Metal additive manufacturing

In this Q&A session, Principal Optical Engineer Jason Karp describes how metal 3D printing and optical design combine to advance technologies.

Q: Digital manufacturing capabilities are a big part of Industry 4.0. How is metal 3D printing currently used in the industrial space?

A: Additive manufacturing took hold in rapid prototyping—it’s an inexpensive way to turn the crank very quickly and figure out what works and what doesn’t. Given our current digital environment, manufacturers today are looking not just to make prototypes, but to print fully functional components. Printing with materials like metal instead of plastic is helping this technology form components that are near-net shape and may just need post processing and finishing. It’s a pretty big change. 3D printing a part requires a broader understanding of the system it’s going into as well as the quality or regulatory standards of the system. There’s a huge push to try to figure out how to do that well.

Q: What role does metal additive manufacturing play in the aerospace and automotive industries, where lightweighting is especially important?

A: 3D printing has significant applications in aerospace, mostly because it’s one of the few industries that has a budget for metal 3D printing. Aerospace components must be lightweight and have good temperature stability and corrosion resistance, so nickel-based alloys, titanium, Inconel, and other unique alloys are all applicable here. There’s a push to develop 3D printed components at high-volume scale for the automotive industry, but the margins are much tighter, and the materials used are vastly different.

Additive manufacturing can be used to build seemingly impossible parts that you just can’t create using CNC or traditional subtractive manufacturing techniques. 3D printing allows you to make delicate parts with small internal passages or curves. This gives engineers some freedoms in terms of shape and design.

Part consolidation is another area of growth for 3D printing. You can take something that’s made of hundreds of nuts, bolts, and flanges and put it all together into one printed piece. It’s no longer an assembly, so you can shave out an enormous amount of weight as well as re-imagine your supply chain.

Q: Part consolidation sounds like a great application for 3D printing. But what are the drawbacks?

A: You must pick and choose where you use this technology. It’s a pretty slow manufacturing process and there really isn’t a good solution today to mix materials. Currently, 3D printing is a homogenous process, meaning all the material used to make a part—or group of parts—is the same. For example, your part can’t have steel in one place and aluminum or copper nickel in another. This can create headaches if certain parts have different functionalities requiring specific materials.

Q: Let’s talk about quality for a minute. How do optical design and machine learning play a role in 3D printing technology?

A: To get the right level of quality, you must consider the software, sensors, optical systems, and artificial intelligence to fully validate the process and understand where the underlying issues stem from. In laser printing, the optical systems are made up of lenses, mirrors, and scanners that selectively melt the material while cameras, photo diodes, and other sensors monitor in-situ signals that relate to quality.

Imagine you’re building a large part over the course of several days that can have tens of kilometers of cumulative welds. You’d want to monitor the building process to see if it’s going well or not because the last thing you want to do is go through this whole printing process and end up with quality issues. High-speed sensors can help detect issues — perhaps a lens is dirty, or you didn’t get a good spread of powder and the thickness is uneven. With this information, you can stop the build, flag the problem, and not waste additional resources.

Optical cameras, sensors, and filters can look at specific wavelength bands and try to identify signatures of what a good process looks like, what an anomalous process looks like, and what the different types of defects are that we might be able to identify.

Q: Where does Gray Optics fit in?

A: As an optics services company, we design components and systems that address processing and sensing needs. We can design lenses, simulate systems, fabricate components, identify filters, and put together the right pieces to enable a more productive system. We’re not inherently in the business of providing software around identifying whether a process is good or not, but we can provide the hardware or system improvements to support this.

Getting the right specifications requires domain knowledge about components and equipment. You need to pick the right cameras, photo diodes, fiber optics, or filters to design to the specs that ultimately produce the images you need. We also play an important role in assembly and industrialization. Instead of picking something from a catalog or cobbling pieces together, we can design and package a custom system in a compact, industry-ready format.

Partnering with Gray Optics can help you accelerate the design and development of your next project. Contact our engineers today.