Puris Discusses Titanium Powder Production and Near-Net Shape Titanium Parts for Additive Manufacturing

 

Puris, LLC, based in Bruceton Mills, West Virginia, USA, manufactures titanium powder for additive manufacturing. Puris claims to supply the cleanest titanium powder on the market. Recently, the company announced it had achieved a major milestone by additively manufacturing the largest, complex, 3D-printed titanium part for commercial use.

Puris, LLC
Bruceton Mills
West Virginia, USA

We caught up with Eric Bono, VP of Engineering Solutions of Puris, to learn about Puris, LLC in an exclusive AMazing® Q&A conversation.

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AMazing®: Eric, thank you for your participation. How long has the company been producing titanium powder for additive manufacturing? What are a few key competitive advantages that Puris holds with regard to titanium powder processing and ultimately, market adoption of titanium solutions?

Eric Bono: Thanks. We are pleased to participate. Powder has been produced here since 2012, but Puris began operating as a business entity in mid-2014. One of the strengths of our company is that it successfully brought together some of the world’s leading people, processes and technologies under one roof. Our facility houses a gas atomizer with a patent-pending all-titanium design.

In addition our technical team is led by Fred Yolton, whom I respectfully refer to as the godfather of titanium gas atomization; his contribution to advancements in the field have been significant enough to merit that accolade and more. He and the rest of our team of metallurgists and other experts joined Puris for one reason: to advance the field of titanium powder production specifically for additive manufacturing.

AMazing®: Puris recently announced a major milestone by additively manufacturing the largest, complex titanium part for a commercial application. How essential is powder cleanliness when additively manufacturing titanium parts that are highly complex, and at times, difficult to inspect?

Eric Bono: This is a topic about which we’re particularly passionate. In fact, we named the company Puris because of our core commitment to produce the cleanest powder possible. Contaminant-free powder is always critical because, as every first-year engineering student knows, a part will fail at the point of contamination.

Our titanium powder is used in high-performance applications including airplanes, aerospace components and people’s bodies where the threshold for contamination is zero.

You are correct in pointing out that inspecting powder to detect contamination is extremely difficult. A single chip of refractory can compromise a part, but might not be detectable through an inspection of sample lots of the powder. Instead we encourage manufacturers to assess the quality and integrity of the processes employed by their powder suppliers to eliminate contamination risk. Some of the things we recommend that customers assess include:

  1. Metallurgy expertise — A metallurgist can guide you about what characteristics are important and how they may impact your AM project, including oxygen pickup, flowability, powder distribution, tap density, apparent density and overall morphology.
  2. Atomization process — Not all gas atomization processes are created equal. Some use components that deteriorate during processing and must be replaced regularly to avoid contamination risk. A key advantage of our process is that the feedstock does not contact components in-process.
  3. Plant condition — Before committing your additive manufacturing projects to a titanium powder supplier it’s advisable to visit the plant and walk through the production process to assess contamination mitigation and safety standards.
  4. Range of powders produced — Multi-alloy production can create contamination risk in even the cleanest plant. It’s important that production is adequately segregated and properly ventilated as fine powder “migrates” easily.
  5. Safety processes — Handling powder is inherently hazardous, and the finer the titanium powder the more reactive it is. From production, blending and screening to shipping, safety must be a top priority.
19" x 19" x 11" with a .375 " cross-setion and approximately 31 lbs.  (Photo courtesy of Puris, LLC)

Additively manufactured titanium part produced using binder-jetting technology – 19″ x 19″ x 11″ with a .375 ” cross-section and approximately 31 lbs. (Photo courtesy of Puris, LLC)

AMazing®: What are a few known contaminants that can be introduced during titanium powder processing? What effects can these contaminants have on titanium material properties?

Eric Bono: Contamination can occur at any point in powder processing. We rely on our metallurgy expertise, advanced technology and rigorous processes to manage risk, including these four major risk areas.

  1. Raw material contamination. We produce our own electrodes whenever possible to ensure raw material integrity.
  2. Refractory. The presence of refractory in the nozzle or crucible area of the gas atomizer can present a contamination risk because it can chip off into the molten powder. Puris eliminated refractory from its gas atomizer in order to alleviate this risk.
  3. Iron Pickup. Stainless steel on the lining of the atomizer can lead to iron pickup. During processing hot powder that has not fully solidified when it impinges the sides of the atomizer may strip off small amounts of steel from the tower and piping. Puris eliminates the source of potential iron pickup with a patent-pending atomizer constructed with an all-titanium tower, cone, piping, cyclone and collection container.
  4. Cross-contamination. Each time an alloy change is made in the atomizer it introduces the risk of cross- contamination. Thorough cleaning processes are imperative to ensure all surfaces are clean. Puris follows stringent standard operating procedures (SOPs) to clean the atomizer and verify cleanliness that exceed industry-accepted standards.

