3D Metal Printing: Safety Challenges and Mitigation

April 6, 2017

John A. Slotwinski, Ph.D.

Additive Manufacturing Lead and Section SupervisorResearch and Exploratory Development Department

Johns Hopkins University Applied Physics Laboratory

Associate Research ProfessorDepartment of Materials Science and Engineering

Johns Hopkins University

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At APL We Take AM Safety Very Seriously…

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Outline

What is metal AM/3DP?What are the related hazards

and how do we mitigate them?What are the current safety

industry practices and standardization efforts? What are the lessons learned?

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Additive Manufacturing Center of Excellence

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Additive Manufacturing (aka 3DPrinting)

ASTM International: A process of joining materials to make objects from 3D model data, usually layer upon layer, as

opposed to subtractive manufacturing methodologies.

Synonyms: additive fabrication, additive processes, additive

techniques, additive layer manufacturing, layer

manufacturing, and freeform fabrication.

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Metal Laser Powder Bed Fusion

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What Are The Safety Hazards?

Fine Metal Powders Combustion Inhalation Skin Irritation Storage

Filtered Flammable Condensate High Power Laser Pressurized Inert Gasses and Oxygen

Displacement

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Metal AM Powders: The Basics

Types: Class A (Steels, Inconels, Cobalt Chrome,

Hastelloy) Class B (Aluminum, Titanium)

Produced primarily by Gas Atomization, provided by OEM or Third Parties

Generally spherical, diameters 10 m – 80 m

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Metal Powders: Safety

Hazards: Combustion Respiratory Skin Irritant Note: Powders generally not toxic

nor carcinogenic Mitigation:

Measurements Maintenance PPE Staying grounded Sparkless Tools Wet Separators to prevent powder

clouds Administrative

– Signage, training, approved operators only

Storage Note: Contrary to public

perception powders are generally contained!

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Other Hazards

Metal Condensate in Filters Class 4 Laser Inert Gasses

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Waste Disposal

Wet separator liquid waste Filters with solid condensate Trash

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The Things You Hope You Never Use…

Residue-free ABC extinguisher Class D fire extinguisher for metal

powder fires Eye Wash Gas exhaust system

In reality, the circumstances that would require these would be

extraordinary.

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AM Industry Safety Practice

There are no specific industry standards for metal AM.

Industrial safety implementation for metal AM runs the spectrum, from too much safety to not nearly enough.

Some previous metal powder standards are being applied, with good faith, but sometimes poor results.

Stay tuned, ASTM F42 is now developing AM safety standards.

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Conclusions and Lessons Learned

There are significant safety issues for metal powder AM but they are solvable

The first step to implementing metal AM, become friends with the organization’s safety officer

Be a jerk proactive about safety Safety is everyone’s responsibility With a new technology you sometimes have to make

judgment calls that are grounded in reasonableness

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Questions?