 0.3% for standard applications and below 0.1% for high-conductivity parts where oxygen reduces sintered conductivity). Request a certificate of analysis with each lot and establish incoming QC protocols to verify these parameters.

325 mesh copper powder provides better ink and paste performance than coarser grades for most printed electronics applications: finer particle size reduces settling in the ink vehicle, enables thinner line printing without particle bridging or clogging fine screen openings, and produces smoother denser printed conductor tracks after firing. The higher surface area also improves reactivity with flux components in the paste improving sintering of the printed conductor at lower temperatures.

Copper powder is sintered in a reducing atmosphere — typically hydrogen, a hydrogen-nitrogen forming gas mix, or dissociated ammonia — at temperatures of 1650-1850F for 30-60 minutes depending on part geometry and target density. The reducing atmosphere prevents oxidation of the copper powder surface during sintering which would inhibit the diffusion bonding between particles that produces density and strength. Sintering in air or nitrogen alone is not recommended — the resulting oxide layer produces porous weak parts with poor conductivity.