Precision control of 3D printing of metals at specific microscale locations and crystal-structure orientations

October 16, 2014

ORNL researchers have demonstrated the ability to precisely control the structure and properties of 3D-printed metal parts during formation. This electron backscatter diffraction image shows variations in crystallographic orientation in a nickel-based component, achieved by controlling the 3D printing process at the microscale. (Credit: ORNL)

Researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) have demonstrated a additive manufacturing method for controlling the structure and properties of metal components at the microscale with precision unmatched by conventional manufacturing processes.

“We can now control local material properties, which will change the future of how we engineer metallic components,” said Ryan Dehoff, staff scientist and metal additive manufacturing lead at the Department of Energy’s Manufacturing Demonstration Facility at ORNL.

“This new manufacturing method will …  help us make parts that are stronger, lighter, and [that] function better for more energy-efficient transportation and energy production applications such as cars and wind turbines.”

Achieving microstructural variability in a single build (credit: ONRL)

The researchers demonstrated the method using an ARCAM electron beam melting system (EBM), in which successive layers of a metal powder are fused together by an electron beam into a three-dimensional product.

By manipulating the process to precisely manage the solidification on a microscopic scale, the researchers demonstrated 3-dimensional control of the microstructure, or crystallographic texture, of a nickel-based part during formation.

Crystallographic texture plays an important role in determining a material’s physical and mechanical properties.  Applications from microelectronics to high-temperature jet engine components rely on tailoring of crystallographic texture to achieve desired performance characteristics.

“We’re using well established metallurgical phenomena, but we’ve never been able to control the processes well enough to take advantage of them at this scale and at this level of detail,” said Suresh Babu, the University of Tennessee-ORNL Governor’s Chair for Advanced Manufacturing. “As a result of our work, designers can now specify location specific crystal structure orientations in a part.”

Dehoff presented the research this week in an invited presentation at the Materials Science & Technology 2014 conference in Pittsburgh (downloadable here).

Other contributors to the research are ORNL’s Mike Kirka and Hassina Bilheux, University of California Berkeley’s Anton Tremsin, and Texas A&M University’s William Sames.

The research was supported by the Advanced Manufacturing Office in DOE’s Office of Energy Efficiency and Renewable Energy.