Press Release: With New Capabilities in Metal 3D Printing, PADT Expands its Presence in the AM Value Chain

The world of Additive Manufacturing continues to evolve, and PADT’s offerings grow with those changes. Our latest advance is in the addition of a new system and an experienced engineer – an EOS M 290 and Keng Hsu, former ASU and Univeristy of Lousville professor. Read below to learn more.

We also have a PDF and HTML version of the release.

As always, if you have any questions, please contact us.


With New Capabilities in Metal 3D Printing, PADT Expands its Presence in the AM Value Chain

To Deepen its Investments in Metal Additive Manufacturing Research and Development, PADT Also Brought Onboard Veteran Engineer Keng Hsu as Principal AM R&D Engineer

TEMPE, Ariz., November 17, 2020 PADT, a globally recognized provider of numerical simulation, product development, and 3D printing products and services, today announced it has installed an advanced metal 3D printer from EOS, a global leader in the industrial metal 3D printing technologies, at its headquarters facility in Tempe, Arizona. With this increase in AM process and material capability, PADT can not only develop the highest quality end-use metal products, but also is well-positioned to address some of the current research and development challenges in additive manufacturing. PADT’s wide range of customers in highly demanding industries, most notably aerospace and defense, will see direct benefits of this new capability.

To lead metal additive manufacturing research and development (R&D), PADT also announced it has brought onboard Keng Hsu, engineer, researcher and associate professor at University of Louisville and formerly Arizona State University. Hsu brings more than 20 years of experience in equipment and facility operations, engineering R&D, engineering project execution and management in areas of advanced manufacturing of polymers, metals, and semiconductors. He has performed in-depth R&D contracts on 3D printing process and material development for some of the world’s largest technology organizations including Intel, Northrup Grumman, Salt River Project, the Department of Defense, and NASA.

“Metal 3D printing has reached a level of maturity that enables the production of end-use components and is now one of the fastest-growing manufacturing sectors in the world,” said Rey Chu, co-founder and principal, PADT. “The addition of the powerful EOS M290 printer to our portfolio expands the already extensive list of 3D printing capabilities and services we offer our customers. Our investments in technology and the addition of additive manufacturing veteran Keng Hsu also improves our ability to perform in-depth R&D on the potential of metal 3D printing.”

Dr. Keng Hsu

The EOS M 290 is a highly productive, and well-established mid-size AM system with a broad portfolio of metals for production of high-quality components, and for material and process R&D. PADT will initially run two of the machines most popular and versatile metals – stainless steel and nickel super alloy. The system also features a host of software tools, including its comprehensive monitoring suite, which enables quality assurance of all production- and quality-relevant data in real-time. Hsu will lead PADT’s R&D involved with the EOS machine and all other aspects of the company’s work in 3D printing R&D and consulting.

“The innovation made possible by metal 3D printing and in the technology itself is yet to be fully realized across many industries, namely aerospace,” said Hsu. “I’m grateful for the opportunity to join a leader in the industry and further my research on the subject to advance PADT’s presence in the field and services for our customers.”

PADT has been the Southwest’s premier additive manufacturing expert since it was founded in 1994 and continues to invest in innovative metal and polymer 3D printing systems, as well as talent, to better serve its customers. The company is ITAR registered and its quality system is also AS9100D (2016) and ISO9001:2015 certified to better serve the aerospace and defense industry. As an Ansys Elite Channel partner, PADT can also bring their extensive simulation experience to better design parts to take advantage of laser powder bed fusion and to optimize the build processes itself.

As 3D printing technology has advanced, PADT has seen an increase in the industry’s use of 3D scanning and printing for end-use parts. Metal 3D printing provides many benefits to aerospace and defense companies, including lighter, cheaper parts made much faster and with fewer constraints than with traditional manufacturing methods.

A full list of the EOS M 290’s specifications can be found on PADT’s website here. For more information on PADT and its capabilities in metal and plastic 3D printing, please visit www.padtinc.com.

