3D Printing Multiple Metals in a Single Complex Structure: Guhaprasanna “Guha” Manogharan and his team at Penn State College of Engineering and the Center for Innovative Materials Processing through Direct Digital Deposition (CIMP-3D) have developed a method to 3D print complex parts with different materials to achieve multiple design and engineering goals.

Tech Briefs: What got you started on this project?

Guhaprasanna “Guha” Manogharan: I've been involved in advanced manufacturing as a user, researcher, and educator for a long time, and I always try to have a balance of fundamental research and applied research. So, in my group, we are working on fundamental research questions that would solve a problem an end user could implement in the next three to five years.

I've been involved in additive manufacturing for the last 20 years or so, since the time it used to be called rapid prototyping. In the early years, it was only developed for prototyping purposes. Typically, it was with polymers; then metal additive manufacturing came along. It has been helped by serious investments from the government through institutes such as America Makes, DoD, DoE, and NSF, and it's come a long way.

One particular area of interest for any engineer — mechanical, materials, civil, biomedical — is the tug of war between getting the right properties through the manufacturing process vs. the inherent properties of the material. For example, whether you're printing with aluminum vs. steel or nickel, or using stamping or any other manufacturing process.

For the last several years, there has been a concept called functionally graded material. It's often laser-based powder cladding, where you gradually go from 100 percent of alloy A to 100 percent of alloy B by grading the material function. For example, you can print a material that is very strong, but then you can gradually add a corrosion-resistant material on the outside surfaces. You can think of that method as being like laser welding, but instead of using one uniform material as your feed, you change the material as you go. But, you cannot produce the final part without a lot of post-processing — you cannot get anything that has really fine detail.

So, what got us started in this research direction is this tug of war between materials and design freedom.

Directed energy deposition is an existing process in which a laser or plasma serves as an energy source, and you simultaneously deliver powder at the same time....