DTIC ADA586528: Development and Performance of the W/Sb2O3/KIO4/Lubricant Pyrotechnic Delay in the US Army Hand-Held Signal

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by  Defense Technical Information Center

Full Paper
DOI:10.1002/prep.201200109
Development and Performance of the W/Sb O /KIO /
2 3 4
Lubricant Pyrotechnic Delay in the US Army Hand-Held
Signal
JayC. Poret,[a] AnthonyP. Shaw,*[a] ChristopherM. Csernica,[a] KarlD. Oyler,[b] and DevenP. Estes[c]
Abstract: Gassy pyrotechnic delays composed of tungsten, Theadditionof1–5%ofwaxylubricants(stearicacidorcal-
antimony(III) oxide, potassium periodate, and various lubri- cium stearate) was found to have a profound effect on
cants have been developed for use in the US Army hand- burningrate.TheeffectoftungstencontentandtheSb O /
2 3
held signal. The new compositions were developed to re- KIO ratio on burning rate was also probed. A wide range
4
place the current formulation, which contains potassium of inverse burning rates (2 to 15scm(cid:2)1) were demonstrat-
perchlorate and barium chromate, chemicals that are ed, which encompasses the 7 to 8.5scm(cid:2)1 range required
facing increasing scrutiny due to environmental regulation. by the hand-held signal. The W/KIO reaction produces I ,
4 2
The hand-held signal delay housing was used to demon- which was observed by visible spectroscopy in the vapor
strate the burning rate tunability of the new compositions. aboveasampleofcombustionresidue.
Keywords: Pyrotechnicdelays·Tungsten·Periodate·Hand-heldsignal
1 Introduction
Pyrotechnic delays have long been used in munitions to a structural component of the rocket (Figure1). A black
provide reproducible time intervals between energetic powder input charge, the delay composition, and a black
events. US Army hand-held signals (HHS) are used for bat- powder output charge are loaded into the off-center
tlefield signalling and illumination [1]. They contain
a rocket motor and pyrotechnic payload inside an alumi-
num launch tube. When the primer at the base of the tube
is struck, an initiating charge burns and ignites the rocket
propellant. Hot propellant gases ignite a delay element
that burns as the rocket reaches its apex. This delay ele-
mentthenignitesanexpulsioncharge,whichejectsandig-
nitesthesmokeorilluminationpayload.
The current delay composition used in HHS consists of
32.0% tungsten, 56.3% barium chromate, 11.4% potassium
perchlorate, and 0.3% VAAR. (All composition percentages Figure1. The hand-held signal delay housing. The output side
in this article are weight percentages.) This composition is (4.8mmdiameterhole)isshowninthisphotograph.
a variant of the traditional tungsten delay, MIL-T-23132A,
which contains diatomaceous earth as a diluent and no
polymeric binder. Compositions of this type are highly tun- [a] J.C.Poret,A.P.Shaw,C.M.Csernica
able [2]. Varying the W/BaCrO ratio and the metal particle PyrotechnicsTechnologyandPrototypingDivision
4
size gives inverse burning rates ranging from 0.06 to USArmyRDECOM-ARDEC
15scm(cid:2)1 [3,4]. However, chromates and perchlorates face PicatinnyArsenal,NewJersey07806,USA
*e-mail:[email protected]
increasing environmental scrutiny and regulation [5,6]. The
US Army is therefore searching for viable alternatives to [b] K.D.Oyler
ExplosivesTechnologyandPrototypingDivision
thesechemicalcompounds.
USArmyRDECOM-ARDEC
Under the US Army’s Environmental Quality Technology
PicatinnyArsenal,NewJersey07806,USA
Program, a project was initiated to develop a chromate-
[c] D.P.Estes
free and perchlorate-free delay composition for hand-held
DepartmentofChemistry
signals. The HHS delay housing is a 14.5 gram pancake- ColumbiaUniversityNewYork,
shaped piece of aluminum (2024-T4) that doubles as NewYork10027,USA
PropellantsExplos.Pyrotech.2013,38,35–40 (cid:2)2013Wiley-VCHVerlagGmbH&Co.KGaA,Weinheim 35
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1. REPORT DATE 2. REPORT TYPE 3. DATES COVERED
07 NOV 2012 N/A -
4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER
Development and Performance of the W/Sb2O3/KIO4/Lubricant
5b. GRANT NUMBER
Pyrotechnic Delay in the US Army Hand-Held Signal
5c. PROGRAM ELEMENT NUMBER
6. AUTHOR(S) 5d. PROJECT NUMBER
Jay C. Poret, Anthony P. Shaw, Christopher M. Csernica, Karl D. Oyler,
5e. TASK NUMBER
Deven P. Estes
5f. WORK UNIT NUMBER
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION
Pyrotechnics Technology and Prototyping Division US Army REPORT NUMBER
RDECOM-ARDEC, Picatinny Arsenal, New Jersey 07806, USA
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S)
11. SPONSOR/MONITOR’S REPORT
NUMBER(S)
12. DISTRIBUTION/AVAILABILITY STATEMENT
Approved for public release, distribution unlimited
13. SUPPLEMENTARY NOTES
14. ABSTRACT
Gassy pyrotechnic delays composed of tungsten, antimony(III) oxide, potassium periodate, and various
lubricants have been developed for use in the US Army hand-held signal. The new compositions were
developed to replace the current formulation, which contains potassium perchlorate and barium chromate,
chemicals that are facing increasing scrutiny due to environmental regulation. The hand-held signal delay
housing was used to demonstrate the burning rate tunability of the new compositions. The addition of 15%
of waxy lubricants (stearic acid or calcium stearate) was found to have a profound effect on burning rate.