About PADT

PADT is an engineering product and services company that focuses on helping customers who develop physical products by providing Numerical Simulation, Product Development, and 3D Printing solutions. PADT’s worldwide reputation for technical excellence and experienced staff is based on its proven record of building long-term win-win partnerships with vendors and customers. Since its establishment in 1994, companies have relied on PADT because “We Make Innovation Work.” With over 90 employees, PADT services customers from its headquarters at the Arizona State University Research Park in Tempe, Arizona, and from offices in Torrance, California, Littleton, Colorado, Albuquerque, New Mexico, Austin, Texas, and Murray, Utah, as well as through staff members located around the country. More information on PADT can be found at www.PADTINC.com.

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Installing a Metal 3D Printer: Part 3A (Safety: Risks)

Download all 5 parts of this series as a single PDF here.

What are the safety risks in laser powder bed fusion metal 3D printing?

This is the first half of the 3rd post in a series of 5 on things we learned installing a metal 3D printer (laser powder bed fusion). Links to previous posts are below:

The most important discussions around installing and operating a metal 3D printer involve safety. The requirements can be difficult to pin down since they depend on several things: whether you are using reactive or non-reactive alloys (read a previous post on this subject here), the risk perception of your local building safety director and fire marshal, local regulations (and exceptions) and the volume of material you are dealing with. As with all things safety and more so because of how nascent metal 3D printing technology is, I list a few disclaimers at the bottom of this page.

There is so much to say about safety in this process that half-way through writing this post, it became clear it would not fit in one post. Therefore, I have split the content into two: in this post (3A) I talk about the risks: where they come from and why they matter. In the next post (3B), I will discuss how these risks can be mitigated.

1. Sources of Risk

Broadly speaking, I like to think of two sources of risk in this process since as an operator of these machines you have to think differently about how you interact with these sources.

1.1 Metal Powder

Metal 3D printing involves fusing together powder in a bed. Typical metal powders used for laser based 3D printing are spherical in shape and range from 10-70 microns in diameter, as shown in Figure 1. At this size, a metal can be prone to fire and explosion (under the right circumstances) and there is also the physiological concern of long-term inhalation of, and contact with, these powders. The powder also has a long life cycle and requires human interaction at many steps – from arriving in a container (as shown in Figure 2), through multiple recycling steps through final disposal. These risks come into play just when handling the powder (independent of its use in the process) – an additional risk comes from the melting process itself.

Fig 1. Typical powder particle size distribution is in the range of 10-70 microns for the laser powder bed fusion process.

Fig 2. Metal powders are delivered and stored in plastic containers such as the one shown above

1.2 The Laser Fusion Process

The powder in the bed described before is fused together into a solid using a laser that locally melts the powder one layer at a time. This is conducted in an inert atmosphere (Argon or Nitrogen) and is the second source of risk since these gases can displace Oxygen from a closed environment. Additionally, the process of laser melting of metals creates vaporized soot (see video below), some of which deposits on the process chamber and in the extraction module and filter. The smoke particles can be even finer than the powder itself, and need to be cleaned out with care on a regular basis.

2. Risks

There are 4 main risks arising from the laser powder bed fusion process: fire and explosion, powder inhalation and contact, inert gas asphyxiation and the environmental impact of the wastes generated.

2.1 Fire and Explosion

In May 2014, OSHA cited a 3D printing company for 10 violations deriving from the workplace safety standards surrounding the operation of a metal 3D printer (including not having the proper Class D fire extinguisher). The disregard of multiple safety measures during a routine build setup procedure resulted in a fire which caused life-threatening burns to the operator of the printer. While this incident was the result of gross negligence, it is nonetheless a cautionary tale that should drive us to understand the fundamental reasons why a metal 3D printer can cause fires and to appreciate the underlying reasons for why suppliers recommend the safety measures they do.

