Fine Metal Powder Classification for 3D Printing

Overview

Metal powder quality is a critical part of additive manufacturing. Before powder reaches the 3D-printing process, its particle-size distribution must be controlled to ensure that the required fraction is consistently supplied to the next production stage.

TIERMAX provides fine-powder classification solutions for metal powder production, combining controlled feeding with high-efficiency screening technology to separate powders into the required particle-size fractions.

Challenge

Metal powders used in additive manufacturing can be extremely fine and challenging to classify.

As mesh openings become smaller, fine particles can reduce the effective open area of the screen and make consistent separation increasingly difficult. Variations in feed rate can create additional problems by overloading portions of the screening surface.

The challenge is therefore to achieve accurate classification while maintaining stable screening conditions and minimizing interruptions caused by difficult powder behavior.

Solution

A multifrequency screening system provides the required fine-powder classification stage.

The screening technology combines different vibration frequencies within the same machine. This keeps the screening surface active and promotes particle stratification, helping fine particles reach and pass through the selected mesh while oversized material remains above it.

Controlled and continuous feeding can also be incorporated upstream of the screener. Maintaining a stable powder feed is particularly important for classification because excessive or irregular loading can reduce separation efficiency.

The number of decks, mesh sizes, feeding arrangement and machine configuration are selected based on the powder characteristics, required fractions and production capacity.

Equipment

Multifrequency Vibrating Sieve – MLT Cuccolini

The system can provide:

• Fine metal-powder classification
• Safety screening and classification
• Mesh sizes down to approximately 10 μm depending on application
• One or two screening decks depending on machine size
• Automatic mesh cleaning
• AISI 304 or 316 stainless-steel product-contact parts
• Mirror-polished internal finish where required
• Integration with controlled feeding equipment

Results

Integrating fine classification into the metal-powder production process helps provide:

• More consistent particle-size fractions
• Effective separation of oversized material
• Better control of powder supplied to the additive-manufacturing process
• Reduced problems associated with fine-mesh blinding
• More stable screening conditions
• Greater flexibility in managing different powder specifications

Out-of-specification fractions can also be directed to the appropriate downstream or reprocessing route rather than being mixed with the finished powder.