AMazing®: Why is gas atomization ideal for producing titanium powder for additive manufacturing (AM)? What makes Puris’s titanium atomizer unique?

Eric Bono: There are three critical factors for AM powder: Flow-ability, oxygen levels and cost. While other processes deliver on some of these factors only gas atomization delivers on all three.

Gas atomization produces spherical powder, which flows better.

And gas atomization has less oxygen pickup during the production process. This is important in managing the oxygen levels for all titanium powder, but particularly for powder to be used in additive manufacturing. AM reuses powder, and each time powder is reused the oxygen level of the powder increases. Therefore the starting oxygen level of the powder is very important. The impact of our process on oxygen level is very predictable, which ensures the starting powder meets the specific application.

Finally we’re demonstrating the ability to use a wide particle size distribution (PSD) to produce parts. Fine powder represents a small percentage of powder produced, which makes it more costly. Efficacy of coarser powders benefits supply and cost.


Video courtesy of Puris, LLC

AMazing®: Many leading experts believe that in order for additive manufacturing to reach its full potential, there must be advances in materials, as well as design and process technologies. What advances do you feel are needed to additively manufacture large titanium parts on a production basis?

Eric Bono: We couldn’t agree more. In fact, we formed Puris with metallurgy experts specifically to understand and meet the needs of additive manufacturing. Our special focus and emerging expertise right now is on large part production. We’ve identified four areas for advancing large part production:

  1. Job box size. The printer box is the primary physical limitation on part size at present. Our ExOne M-Print 3D printer has the largest job box at 32″x20″x16″, yet our customers already want to explore even larger parts. In the near term we anticipate being able to meet that need by printing parts in segments and bonding them together during post processing.
  2. Non-destructive testing techniques. As parts become more complex we need the ability to test internal cavities without impacting the part’s integrity.
  3. Powder size. We believe it is crucial for coarse powder to demonstrate viability to meet market demands for supply, cost and safety. The large part we announced in January successfully used a wide particle size distribution (PSD), and our current development projects similarly use coarse powder.
  4. Education and time. There is no substitute for experience, and experience takes time. At Puris we are at the forefront of understanding powder needs for additive manufacturing. We are actively engaged in a number of large part development projects that will expand our knowledge base relative to size, complexity and materials.

AMazing®: What trends do you foresee with titanium powder processing?

Eric Bono: Specific to titanium powder processing we anticipate an increasing focus on flow characteristics vs. PSD. Historically PSD has been the driver of powder specs, but flow ability will become even more important.

Another important trend is and will remain physical property management, specifically, managing the impact of chemical changes that result from the AM process.

Finally, as the ability to print larger parts grows print time will become crucial. Presently our process is about six times faster than any other producer of large parts.Time becomes an important cost factor at production volumes.

This concludes our interview. Eric, thank you for your participation. We are very grateful for the opportunity to learn about Puris’s commitment to commercialization of titanium powder and near-net shape titanium parts for additive manufacturing.

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AM_Puris_E1JAbout Eric Bono:
Eric is vice president of engineering solutions for Puris, LLC. He leads business development for the company, leveraging his acumen with near-net shape titanium components from both a technical and development perspective. He brings 20 years of titanium processing expertise in rolling, extruding and manufacturing of metal powder; hot isostatic pressing and business development. Eric holds bachelor and master’s of science degrees in mechanical engineering (powder metal project) from University of Pittsburgh and an MBA from Carnegie Mellon University.

About Puris, LLC
Puris, LLC is among the world’s leading producers of titanium powder for additive manufacturing. The Puris team includes leaders in powder metallurgy and pioneers in spherical titanium powder gas atomization. The company’s innovative technology and processes promote the safe use of high-quality powder; available and affordable metal powder for aerospace, automotive, healthcare and oil and gas industries. Learn more at www.purisllc.com and follow us on Twitter (@PurisLLC) and Linked In. http://www.purisllc.com

Contact
Nanette Kirsch
Big Rock Marketing
724-316-5486
nanette@bigrockideas.com

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