Fire and explosion require a combination of conditions as shown in the commonly cited image below used by OSHA and other agencies to communicate risks of powder handling.
As shown in Fig. 3, when handling powder in ambient atmospheres (with oxygen), all that is needed is a suitable ignition source to initiate a fire. Further, if this occurs in the presence of a dust cloud with many particles dispersed in a contained area (such as a small room or an air duct), this could lead to a more damaging explosion.

Fig 3. The oft cited fire triangle and explosion pentagon. Users of powder based metal 3D printing are often working with 2 of the 3 elements in the triangle and the key is to avoid the third.

  • Fire: When handling metal powder, the user needs to be aware that she/he already has 2 of the 3 requirements of a fire met and the main aim must be to ensure protection against any ignition source. There are several sources that could cause an ignition, the most likely one for a user of a metal 3D printer is static electricity. Additionally, it is possible that a fire can be initiated by hot surfaces, flames, hot gases and particles, mechanically generated sparks and strayelectrical currents.
  • Explosion: With regard to explosions, in addition to the 3 requirements above, dust clouds in contained areas can exacerbate any ignition to a much larger impact within milliseconds. Therefore, the prevention of the formation of metal dust clouds (as unlikely as that may seem), is of paramount importance.

In addition to the requirements above, there are levels associated with each requirement that need to be met together for an actual fire or explosion to occur. The risk of ignition increases with reducing particle diameter and given a certain particle size, the most significant factor governing risk is the nature of the metal. Reactive metals (Aluminum alloys, Titanium and its alloys, as well as smoke particles from both reactives and non-reactives) pose much higher risk than non-reactive metals (steels, Inconels, bronze, Cobalt Chrome alloys) – this is a subject I wrote about in more detail in a previous post.

2.2 Powder Inhalation & Contact

As discussed before, most metal 3D powder particles range in size from 10-70um. This is at the very edge of what is considered respirable and damaging to our lungs. While contact physically is to be avoided since it may initiate irritation and potential dermatitis, there is greater concern about the long-term inhalation exposure risks of these powders. Particles of the size range in this process can get deposited in the tracheo-bronchial region per Jenson [1] and Goldich [2]. Ultimately, these particles are discharged from the body or swallowed, but effects of long term exposure for the wide range of metals and alloys is not fully studied – which is why suppliers insist on respirators (more on that in the next post). It is worth pointing out though, from the work published by Jenson and Goldich, that it appears that while metal 3D printing powders are small enough to travel past the nasal cavity if inhaled, their sizes are large enough that respiratory damage in the lungs is highly unlikely – only particles under 2 microns are at risk of making it all the way to the alveoli and causing lung disease [2].

Fig 4. The human respiratory system. Particles in the 20-100 micron range, if inhaled, can make it to the trachea and bronchial regions [1, 2]  (Image Credit – public domain: National Institute of Health: National Heart, Lung and Blood Institute)

2.3 Inert Gas Asphyxiation

Inert gases are used in laser metal 3D printers to reduce the reactivity of the metal for processing purposes. Most metal 3D printers either use Nitrogen or Argon. Inert gas asphyxiation is the main risk due to oxygen being displaced by either of these gases that have leaked for some reason. Since both gases are not detectable by humans, victims do not realize that they are inhaling air depleted of oxygen and as a result this can have a serious impact. The human body is used to atmospheric percentages of oxygen (21%) and values below 19.5% can be harmful and are defined as oxygen-deficient per OSHA [3]. Thus, any user of nitrogen or argon gas (and this applies not just to any process using inert gases), especially in small spaces such as a closed room, needs to be aware of this risk and protect against it.

2.4 Environmental Impact

A key challenge with powder based processes lies in collecting and disposing the stray or “fugitive” powder from different locations such as the tool, PPE, containers and vacuum systems into temporary storage, during which the above risks of fire/explosion and inhalation remain. Additionally, the storage typically results in loose powder and solid waste as well as water with powder particles, both of which need to be disposed into the outside world and could pose an environmental hazard. I will discuss this further in a future post, when I attempt to look at some of the environmental aspects around this technology.