The effect of tungsten content and the Sb2O3/KIO4 ratio on burning rate was also probed. A wide range of
inverse burning rates (2 to 15 s/cm) were demonstrated, which encompasses the 7 to 8.5 s/cm range
required by the hand-held signal. The W/KIO4 reaction produces I2, which was observed by visible
spectroscopy in the vapor above a sample of combustion residue.
15. SUBJECT TERMS
pyrotechnic delays, tungsten, periodate, hand-held signal
16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 18. NUMBER 19a. NAME OF
ABSTRACT OF PAGES RESPONSIBLE PERSON

a. REPORT b. ABSTRACT c. THIS PAGE UU 6
unclassified unclassified unclassified
Standard Form 298 (Rev. 8-98)
Prescribed by ANSI Std Z39-18
Full Paper
J.C.Poret,A.P.Shaw,C.M.Csernica,K.D.Oyler,D.P.Estes
4.8mm diameter cavity, which is only 10.2mm long. In the system, BaCrO serves as the primary “slow” oxidizer, while
4
rocket, the input charge is lit from a small (1.9mm diame- KClO (the “fast” oxidizer)serves tosustain thereaction and
4
ter) hole on the opposite side of this cavity. Since the black sensitize the composition for ignition [2]. In this work, we
powder input and output charges collectively occupy chose to examine Sb O as a BaCrO replacement. In Si-
2 3 4
3mm of length, there is only about 7mm left for the delay based systems, it is known that Sb O and the related
2 3
composition, which must burn for 5 to 6 seconds. There- Sb O give relatively slow burning rates in comparison to
6 13
fore, an inverse burning rate of 7 to 8.5scm(cid:2)1 is required. Bi O [8–11]. While Sb O is not completely benign from
2 3 2 3
The large thermal mass of the HHS delay housing, com- a health and environmental standpoint [12], it is arguably
bined with the long burning time requirement and short an improvement over chromates, which are confirmed car-
burning path, make it particularly difficult to find suitable cinogens [6]. As a KClO replacement, we have examined
4
replacement compositions. In addition, for this application potassium periodate (KIO ). This oxidizer has been known
4
the replacement composition must be lit reliably by black to researchers in pyrotechnics since the 1960s, if not earlier
powder, which has a relatively low flame temperature [7]. [13]. Periodate salts have recently been proposed as re-
We have recently reported that the ternary Si/Sb O/Bi O placements for KClO in flash/incendiary compositions such
2 3 2 3 4
system may be ignited by black powder and is able to as IM-28 [14]. Unlike ClO (cid:2), the IO (cid:2) ion is not expected to
4 4
function in thick aluminum tubes [8], but burning rates competewithI(cid:2)inthethyroidgland[15].
suitable for the HHS could not be achieved in these tubes
or the HHS delay housing due to thermal quenching of the
slower-burningcompositions. 2 Experimental Section
Despite all the difficulties imposed by the HHS delay
2.1MaterialProperties
housing configuration, one advantage of the system is that
the delay composition need not be gasless. This is due to Tungsten (MIL-T-48140, type 2) was obtained from Atlantic
the design of the rocket, in which 15% of the delay cavity Equipment Engineers. Potassium periodate (A11308),
volume is occupied by the black powder input charge that antimony(III) oxide (senarmontite A11123) [16], calcium
vents gases to the propellant combustion chamber; the stearatemonohydrate(39423),andhexagonalboronnitride
delay composition also vents to this chamber. Rugunanan (11078) were obtained from Alfa Aesar. Graphite (282863)
and Brown studied the gassy Si/KNO system and achieved and polytetrafluoroethylene (430943) were obtained from
3
burning rates as slow as 1.7mms(cid:2)1 (5.9scm(cid:2)1) at low sili- Sigma Aldrich. Stearic acid (19–5010) was obtained from
con percentages in stainless steel channels [9]. We ob- Hummel Croton. A Malvern Morphologi G3S optical micros-
tained an inverse burning rate of 3.5scm(cid:2)1 with a 35% Si copy particle size analyzer was used to determine number-
composition pressed in aluminum tubes, but it was ther- based CE diameter distributions; volume-based distribu-
mallyquenchedbytheHHSdelayhousing. tionswerecalculated(Table1).
Faced with these challenges, we returned to the tradi- Scanning electron microscopy (SEM) was performed with
tional W/BaCrO /KClO composition for inspiration. In this an Evex Mini-SEM SX3000 operating at 25keV and
4 4
Table1. Particlesizedata/mm.
