How Legacy Metal Additive Manufacturing Systems Are Failing the Aerospace Industry

by | July 6, 2021 | Business Drivers

If you’ve spent any time exploring the possibilities of metal additive manufacturing (AM) technology you’ve likely learned that it often falls short of expectations. This is especially troubling for those of you operating in the aerospace and defense industries, where design freedom, parts consistency, parts quality, and parts certification play a crucial role in determining successful outcomes.

Of course, if you’re lucky, you may have finally produced a 3D printed part that satisfies your needs, passes inspection, and has even been certified for flight, but it’s taken you more development time, design time, and expense than anticipated.  You’ve probably had to compromise your design once or twice to make it manufacturable, too.

Unfortunately, a common misconception is that metal AM hasn’t really evolved much in the last 30 years; that the technologies available today are simply one in the same. This couldn’t be further from the truth.

Before we get into how advanced metal AM like Velo3Dcan help you and your organization enter a new era of manufacturing by enabling you to build the parts you need without sacrificing design or quality—thereby helping you enter a new era of manufacturing—it’s important to first understand how legacy AM systems are stifling innovation and ultimately holding you back.

Most legacy systems do not provide a fully inert environment, frequently resulting in less-than-perfect results

When it comes to successful builds, the purity of the atmosphere that surrounds the workpiece during the printing process is critical. The injection of inert gases such as argon into the build chamber eliminates oxygen to reduce embrittlement and other undesirable metallurgical conditions.

This phenomenon is especially true with titanium and similarly reactive metals (alloys the aircraft industry prefers for their high strength-to-weight ratio), where oxygen and hydrogen can create higher porosity levels in parts.

Here’s the problem: legacy systems do a less-than-stellar job at atmosphere regulation, and some still allow a surprisingly large percentage of oxygen and humidity to remain present during a build, which results in less-than-perfect results showing up in the part.

Modulating inert gas flow to keep up with the soot that can accompany the lasing process is another challenge for legacy systems. Because they don’t optimally manage ventilation and flow of build-chamber gases during a build, any soot that’s produced during lasering, when not evacuated quickly enough, can interfere with energy delivered to the powder bed. That translates to inconsistent results and ultimately poor parts quality.

A solution that some legacy systems use is to pause the build process at the end of the layer to allow for the soot to clear; however, this dramatically impacts print speed.

Most legacy systems don’t monitor and record usable metrics layer by layer in real time

While some current systems claim to offer in-situ monitoring to detect some of these issues, in most cases this is mass data produced in a fashion that is not usable nor actionable. Imperfections can only be identified visually or through scanning after a print run is complete.

The recoater blade can also be an Achilles heel for many current metal AM systems

In most legacy AM systems, the floor of the build chamber contains a movable elevator platform that features a mounted metal build plate. The recoater blade then pulls the next layer of fine metal powder across the build plate and the fusion process repeats.

After each layer is complete, the elevator drops the build plate by a single-layer thickness, the recoater applies fresh powder across the surface, and the process continues until complete.

But as the part being printed overheats, protrusions occur, and when the protrusion reaches the height of the recoater (typically 20 to 40 microns), the rigid blade can collide with the part. and crashes the build.

Operators of many legacy systems remain locked into an expensive, time-consuming build-break-rebuild cycle

Because most systems can’t optimize build parameters for a specific part in advance, it often takes multiple builds to fine-tune a design and achieve final quality.

Not only is this inefficient and wasteful, but it also extends part lead times and adds unneeded cost to the production cycle.

Most legacy systems impose strict DfAM restrictions

With legacy AM systems, as the build angle decreases, the need for support structures to counteract the effects of stress increases. As a result, the need to design-in support structures increases and limits the geometries that are printable.

Simply put, legacy systems force designers and engineers to compromise their part design or manufacturability rather than optimal functionality and innovation.

The way forward with Velo3D advanced AM

So how can aerospace and defense engineers overcome the challenges inherent with legacy AM technology? By leveraging Velo3D’s end-to-end metal AM solutions, which feature the highest level of parameter definition, production mechanics, automated controls, and in-process metrology technology.

Our end-to-end metal additive manufacturing solution leap frogs the capabilities of legacy AM systems with new technology that enables engineers to build the parts they really need without compromising design or quality.

Velo3D’s unique end to end solution is a self-contained process that imports any CAD design, automatically applies intelligent print preparation recipes through our Velo3D Flow™ software which is then transported to a technologically advanced Velo3D Sapphire® additive printer that is being continually monitored and recorded in real time as the part is built layer by layer. This is done through our integrated Assure™ Quality Assurance and Control software that can also monitor many machines at the same time.

What’s more, Velo3D advanced metal AM opens a whole new world of design freedom thanks to its patented SupportFree™ metal additive manufacturing process.

With Velo3D SupportFree, angles down to zero degrees and other complex geometries and intricate internal features can be printed without compromise, giving designers and engineers an easier point of entry to adopting additive manufacturing.

We’re only scraping the surface here, and there’s much more to consider and learn.

For a detailed look at out how Velo3D advanced metal AM helps the aerospace and defense industries streamline and innovate, be sure to download our latest whitepaper:

Yes, You Can Achieve the Parts You Want with Additive Manufacturing

You can also contact us today to get the conversation started. 

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About the Author

Amir Iliaifar

Director of Content

Amir Iliaifar is the Director of Content at Velo3D where he oversees the production and distribution of Velo3D’s global digital content marketing initiatives. Prior to joining the company, Amir worked for a leading professional drone manufacturer, several SaaS companies, and as an automotive tech journalist. He holds a Master of Arts in Digital Communication from the University of North Carolina at Chapel Hill.