11 a.m. - 12 p.m. Location: ECSS 2.415
In this talk I will discuss additive manufacturing of nanotwinned metals at micro/nanoscale. Nanotwinned (nt) metals exhibit superior mechanical and electrical properties compared to their coarse-grained and nano-grained counterparts. nt-metals in film and bulk form are obtained using physical and chemical processes including pulsed electrodeposition, plastic deformation, recrystallization, phase transformation, and sputter deposition. However, currently, there is no process for 3D printing (AM) of nt-metals. Recently, for the first time, we demonstrated microscale 3D printing of nt-Cu with high density of coherent twin boundaries (TBs) using a new room temperature process based of localized pulsed electrodeposition (L-PED). The 3D printed nt-Cu is fully dense, with low to none impurities, and low microstructural defects, and without obvious interface between printed layers, which overall result in good mechanical and electrical properties, without any post-processing steps. The L-PED process enables direct 3D printing of layer-by-layer and complex 3D micro-scale nt-cu structures, which may find applications for fabrication of metamaterials, sensors, plasmonics, and MEMS and NEMS.
I will also talk about bioinspired composites. Many structural materials are quickly approaching their performance limits. There is an unmet demand for damage-tolerant, lightweight bulk structural composites for a range of applications including transportation, infrastructure, and for applications requiring operation in extreme environments, such as high temperature and high pressure. Damage tolerance refers to the ability of a material to exhibit simultaneous strength and toughness to resist propagation of cracks. In most engineering materials, with some exception, the strength and toughness are mutually exclusive, in a sense that achievement of optimal performance invariably imposes compromise. Biological composites achieve simultaneous strength and toughness through hierarchical architecture design. I will talk about our work on investigation of biocomposites and design and fabrication of bioinspired composites.
Majid Minary is an Assistant Professor in the Department of Mechanical Engineering at UT Dallas. He received his MS degree from University of Virginia in 2005, PhD from University of Illinois at Urbana-Champaign in 2010. He joined UT Dallas in 2012 after two years of Postdoctoral training at Northwestern University. He is the director of the UT Dallas Nano-Bio Lab. Current research interest in the group includes nanobiomechanics, additive nano/micro-manufacturing, and design, manufacturing, and characterization of bioinspired materials. The research in the group is supported by AFOSR-YIP, ONR-YIP, NSF and DOE.