Researchers at Oak Ridge National Laboratory, Oak Ridge, Tenn., have demonstrated that building parts by electron beam melting enables control of the microstructure and properties of metal components with high precision. Dr. Ryan Dehoff, staff scientist at ORNL, presented the research results last week in an invited presentation at the Materials Science & Technology 2014 conference in Pittsburgh. The researchers demonstrated the method using an ARCAM electron beam melting system in which successive layers of a nickel-base powder were fused together by an electron beam into a three-dimensional product.
By manipulating the process to precisely manage solidification on a microscopic scale, the researchers demonstrated 3-dimensional control of the microstructure 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 required d performance characteristics.
“We can now control local material properties, which will change the future of how we engineer metallic components,” Dr. Dehoff said. “This new manufacturing method takes us from reactive design to proactive design. It will help us make parts that are stronger and lighter, and that function better for more energy-efficient transportation and energy-production applications such as cars and wind turbines.”
“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.”