Fig 5. Metal powder settled at the bottom of the water column in the wet separator (vacuum cleaner). Where does it go next?

3. Disclaimers

  • This is intended to supplement the supplier training you must receive before using the equipment and not meant to replace it – in case of conflicting information, your supplier’s training and equipment requirements override any discussion here. PADT assumes no legal responsibilities for any decisions or actions taken by the readers of this document.
  • My personal experience derives specifically from the use of Laser-based metal 3D printing tools, specifically Concept Laser’s MLab Cusing R equipment. I expect majority of this information to be of use to users of other laser based powder bed fusion metal systems and to a lesser extent to Electron Beam systems, but have no personal experience to vouch for this.
  • Local, state and federal regulations vary, and are important – partner with your local fire marshal (or equivalent authority) as a starting point and take them along with you every step of the way. If in the US, familiarize yourself in particular with OSHA’s guidance on dust explosions [4] and NFPA 484 [5], the National Fire Protection Association’s standard for combustible metals (links below).

4. References

  1. J.M. Benson, “Safety considerations when handling metal powders,” Southern African Institute of Mining and Metallurgy, 2012
  2. R. G. Goldich, “Fundamentals of Particle Technology,” Chapter 15, Midland IT and Publishing, UK, 2002
  3. OSHA on Oxygen Deficiency
  4. OSHA’s Guidance on Dust Explosions
  5. National Fire Protection Association’s standard for combustible metals, NFPA 484
  6. D. Bhate, “Reactive and Non-Reactive Metal Alloys in Laser-based Powder Bed Fusion,” PADT Blog Post, 2016

Acknowledgements

Thank you to Perry Harlow-Leggett, the AM team at UL whose articles and webinars I have benefited from, and all the folks behind the scenes at OSHA and NFPA.

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Continue to Part 3B here, where I address mitigation strategies to address the risks described in this post. In the meantime, please read my prior posts below if you haven’t already, or send your inputs to me via message on LinkedIn. Thank you!

Major Milestone Achieved: 3D Printing of a Full Turbine Engine

3d-printed-jet-engine

Not long ago the sages in the additive manufacturing world said "Someday in the future we will be able to print a complete Turbine Engine."  That someday is now, much sooner than many of us predicted.  Researchers at Monash University in Australia recently created a modified version of a Safron Microturbo Auxiliary Power Unit using 3D Printing.  The whole thing.  Milestone Achieved.

The best article on this amazing story is on the Melbourne Examiner page:
www.smh.com.au/technology/sci-tech/3d-printing-melbourne-engineers-print-jet-engine-in-world-first-20150226-13pfv1.html 

Turbine Engines are really the peak of machine design. They contain every nasty thing you might run into in other machines, but spin faster and run hotter.  It's hard stuff. The geometry is difficult, lots of small features and holes, and significant assembly and tolerance constraints.  Getting a demonstrator built like this is a huge deal.  As a former turbine engine engineer and a long time user of additive manufacturing, I'm amazed. 

Check out their video:

The "3d Printer" they used was a huge Concept Laser Direct Laser Melting system.  The technology uses a laser to draw on the top of a bed of powder medal, melting the medal in small pools the bind and create a fully dense part with cast like properties.  They used three different metals: nickel alloy, titanium, and aluminum.

Concept-Laser-3d-printed-turbine-enginePADT has chosen to partner with Concept Laser for our metal 3D Printing strategy, which gives us additional excitement for this sucessful project.  

Now that someone has achieved this milestone, the industry can move forward with confidence that even more can be done with metal 3D Printing.  Much was learned in the creation of this advanced device that we can build on and apply to other industries and applications. 

Much is said in the twittersphere and press about printing food or custom dog tags, but this sort of high value industrial application is where the real impact of 3D Printing will be felt. It shows that companies can develop new more efficient products in less time and that are not constrained by traditional manufacturing methods.