Session Q40: Metals: Nanoparticles, Compounds and Thermodynamics
11:15 AM–2:03 PM, Wednesday, March 12, 2008
Morial Convention Center Room: 232
Sponsoring Unit:
DCMP
Chair: William H. Butler, University of Alabama
Abstract ID: BAPS.2008.MAR.Q40.5
Abstract: Q40.00005 : Creation of low-energy twin lamellae for thermal stability in nanostructured materials
12:03 PM–12:15 PM
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Abstract 
Authors:
Christopher Saldana
(Purdue University)
Tejas Murthy
(Purdue University)
Ravi Shankar
(University of Pittsburgh)
Srinivasan Chandrasekar
(Purdue University)
Eric Stach
(Purdue University)
Intrinsic thermal instability of nanostructured metals have limited the applicability of these high-strength material systems. A novel stabilization route was discovered in these fine-grained systems when a high-density twin nano-lamella was introduced amongst nano-grain boundaries through SPD at cryogenic temperatures. The stabilization in such a composite microstructure was traced to the peculiar kinematic behavior of the twin-grain boundary triple junction. Copper was chosen as model material and deformed under cryogenic conditions using machining with varying deformation rates. The microstructure was investigated through HREM as a function of time and temperature. At small deformation rates, the SPD at cryogenic temperatures resulted in the creation of a nanostructured material with an unstable microstructure that coarsened even at room temperatures. At higher deformation rates under the same conditions, distribution of twin lamellae resulted in a thermally stable nanostructured material.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2008.MAR.Q40.5