Powder Analysis and Manufacturing with Microtrac, ATO Lab Plus & AO Metal – July 2025

Powder analysis for metal additive manufacturing

In powder-bed metal 3D printing, the powder is the process. Particle size distribution and particle shape control how a layer spreads, how densely it packs, and how consistently it melts under the laser. When the feedstock drifts out of spec, the result shows up downstream as porosity, poor surface finish, and scatter in mechanical properties. Characterizing the powder before and after each build is the most direct way to keep an additive process stable.

This article looks at how the Microtrac CAMSIZER X2+ measures particle size and shape for metal powders, why dynamic image analysis captures information that laser diffraction misses, and where that data matters most for laser powder bed fusion (LPBF) and metal injection molding.

Why particle size and shape matter for LPBF

Metal AM powders are engineered to a narrow size window, typically dominated by spherical particles that flow and pack well. Two properties drive print quality:

• Particle size distribution (PSD) — controls packing density, spreadability, and how evenly the layer melts. Too many fines can cluster and disturb recoating; too many oversized or fused particles create defects.
• Particle shape (morphology) — spherical particles flow uniformly, while irregular, satellite, or elongated particles reduce flowability and packing. Shape changes as powder is reused, so it needs to be tracked, not assumed.

Because size and shape both shift over a powder’s service life, measuring only one number does not describe the material well enough for a demanding metal process.

The importance of particle analysis with the CAMSIZER X2

Raw powder cost is a significant factor in metal AM. Only a small fraction of the powder bed is sintered into the part; the rest, left unsintered, is recycled. That recycled material can carry an unwanted amount of oversized, fused particles, and the shape of individual particles can differ from the original powder. In practice the recycled powder often needs to be screened to remove oversized particles and blended with fresh powder, which makes verifying the quality of recycled powder essential.

The CAMSIZER X2 measures both particle size and particle shape, characterizing the feedstock comprehensively. Because it detects individual particles, even the smallest amounts (below 0.01% by volume) of out-of-spec particles are found. That sensitivity keeps the quality of the printed parts consistent from build to build.

For metal powders the recommended approach is dry dispersion with the X-Jet module at a moderate dispersion pressure of 20 kPa. The X-Jet module disperses the sample effectively but gently, and the particles are measured in an air flow.

What metal powders can be analyzed with the CAMSIZER X2

The CAMSIZER X2 handles the metal powders common in additive manufacturing and powder metallurgy, including aluminum, cobalt, chromium, Inconel, manganese, molybdenum, nickel, steel, titanium, tungsten, silver, gold, and their respective alloys. For most of these, dry dispersion with the X-Jet module at 20 kPa gives reliable, repeatable results.

Dynamic image analysis versus laser diffraction

Historically, particle size analysis of metal powders was done by sieve analysis or laser diffraction. Dynamic image analysis (DIA) gives a fuller picture of material properties because it detects the length and width of each particle independently, while laser diffraction reports only a single “size” parameter.

Laser diffraction algorithms, regardless of brand or model, are based on a simple sphere model. The real particle shape is ignored and only an “equivalent diameter” is calculated. For irregularly shaped particles, laser analyzers often mix particle length and diameter data, which overestimates the proportion of large particles and suggests a wider size distribution than the powder actually has.

The CAMSIZER X2 works differently. It captures thousands of images per measurement and evaluates individual particles, so oversized material below 0.01% by volume is reliably detected. If a particle is captured, its data is included in the result, even if only a single particle of that size and shape exists in the sample — the “needle in a haystack” case.

A laser diffraction analyzer, by contrast, detects an averaged scattering signal from all particles at once. Small quantities of oversize or undersize particles are only reflected in the result once they exceed the detection limit, typically around 2% by volume. Below that threshold the signal is treated as noise and ignored, so a laser analyzer does not detect oversized particles reliably. Both sieve analysis and the CAMSIZER X2 offer much better sensitivity.

In side-by-side data, the CAMSIZER X2 reports particle width, particle length, and the equivalent circle diameter. The x50 of the equivalent circle diameter is usually close to the laser analyzer’s result, and the percentage of oversize particles measured by the CAMSIZER X2 agrees closely with sieve analysis, whereas the laser sizer calculates too many large particles relative to sieve results.

Reproducibility with titanium and steel powder

Titanium powder is used in applications such as aerospace. In one example, two powders with different size distributions were measured using the X-Jet dry dispersion module at 20 kPa. Each steel powder measurement took less than 20 seconds, and the four repeat curves overlap almost perfectly, showing excellent reproducibility. The two titanium powder measurements behave the same way and agree closely with sieve results. Across both materials, the CAMSIZER X2 shows strong agreement with sieve analysis.

Fine powders for metal injection molding

Even near its lower detection limit of about 1 μm, the CAMSIZER X2 offers better resolution and sensitivity than a laser particle sizer. These fine powders are typical of metal injection molding (MIM). In one example, two fine metal powders with d50 values of 4.5 μm and 5.2 μm were measured in dry dispersion mode, with the CAMSIZER X2 resolving powders down to 1 μm with good resolution, repeatability, and sensitivity.

Putting the data to work in additive manufacturing

The CAMSIZER X2 is well suited to determining the particle shape and size distribution of fine metal powders. In powder metallurgical processes such as additive manufacturing, dynamic image analysis provides useful information about the usability of both raw and recycled material. The short measuring times, high sample throughput, reliable detection of even small amounts of oversize, and identification of particles that deviate from the target shape make it practical for routine incoming inspection and powder-reuse checks.

Particle characterization is one part of a larger metal AM workflow that runs from atomization and powder supply through printing. Additive Plus brings more than 10 years of experience helping customers integrate and optimize additive manufacturing, with a portfolio that includes brands such as Farsoon Technologies and Kings3D and support that spans design through consulting.

To go deeper on the surrounding topics, see our guide to using the CAMSIZER for strong 3D prints and our complete guide to metal printing with powder. You can also browse our metal powders and atomizers in the catalog.