Multiscale Architectured Materials (MAM II): Tailoring Mechanical Incompatibility for Superior Properties: Poster Session
Sponsored by: TMS Structural Materials Division, TMS: Mechanical Behavior of Materials Committee
Program Organizers: Yuntian Zhu, North Carolina State University; Irene Beyerlein, University of California, Santa Barbara; Yves Brechet, Grenoble Institute of Technology; Huajian Gao, Brown University; Ke Lu, Institute of Metal Research, Chinese Academy of Science; Xiaolei Wu, Institute of Mechanics, Chinese Academy of Science
Tuesday 6:00 PM
February 28, 2017
Room: Hall B1
Location: San Diego Convention Ctr
L-172: Principle of One-step Synthesis for Multilayered Structures Using Tube High-pressure Shearing: Zheng Li1; Pin Fang Zhang1; Hao Yuan1; Kui Lin1; Ying Liu1; De Liang Yin1; Jing Tao Wang1; Terence Langdon2; 1Nanjing University of Science and Technology; 2University of Southampton
During the tube high-pressure shearing (t-HPS) process, the traceline of any original radial line segment, with two endpoints located on the inner and outer surfaces of a tubular sample, becomes distorted and elongated. This is an important and intrinsic property of the tangential shear of t-HPS. The new concept of traceline elongation is introduced in order to develop a mathematical description based on the local shear strain. By analogy to the tracelines of interfaces in layered structures, a one-step process is proposed for synthesizing multilayered laminates using t-HPS. It is shown that this process has high efficiency and a low risk of introducing any contaminants. To experimentally verify the feasibility of this proposal, a bimetallic multilayered structure with a micrometer-layer thickness and metallurgical interface-bonding was successfully synthesized using four bulk samples of pure lead and tin as prototype materials.
L-173: Fabrication of Functionally Graded Materials via Asymmetric Cold Rolling: Tyler Harrington1; Jordan Furlong2; Roxan Afshari2; Chaoyi Zhu2; Kenneth Vecchio2; 1Department of NanoEngineering and Materials Science and Engineering Program, University of California San Diego; 2Department of NanoEngineering, University of California San Diego
Asymmetric cold rolling and recrystallization are used to produce a functionally graded structure in Fe and Ti samples that can be used to quantify the correlation between geometrically necessary dislocations (GND’s) and recrystallized grain size. Samples are rolled to various reductions in thickness to induce non-uniform strain hardening throughout the sample, which is measured using hardness profiling. A computational application of Nye’s dislocation density tensor via an EBSD-based GND calculation is then used to quantify the effect of GND density on recrystallized grain size. By gaining a better understanding of the mechanism behind this relationship, materials can be designed with a more precise combination of mechanical strength and ductility. Furthermore, it is found that EBSD is advantageous over TEM to characterize dislocations because GND densities can be quantified, as well as distinguished from statistically stored dislocations.