6 Things You Might Not Know about Making Metal Parts through Additive Manufacturing
Let go of the notion of simply “printing” a part. That is, let go of the notion that you can just press a button and the part will be created—additive manufacturing is not like that. Instead, AM is a process with important process considerations all its own. Particularly where metal parts are concerned, these considerations need to be understood in order to realize the benefits that AM can deliver.
I recently spoke about this with AM researchers at Penn State University’s CIMP-3D facility. Find a detailed article at the link below. Here are important points worth knowing if you are considering AM for metal part production:
- New design tools might be needed. Metal parts being made today were designed for casting, forging and/or machining. Additive manufacturing opens the way to complex, mathematically streamlined component forms that a CAD designer’s typical tools would not be able to create. Software for topology optimization becomes important.
- There is still plenty of scrap. Support structures are part of the engineering of an additive build. These structures (see photo) consume not only a share of material, but also perhaps a large share of the cycle time for the part.
- Orientation has an impact. Do you build a given part so that it lies on its side? Sticks up vertically? Leans at a 45-degree angle? This decision—how to orient the part for its AM build—has a significant effect on part accuracy, cycle time and where the support structure is needed.
- Residual stress is the hidden challenge. Internal forces can deform an additive part as layers are added and the part cools. Sometimes, trial-and-error is needed to find the process for a given part that will overcome this effect.
- Material changes with use. Some particles melt before others. As a result, powder left over from a build has slightly different particle distribution from the powder that began it, and thus different properties. AM powder changes over time to a much greater extent than other manufacturing material stock.
- Your new lightweight metal might be titanium. Titanium alloys are well-understood in additive manufacturing and therefore easy to apply. This tends to make titanium the AM metal of choice. Indeed, because of its high strength-to-weight ratio, a part redesigned for weight savings through AM might be lighter in titanium than it was when it had been a thick, solid part in aluminum that was designed for a more conventional process.
When your metal part is done 3D printing, you just pull it out of the machine and start using it, right? Not even close.
A bracket redesign has a lot to say about the successful application of metal AM. One of the takeaways: Support structures are worth the effort!
Lincoln Electric Additive Solutions’ robotic metal 3D printing process is a choreographed dance between welding, robots, automation, heat management and machining. The new venture may have a distinct advantage in the field: its parent company’s 125 year-old legacy.