University of Massachusetts Amherst

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MIE Seminar Series: Translating processing-property-microstructure relations to additive manufactured materials


Monday, March 27, 2017 - 10:15am


Dr. Kelvin Xie, Johns Hopkins University


Kellogg Room, Elab II


Throughout history, new manufacturing methods have vastly improved the scalability and practicality of groundbreaking technologies. With the advent of additive manufacturing, a new avenue has been opened to fabricate components with complex geometries. However, nano-scale microstructure of 3D printed materials is not as well understood as the conventionally manufactured counterparts. Lessons learned from strengthening mechanisms in traditionally processed materials can be implemented in 3D-printed components. One example is solute cluster strengthening in a high-strength low-alloy steel: a fine dispersion of atomic clusters (40 atoms in size) resulted in a ~35% increase in strength without sacrificing ductility. Another example is nano-twin hardening in boron carbide: incorporating high-density nano-twins led to ~10% harder boron carbide plates without reducing fracture toughness. The 3D printing community, to date, has primarily focused on characterization at the granular level, using low-resolution SEM-based techniques. Here, we propose a more fundamental investigation into the nano-scale of additive manufactured components using state-of-the-art transmission electron microscopy and atom probe tomography. This insight can lead to novel materials-by-design strategies, incorporating nano-scale features to understand and improve the mechanical properties of 3D-printed materials.

Dr. Kelvin Xie is an Assistant Research Scientist working with Prof. Kevin Hemker at Johns Hopkins University. He obtained his Ph.D. at the Australian Centre for Microscopy and Microanalysis under the supervision of Profs. Julie Cairney and Simon Ringers. Kelvin’s research interest is to fabricate (e.g. via additive manufecturing) and characterize strong and lightweight materials (e.g. B-based compounds, Ti alloys, etc.) by atomic-level understanding of their microstructure and deformation mechanisms.