Bulletin of the American Physical Society
17th Biennial International Conference of the APS Topical Group on Shock Compression of Condensed Matter
Volume 56, Number 6
Sunday–Friday, June 26–July 1 2011; Chicago, Illinois
Session T5: Materials Science II |
Hide Abstracts |
Chair: Darcie Dennis Koller, Los Alamos National Laboratory Room: Renaissance Ballroom D |
Thursday, June 30, 2011 11:00AM - 11:15AM |
T5.00001: Effect of Configuration on the Shock Compression Response of Cold-Rolled Ni-Al Laminates Paul E. Specht, Naresh N. Thadhani, Adam K. Stover, Timothy P. Weihs The effects of configurational changes on the shock compression response of cold-rolled Ni and Al laminates are investigated computationally. The laminate geometry provides a unique system with full density and intimate particle contacts. Orientation of the laminate layers and changes in the bilayer spacing are varied in order to understand the resulting changes in the shock wave response. Real heterogeneous microstructures, obtained from optical micrographs, were incorporated into the Eulerian, finite volume code CTH. The results show a marked dependence of the pressure, temperature, and strain response on the underlying microstructure. In particular, two-dimensional effects of strain are seen to increase the dissipation and dispersion of the shock wave, resulting in high levels of viscosity and attenuation. This effect is heightened by the extensive non-uniformities of the layering caused by cold-rolling. Research funded by ONR/MURI grant No. N00014-07-1-0740. [Preview Abstract] |
Thursday, June 30, 2011 11:15AM - 11:30AM |
T5.00002: Fabrication of Nd-Fe-B/alpha-Fe nanocomposite magnets by shock compaction and heat treatment of amorphous alloys Christopher Wehrenberg, Brian Zande, S.G. Sankar, Naresh Thadhani Bulk nanocomposite magnets based on the Nd-Fe-B system were fabricated using mechanical alloying and shock compaction. A high energy ball mill was used to combine Magnaquench MQA-T type Nd-Fe-B powder with varying amounts of pure Fe powder. The resulting mechanically amorphized powders were shock compacted to near full density. Bulk temperature increase during compaction was suppressed by chilling the target fixture with liquid nitrogen prior to compaction. A range of heat treatments were applied to the recovered samples, and the resulting magnetic properties and crystallization behavior were recorded. The presence of additional iron increases magnetization saturation linearly, but decreases coercivity. The coercivity of the shock consolidated compacts showed an increase to a maximum value upon heat treatment of 550 C. [Preview Abstract] |
Thursday, June 30, 2011 11:30AM - 11:45AM |
T5.00003: Mechanical Properties of PZT 52/48 under Shock and Ramp Wave Compression J.L. Wise, S.T. Montgomery, D.P. Jackson, G.E. Clark, E.B. Duckett Complementary gas-gun and electromagnetic pulse experiments have yielded data regarding the dynamic mechanical behavior for poled and unpoled specimens of a PZT (52 wt{\%} lead zirconate plus 48 wt{\%} lead titanate) ferroelectric ceramic subjected to shock and intermediate-strain-rate ramp wave ($i.e.$, quasi-isentropic) loading. For each experiment, velocity interferometer (VISAR) diagnostics provided time-resolved measurements of sample response for conditions nominally involving one-dimensional ($i.e.$, uniaxial strain) compression and release. Wave profiles obtained during the shock experiments have been analyzed to assess the Hugoniot Elastic Limit (HEL), Hugoniot equation of state, spall strength, and high-pressure yield strength of PZT. Profiles from the ramp wave experiments have been processed to determine the locus of isentropic stress-strain states generated in PZT for deformation rates substantially lower than those associated with shock loading. [Preview Abstract] |
Thursday, June 30, 2011 11:45AM - 12:00PM |
T5.00004: Electrical Properties of PZT 52/48 under Ramp Wave Compression D.P. Jackson, S.T. Montgomery, J.L. Wise, G.E. Clark, E.B. Duckett Measurements of electrical responses from ferroelectric ceramic disks under shock wave compression where the directions of wave propagation and remanent polarization are aligned have been conducted on a variety of lead zirconate titanate compositions. Analysis of the electrical responses is complicated by the electric conditions in the disk, tilt in the planar shock, and the variety of material compositions examined. A review of previous measurements on PZT 65/35 ceramic, at stress levels not expected to drive the material into the paraelectric phase and where charge is restricted from flowing from the disk, indicates that above a certain stress threshold the available charge release is complete and the inverse permittivity in the shock compressed ceramic increases linearly with compressive stress. An electrical response model, based on the these observations, is used to explain the electric output from experiments on PZT 52/48 disks under ramp wave compression when the disk faces are connected through a small, or very large, resistive load. [Preview Abstract] |
Thursday, June 30, 2011 12:00PM - 12:15PM |
T5.00005: Shock response of boron carbide based composites infiltrated with magnesium alloys Mathan Kafri, Moshe Dariel, Nahum Frage, Eugene Zaretsky The fully dense composites were obtained by vacuum infiltrating the boron carbide compacts (80{\%} green density) with liquid AZ91 magnesium alloy (850 $^{\circ}$C) and with the melt of 50/50 AZ91-silicon mixture (1050 $^{\circ}$C). The densities, the elastic moduli and the Vickers hardness values of the obtained composites were, respectively, 2.44 g/cm$^{3}$ and 2.54 g/cm$^{3}$, 300 and 350 GPa, and 1200 and 1800 HV. The impact response of the composites was studied in a series of VISAR -instrumented planar impact experiments with velocities of W and Cu impactors ranged from 100 to 1000 m/s. It was found that velocity histories recorded for the composites produced by infiltration with Mg-Si alloy contain a distinct elastic precursor front followed by a plastic ramp. On the contrary, the velocity histories of the composites infiltrated with AZ91 do not display any step-like front; the amplitude of the elastic wave grows gradually from zero level and transforms smoothly into the plastic front. The influence of the composites microstructure on the compressive elastic-plastic behavior and on the dynamic tensile (spall) strength is discussed. [Preview Abstract] |
Thursday, June 30, 2011 12:15PM - 12:30PM |
T5.00006: Fabrication of W-Cu composites by hot-shock consolidation Qiang Zhou, Pengwan Chen, Xiang Gao, Hao Yin In this work a novel approach for producing tungsten-copper composites has been investigated. This approach combines high temperature preheating technique and underwater shock consolidation. By combining these two processes W-Cu composites with various mass ratios were produced. The powders were first blended by mechanically alloying by a planetary ball mill. Prior to application of shock wave, the elemental powders were preheated to different temperatures between 400 and 900${^\circ}$ by heat released from a self-propagating high-temperature synthesis reaction. A water column was used to prolong the duration of shock pulse, uniformize the distribution of shock pressure and reduce the peak of shock pressure, which are of benefit to reduce the cracks in sample induced by shock wave. The pressure history of the powder during the shock process was experimentally measured by Manganin gauges and simulated by using LS-DYNA. The powders were compacted to near theoretical densities. The consolidated specimens were then characterized by SEM analysis, X-ray diffraction, strength and micro-hardness testing. The heat diffusivity and thermo-shock resistance of the consolidated W-Cu composites were also tested and compared with similar compositions manufactured by conventional methods. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700