188. EXPLORATION OF GRAIN SIZE EFFECT, TEXTURE DEVELOPMENT AND AGING EFFECT ON SUPERELASTIC FERROUS-BASED ALLOYS
Research Institute Affiliation: Graduate Program in Materials Science and Engineering
Faculty Advisor(s): Kenneth S. Vecchio
Name: Cheng Zhang
Grad Year: 2017
Cold work and aging influence the superelastic and shape memory effect in advanced metallic alloys through their effect on retarding plasticity and creating crystallographic texture. Therefore, it is essential to determine the role that aging time and temperature play in the process of obtaining strengthening and recrystallized textures. In our research, Fe-Ni-Co-Al-X(X=Ta, Cr) alloys made by conventional methods, including arc melting, induction melting, hot rolling, solutionizing, and cold rolling are solutionized and aged at different times and temperatures to explore the grain growth, precipitation behavior and recrystallization textures that evolve. The research incorporates many of the most advanced materials characterization tools and techniques, including scanning electron microscopy integrated with energy dispersive x-ray spectroscopy and electron backscattered diffraction, as well as energy-filtered TEM, STEM microanalysis, and x-ray diffraction. These tools and techniques are available in the new NanoEngineering Materials Research Center [NE-MRC], and are utilized here to analyze the phase, microstructure, grain size, and grain texture of these samples. After aging, the hardness of samples is measured to determine the optimum time and temperature for aging, and the corresponding microstructural features that correspond to these conditions. If the Fe-Ni-Co-Al-Ta-B alloy, with its reported exceptional superelasticity (over 13% recoverable strain and a tensile strength over 1 GPa, Science 2010) can be processed through simpler, less costly routes, then it could be used for large scale structural damping. At the same time, if another Fe-Ni-Co-Al-Cr-B alloy with excellent oxidation resistance can also show great superelasticity, it will be widely applied in structural damping field.
Industry Application Area(s)
Civil/Structural Engineering | Materials