0
Explosion Mechanics

Investigation of a Nickel-Aluminum Reactive Shaped Charge Liner

[+] Author and Article Information
I. Lewtas

QinetiQ plc,
Fort Halstead, Sevenoaks,
Kent TN14 7BP, UK

N. Harrison

QinetiQ plc,
Cody Technology Park, Farnborough,
Hampshire GU14 0LX, UK

P. Gould

QinetiQ plc,
Bristol Business Park,
Coldharbour Lane,
Bristol BS16 1FJ, UK

D. Williamson

Cavendish Laboratory,
Cambridge University,
JJ Thompson Avenue,
Cambridge CB3 0HE, UK

Manuscript received June 28, 2012; final manuscript received December 26, 2012; accepted manuscript posted January 9, 2013; published online April 19, 2013. Assoc. Editor: Bo S. G. Janzon.

J. Appl. Mech 80(3), 031701 (Apr 19, 2013) (13 pages) Paper No: JAM-12-1270; doi: 10.1115/1.4023339 History: Received June 28, 2012; Revised December 26, 2012; Accepted January 09, 2013

A nickel/aluminum (NiAl) reactive powder system has been investigated to determine its mechanical properties under quasi-static and high rate compression to understand its deformation behavior. A shock recovery system has been used to define shock reaction thresholds under a triaxial loading system. Two nickel/aluminum (NiAl) shaped charge liners have been fired into loose kiln dried sand to determine whether the jet material reacts during the formation process. A simple press tool was developed to press the liners from a powder mixture of nickel and aluminum powder and a simple conical design was used for the liner. The shaped charge jet particles were recovered successfully in the sand and subjected to a detailed microstructural analysis. This included X-ray diffraction (XRD) and optical and electron microscopy on selected particles. The analysis demonstrated that intermetallic NiAl was detected and all the aluminum was consumed in the particles examined. In addition, different phases of NiAl were detected as well as silicon oxide in the target material. There was also some evidence that the aluminum had melted along with evidence of a dendritic microstructure. This is the clearest evidence that the shaped charge jet material has reacted during the formation process. Simulations have been performed using the GRIM Eulerian hydrocode to compare with flash X-rays of the jet.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Schematic illustrating various processes and their associated effects occurring during shock compression of powders (courtesy of N. Thadhani)

Grahic Jump Location
Fig. 2

Particle size distribution for Al powder (left) and Ni powder (right)

Grahic Jump Location
Fig. 3

SEM images of Al powder (left) and Ni powder (right)

Grahic Jump Location
Fig. 4

SEM picture for 75% TMD NiAl (left) and 90% TMD NiAl (right)

Grahic Jump Location
Fig. 5

Experimental arrangement for the determination of the shock Hugoniot

Grahic Jump Location
Fig. 6

Front (dark) and rear (light) gauge traces for high (left) and low (right) velocity impact for NiAl

Grahic Jump Location
Fig. 7

Measured Hugoniot curves for NiAl at 75% TMD

Grahic Jump Location
Fig. 8

Initial EOS for nickel aluminum pressed powder for a range of TMDs

Grahic Jump Location
Fig. 9

Comparison of compaction between that predicted by foam theory and that measured on powders

Grahic Jump Location
Fig. 10

Variation in bulk and shear modulus with density. Equation is trend line on bulk modulus.

Grahic Jump Location
Fig. 11

Comparison of Porter–Gould EOS with Cambridge experimental data

Grahic Jump Location
Fig. 12

Schematic of shock recovery system

Grahic Jump Location
Fig. 13

Photographs of the shock recovery system showing the general deformation and the recovery of sample material for the 955 m/s impact case

Grahic Jump Location
Fig. 14

Micrograph of the polished cross section showing the approximate extent of regions where XRD was taken

Grahic Jump Location
Fig. 15

XRD scan from recovered sample on axis

Grahic Jump Location
Fig. 16

Phase diagram for nickel aluminum powder systems

Grahic Jump Location
Fig. 17

SEM micrograph indicating potential areas of melt (i.e., smooth regions)

Grahic Jump Location
Fig. 18

SEM micrograph from the central part of the reacted powder showing uniformity of NiAl microstructure

Grahic Jump Location
Fig. 19

Boundary between reacted and unreacted material for 606 ms−1 impact case

Grahic Jump Location
Fig. 20

Percentage of material reacted v impact velocity for 60% TMD NiAl in the shock recovery system

Grahic Jump Location
Fig. 21

Simulation “design curves” of maximum pressure v impact velocity for shock recovery rig

Grahic Jump Location
Fig. 22

Photographs of recovered largely unreacted samples (top and middle) compared to a partially reacted sample (bottom)

Grahic Jump Location
Fig. 23

Schematic of NiAl shaped charge design

Grahic Jump Location
Fig. 24

Schematic of press tool

Grahic Jump Location
Fig. 25

Examples of NiAl shaped charge cone and full charge

Grahic Jump Location
Fig. 26

Morphology of pressed powder in liner at apex and base

Grahic Jump Location
Fig. 27

Flash X-rays at 26 (top left), 36 (top right), and 46 μs (bottom) after detonation

Grahic Jump Location
Fig. 28

Comparison of simulation with experiment for unreacted model (top) and reacted model (bottom)

Grahic Jump Location
Fig. 29

Typical appearance of collected debris

Grahic Jump Location
Fig. 30

Optical microscopy showing dendritic microstructure consistent with AlNi (dark) and Ni5Al3 (light)

Grahic Jump Location
Fig. 31

Backscattered electron micrographs showing a segregated microstructure

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In