Reactive Materials
Carl Gotzmer
301-653-1000
[email protected]
FOR OFFICIAL USE ONLY
Steve Kim
301-744-1275
[email protected]
1
What are
Reactive Materials?
¾ An energetic material consisting of two or more
solid-state reactants that together form a thermochemical mixture
¾ Typically metal-metal and/or metal-metal oxide
mixtures with and without binders
¾ Materials with higher predicted energy per unit
volume than conventional energetics
¾ Provide alternate kill mechanisms besides those
obtained for conventional energetics
FOR OFFICIAL USE ONLY
2
Benefits of
Reactive Materials
¾ Self-propagating High-temperature Synthesis (SHS)
Reactions - more energy
– More efficient pathways to energy delivery
– More energy per unit volume than conventional
explosives
– Shock sensitivity can be tailored
¾ Ultra-fine powders - energy management
– Energy release rate can be tailored
– More energy than chemical energy (ESM)
– Reactions with water and external air are possible
FOR OFFICIAL USE ONLY
3
Classes of
Reactive Materials
¾
¾
Self-Propagating High-temperature Synthesis (SHS)
– Thermitic - metal/metal oxide reactions
z
Thermite and MIC reactions
– Intermetallic reactions
z
Aluminides
z
Borides
z
Carbides
– Metal/fluorine systems
Ultra-fine powders
– ALEX (exploded wire)
– MIC ingredients
– Nano-laminates
– Mechanochemical Synthesis (MCS)
– Energy Saturated Media (ESM)
– Hf and Ti powders
FOR OFFICIAL USE ONLY
4
Standard Heats of Oxidation of
Selected Metals and Fuels
Metal/Fuel
Aluminum (Al)
Boron (B)
Beryllium (Be)
Carbon (C)
Iron (Fe)
Hydrogen (H)
Lithium (Li)
Magnesium (Mg)
Silicon (Si)
Titanium (Ti)
Tungsten (W)
Zirconium (Zr)
HTPB (R45-HT)
Density of Fuel
gm/cm3
2.7
2.34
1.85
2.25
7.86
--
0.534
1.74
2.33
4.54
19.35
6.49
0.92
FOR OFFICIAL USE ONLY
Main Oxide and
Standard
State
Al2O3(s)
B2O3(s)
BeO(s)
CO2(g)
Fe2O3(s)
H2O (l)
Li2O(s)
MgO(s)
SiO2(s)
TiO2(s)
WO3(s)
ZrO2(s)
--
Gravimetric Heat of
Oxidation
KJ/gm Fuel
31.06
58.74
66.46
32.78
7.39
141.85
43.16
24.73
32.26
19.73
4.59
12.04
43.28
Volumetric Heat of
Oxidation
KJ/cm3 Fuel
83.86
137.45
122.95
73.76
58.09
--
23.05
43.03
75.17
89.57
88.82
78.14
39.82
5
SHS Efficiency
¾ Beryllium – most energetic metal based on weight
¾ Boron – most energetic metal based on volume
Ti + O2
TiO2
efficient
2B + 3/2 O2
B2 O3
inefficient
Ti + 2B
TiB2
~ 7200 °F
TiB2 + 5/2 O2
TiO2 + B2O3
efficient
FOR OFFICIAL USE ONLY
6
SHS Reactions
SHS System
Aluminides
Borides
Carbides
Reactions
Li + Al
Ni + Al
Zr + 2AL
Ti + 2B
Hf + 2B
Ta + 2B
Ti + C
Hf + C
Ta + C
Energy Output
(cal/g)
1130
329
412
1115
394
308
813
277
200
(cal/cm3)
1672
1700
1759
3992
3550
3175
3056
2820
2386
Adiabatic
Rxn Temp
(o K)
2613
1973
1923
4043
3653
2673
3873
4473
3073
Theoretical Max
Density
(g/cm3)
1.48
5.17
4.27
3.58
9.01
10.31
3.76
10.18
11.93
Values from GSI SBIR
FOR OFFICIAL USE ONLY
7
Comparison of Energy Release from
SHS and Explosive Reactions
Composition
(-∆H) [cal/g]
TNT
1,040
1,530
RDX
1,320
2,420
HMX
1,280
2,510
Ti+2B
1,115
3,992
FOR OFFICIAL USE ONLY
(-∆H) [cal/cm3]
8
Potential Applications
¾ Force Protection
¾ Metal cutting/concrete cutting - NSWCIHD
¾ Reactive breaching
¾ Structural energetic composites - NSWCIHD
¾ Reactive explosively forged
penetrators
¾ Reactive fragments - NSWCDD
¾ Reactive filled darts - NSWCIHD
¾ Underwater energy release - NSWCIHD
FOR OFFICIAL USE ONLY
9
Potential Applications (Cont.)
¾ Thermochemical Warheads - NSWCIHD
– High temperature thermal radiators (HTTRs)
– TBXs
– Metal/Vapor Clouds
¾ Agent defeat (heat and biocides) - NSWCIHD
¾ Primers/Detonators
¾ Explosives and burster charge
¾ Propellant additives - NSWCIHD
¾ Decoys
FOR OFFICIAL USE ONLY
10
Advantages of Intermetalic RMs
¾ Adaptable to a variety of applications
¾ 4.1 flammable solid versus 1.1 detonable explosives
¾ Meets Insensitive Munitions (IM) requirements
¾ Minimal gas evolved during combustion
¾ Warhead fill would survive high impacts from penetration
FOR OFFICIAL USE ONLY
11
Appendix
Example of Energy Saturated Media (ESM) and
Underwater Applications
FOR OFFICIAL USE ONLY
12
Why Mechanochemical
Synthesis
¾ Produces activated ultra-fine metal powders (ESM)
¾ Less expensive than vapor deposition
¾ More total energy
– Physical energy
– No oxide coating
¾ Issues
– Less known
– Configuration management
– Processing into compositions
FOR OFFICIAL USE ONLY
13
Thermogravometric Data on
Aluminum Powders
FOR OFFICIAL USE ONLY
14
Example of Stored Energy in Water
Activated Reactive Powder
100
2
WARP - 1, 36.0 m /g
3
75
2
TS-TR [oC]
∆m/∆t [kg/s]
50
25
0
1
-25
0
-50
100 150 200 250 300 350 400 450 500
FOR OFFICIAL USE ONLY
o
TR [ C]
15
Activated Al/H20
Combustion Experiment
FOR OFFICIAL USE ONLY
16