Fine Metal Powder Classification for 3D Printing

Overview

Powder bed fusion printers are only as consistent as the powder they are fed. Metal powder producers serving the additive manufacturing (AM) market must deliver a tightly controlled particle size distribution, lot after lot, so builds behave the same every time.

TiERMAX supplies fine-powder classification systems for metal powder production. Each system pairs controlled feeding with high-efficiency screening to split powder into the fractions AM customers specify.

The Challenge

AM powders are extremely fine and difficult to classify. As mesh openings shrink, fine particles block the open area of the screen and separation becomes unstable. Surges in feed rate overload parts of the screen deck and make the problem worse.

The goal was accurate classification with stable screening conditions and minimal stops caused by difficult powder behavior.

The Solution

A multifrequency classification sieve was selected for the fine classification stage. It combines several vibration frequencies in one machine, keeping the screen surface active and promoting stratification, so fines reach the mesh and pass while oversize stays on top.

A controlled, continuous feeder upstream keeps the load on the screen even, which is critical for consistent classification. Deck count, mesh sizes, feed arrangement and machine size were selected from the powder characteristics, required fractions and production rate.

Equipment Supplied

Multifrequency vibrating sieve (MLT Cuccolini technology) providing:

• Fine metal powder classification and safety screening
• Mesh sizes down to about 10 µm, depending on the application
• One or two screening decks, depending on machine size
• Automatic mesh cleaning
• 304 or 316 stainless steel product-contact parts, mirror-polished where required
• Integration with controlled feeding equipment

Results

• More consistent particle size fractions
• Reliable removal of oversize material
• Better control of powder delivered to AM customers
• Fewer problems with fine-mesh blinding
• More stable screening conditions
• Flexibility to run different powder specifications

Off-spec fractions are routed to reprocessing instead of being mixed with finished powder. For similar projects, see our metal powder sieving and recovery systems.