Designing Material Properties with Advanced Toolpath Generation
CDFAM Speaker Interview with Alex Roschli of ORNL
In this CDFAM Speaker Series interview, Alex Roschli, research staff member at Oak Ridge National Laboratory (ORNL) Manufacturing Demonstration Facility (MDF), discusses his background in robotics, the progression of his research, and the various aspects of his work on advanced toolpath generation for large scale additive manufacturing (AM).
Alex shares his insights on the challenges of materials and processes in additive manufacturing, as well as the potential applications and technology transfer of this process.
Alex will be presenting on Designing Material Properties with Advanced Toolpath Generation at CDFAM in NYC on day 2, June 15th.
Register now to attend CDFAM to lear more about Alex’s work at ORNL, and network with leading engineers, academics and developers working at the forefront of computational design and advanced manufacturing.
Could you please give us an insight into your role at ORNL, and share the journey of how your research in robotics played a significant part in leading you to this position?
I am currently a research staff member at Oak Ridge National Laboratory’s (ORNL) Manufacturing Demonstration Facility (MDF) in the Robotics and Intelligent Systems Group. I started at ORNL as a summer intern in May of 2012 after completing my freshman year of college in electrical engineering. I joined ORNL because of my interest in robotics and thought it to be a great place to learn. The group I joined was the Automatic, Robotics, and Manufacturing Group.
This group was transitioning to focus more heavily on manufacturing and 3D printing research but had a rich history developing robots and manipulators. I continued as an intern working in the summers and part time during the school year until I finished both my bachelor’s and master’s degrees in electrical engineering.
I joined as a full-time staff member in 2017. In my time at ORNL I’ve worked on projects such as the World’s First 3D Printed Car and the former World’s Largest 3D Printed Part.
With your background initially in software, motion control, and electronics, your move into large scale AM eventually encountered the challenges of materials and processes in manufacturing. How has your expertise in the digital domain helped you address and understand the physical aspects of manufacturing?
I started my research in additive manufacturing as a student, primarily operating new machines we were developing at ORNL. The initial machine and hardware development was handcuffed by limited software support, which ultimately spawned our software development efforts for slicing and toolpath generation.
In your upcoming CDFAM presentation titled “Designing Material Properties with Advanced Toolpath Generation,” you will discuss the transition from digital control to physical property manipulation. What main points or highlights do you plan to cover during your talk?
This presentation will highlight ongoing research on how slicing and toolpathing software can be used to manipulate print properties.
This will include changing material density based on simulation data within a layer, site-specific toolpath control, single path generation, and more.
In what ways do you believe the approach of defining material properties through toolpath control for large scale AM could be adapted to other processes, such as laser powder bed fusion?
A major advancement for large format AM is the ability to control material and printing properties within user defined regions of a layer.
This approach can be applied across multiple layers to define specific parameters for a tooling surface, such as higher resolution printing on the tooling surface and low resolution faster printing for the base structure. This same approach can be applied to powder bed systems to change melt pool parameters which allows for microstructure control.
Could you outline the software workflow used for defining, simulating, and validating parameters, material properties, and overall part performance?
Our process often starts with developing baseline material properties through a series of calibration prints.
The calibration prints can be used to create test coupons, such as tensile test dogbones. These can be used to start building a simulation model specific to the material and printing process. Printing parameters such as speed and temperature can be manipulated to collect additional data points to feed into the model.
More complex geometries can then be designed and simulated, then printed and tested against the model to continue improving the model.
The simulations can work from the CAD model to help the designer, but more robust simulation will work from the toolpath instructions to accurately simulate the entire building process.
What are some of the primary applications for which this process is being developed at ORNL, and how do you envision its transfer and adoption by the broader industry?
ORNL works directly with machine manufacturers, service bureaus, and end users to understand the pain points in the manufacturing market.
For those interested in adopting this process for their application, company, or industry, what key factors should they consider to determine their readiness for this technology or its potential to help solve specific engineering challenges?
Additive manufacturing as a whole is still a relatively new manufacturing process. Many organizations are working to qualify materials and develop the necessary standards, with the aerospace industry leading the charge and actively flying additively manufactured parts. Current research efforts are working to expedite the qualification process and lower the cost to help break into other industries.
Finally, considering the various applications, processes, and technology transfer aspects discussed earlier, what insights or collaborations are you looking forward to exploring during your participation at CDFAM?
ORNL has active research efforts in materials, processes, systems, and software development. We are seeking new partners to adopt and commercialize technology we develop, as well as new partners to approach us with research questions and manufacturing pain points.
At CDFAM, I’m hoping to learn more about how the industry validates and certifies end-use parts made with AM. I’m also always looking for toolpathing issues and limitations, and how we at ORNL can improve the state of the art with slicing software.