A Gas Atomization Primer

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If you're seeking consistent quality titanium powder for your additive manufacturing process, the issue may not be with the powder itself, but with the process used to produce it.

In our series, "A Clean Ti," we'll look at key sources of contamination for titanium and other pre-alloyed, gas atomized, spherical powders. Make no mistake: clean matters. Cross-contamination disrupts parts production in two key ways:

  1. Performance - If a part is going to fail it will always be at the point where contamination is present.
  2. Process Predictability - Even more importantly, suppliers must anticipate and alleviate contamination at the source or the powder supply can become unpredictable which can cost you time and money, and potentially customers.

The first step in understanding powder contamination risks is understanding the process used to produce it. We've made it as simple as possible in this brief primer.

4 Steps in Gas Atomization

Gas atomization is a robust technology for creating pure, free-flowing, pre-alloyed metal powder particles including titanium powders. First, the raw material is prepared for atomization in a plasma arc melter. This unit melts the powder into long bars or electrodes so they can be fed into the atomizer.

The electrode is placed in the atomizer and heated until molten metal drips off the end of the electrode until all but the end of the electrode is consumed. As the molten metal drips into the atomizer tower it is met by a stream of high-pressure, inert gas, typically argon or nitrogen.

The collision breaks the stream into into spherical powder particles that solidify in flight. The particles have the same chemistry as the molten stream, hence the term pre-alloyed.

4 Advantages of Gas Atomization

While it's important to understand and manage contamination risk in order to ensure consistent powder quality, gas atomization offers some important advantages over other pre-alloyed particle production:

  1. Chemistry Control: Gas atomization produces very pure powders that support extremely tight chemistry tolerances. That means they can be customized to satisfy stringent application requirements.
  2. Powder Morphology: Gas atomized powders are spherically shaped. Because they are free flowing they are ideal for additive manufacturing applications where powder flow is essential.
  3. Wide Particle Size Distribution (PSD): A wide PSD allows for high packing density, which maximizes the amount of powder in a given volume.
  4. Highly Flexible Capacity: Gas atomizers can produce a few pounds to several tons in a single heat with equal ease.

Want to learn more gas atomization? Check out our infographic and download our whitepaper.