1. Mechanical Properties of Hierarchical, Refractory-Based Nanocomposites
Ian McCue1, S. Ryan1, K. Hemker2, X. Xu3, N. Li4 M. Chen3, J. Erlebacher1
Materials Research Society Fall Conference, Boston MA
1 Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218
2 Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218
3 WPI Advanced Institute for Materials Research, Tohoku University, Sendai
4 Materials Physics and Applications Division, MPA-CINT, Los Alamos National Laboratory, Los Alamos, NM 87545
This work is supported by NSF DMR , DMR
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Johns Hopkins University

2. Titanium-Tantalum Precursor Alloys
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Ian Daniel McCue

3. Liquid Metal Dealloying: Titanium Alloys (Ta, W, Nb, Mo)
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Ian Daniel McCue

4. Liquid Metal Dealloying Mechanism (LMD)
Ti-Ta
Ti-Cu
 J. Erlebacher, I. McCue U.S. Patent Application Serial No. 13/975,659 filed on August 26, 2013
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Ian Daniel McCue

5. 2/1/2019
Ian Daniel McCue

6. Ti-Ta(s)+Cu(l) System
Liquid Metal Dealloying
Ti65Ta35 alloy was immersed in molten Cu at 1084 oC
Cu dissolved into this piece over 10 minutes
Result is a composite structure of Cu-Ta with features on the order of 5 μm
Residual Ti conc. ~20 at. %
Elemental mapping shows bright features are Ta and dark features are Cu
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Ian Daniel McCue

7. Controlling Ligament Size
100 nm Ta
30 nm Ta nm
W-Cu
HRTEM Interface
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8. Metal-Metal Composite
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9. Mechanical Testing of Tantalum-Copper Composites
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10. Mechanical Testing of Tungsten-Copper Composites
1.1 μm, 650 nm
nm,
1.5 μm
Pure W
Cu50Ti50-Cu75Ti25
Cu90Ti10
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11. Single Crystal Micropillar Experiments
Uchic MD. et al Science 2004:305;986.
M.D. Uchic, et al. Science 305, 986 (2004)
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12. Deformed Composite
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13. Composite Grain Boundary Engineering
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14. Summary
Original process was created to dealloy and fabricate new porous materials:
Tailorable feature sizes from 30 nm to 10 μm
Novel composites were made:
Fully dense
Interpenetrating bicontinuous networks
Phase separated material with coherent interfaces
Mechanical properties were characterized:
Strengthening effect mirrors effects seen in micropillars
Large, 1 cm3, samples can be fabricated and tested
Relevant structural materials (Radiation Tolerant?)
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Ian Daniel McCue

15. Acknowledgements Jonah Erlebacher (advisor) Erlebacher Research Group
Ellen Benn
Bernard Gaskey
Kevin Hemker (microtensile and compression)
Steve Ryan
Mingwei Chen and Nan Li(TEM)
Xiandong Xu
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16. Questions?
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