Material(Formula) CEDiam.a) D[n,0.1]c) D[n,0.5]c) D[n,0.9]c)
(D[4,3])b) (D[v,0.1])d) (D[v,0.5])d) (D[v,0.9])d)
Tungsten(W) 4.51 1.73 3.46 8.23
(26.57) (6.46) (18.58) (61.25)
Potassiumperiodate(KIO) 4.23 1.29 2.66 7.38
4
(66.75) (26.08) (64.36) (103.8)
Antimony(III)oxide(senarmontite,SbO) 5.39 1.68 4.17 10.05
2 3
(57.86) (9.15) (35.47) (126.9)
Calciumstearate(C H OCa·HO) 5.83 1.82 4.57 10.81
36 70 4 2
(22.23) (7.84) (19.54) (36.60)
Graphite(C) 5.53 2.03 4.57 10.19
(15.81) (6.22) (11.96) (22.99)
PTFE(CF) 9.92 2.91 8.21 18.61
2 4x
(30.07) (11.87) (27.86) (49.72)
Boronnitride(hexagonal,BN) 6.39 2.18 5.53 11.42
(21.79) (7.16) (14.16) (42.68)
Stearicacid(C H O) 11.50 2.40 5.91 25.51
18 36 2
(90.01) (29.36) (83.92) (154.5)
a) Number-based CE (circle-equivalent) mean diameter. b) Volume mean diameter. c) D[n, x] is the diameter at which (100·x)% of the
numberdistributionisbelow.d)D[v,x]isthediameteratwhich(100·x)%ofthevolumedistributionisbelow.
36 www.pep.wiley-vch.de (cid:2)2013Wiley-VCHVerlagGmbH&Co.KGaA,Weinheim PropellantsExplos.Pyrotech.2013,38,35–40
W/SbO/KIO/LubricantPyrotechnicDelayintheUSArmyHand-HeldSignal
2 3 4
equipped with a secondary electron imaging (SEI) detector. diameter, and length of 4.8mm, 9.5mm, and 15.2mm, re-
The sample was affixed to the aluminum stub sample spectively. For these experiments no black powder was
holder with a carbon adhesive tab. SEM indicated that the used and the columns were ignited with an electrically
tungsten used in this study was agglomerates of 2–8mm heated nichrome wire directly. The residue was captured in
particlesandmuchfinersub-mmparticles. a stainless steel cup. Visible spectroscopy was performed
with a Varian Cary 5000 UV/Vis/NIR spectrometer. The resi-
due was placed in a Beckman gas cell with a 5cm path
2.2PreparationofDelayElements
length. Spectra (400–700nm) of the vapor above the resi-
The compositions are dry mixtures of three or four compo- due were recorded at room temperature and at two higher
nents. They were prepared by a combination of mixing (vi- temperaturesbywarmingthecellwithaheatgun.
brational) and screening (80mesh) steps. A die was ma-
chined to hold the HHS delay housing during the loading
and pressing steps. Black powder (class 7, 40–100mesh)
was used for the input and output charges. Pressing was 3 Results and Discussion
performed at 26.8kpsi (184.6MPa) with a 10s dwell time
3.1TheW/Sb O /KIO SystemandtheEffectofLubricants
on aCarver hydraulic press. Toprepare eachdelay element, 2 3 4
50mg black powder was added and tamped, followed by A 40%W, 30% Sb O, 30% KIO composition gave an in-
2 3 4
the first half of the delay composition, followed by press- verse burning rate of 3.34scm(cid:2)1. However, pressing this
ing. Afterwards, the second half of the delay composition composition was complicated by its abrasiveness that
was added and tamped, followed by 50mg black powder, causedthetoolingtobindonmorethanoneoccasion.The
followed by pressing. The input and output charges (the addition of 2% graphite alleviated this problem and also
black powder) collectively occupied 3mm of length in the slowed the burning rate (4.60scm(cid:2)1). Other lubricants at
cavity. The amount of delay composition was chosen so the 2% level also increased burning times, some dramati-
that the total column length, including the input and cally(Table2).
outputcharges,was9.4to10.2mmlong. All the lubricants improved composition packing compa-
rably, with densities as a percentage of theoretical maxi-
mum (%-TMD) ranging from 88% to 92%. Graphite, PTFE,
2.3 TestandAnalysisProtocols
and hexagonal BN all caused a similar increase in inverse
Each finished delay element was held by a clamp with the burning rate, whereas stearic acid and calcium stearate had
small hole facing up. A small amount (20–30mg) of loose a more pronounced effect. The calcium stearate composi-
black powder was placed on top of the small hole. This tion burned at 7.26scm(cid:2)1, more than twice as long as the
was ignited with an electrically heated nichrome wire. Digi- composition without added lubricant. These long burning
tal video recordings were used to ascertain the time be- times are attributed to the ability of stearic acid and calci-
tween ignition of the input and “first light” of the output. umstearateto formamolten insulating waxlayeraheadof
Inverse burning rates (scm(cid:2)1) were calculated by subtract- the burning front. Stearic acid melts at 698C [17] while cal-
ing theburning time of theblack powder layers (collective- cium stearate monohydrate (the type used in this study) is
ly 0.3s) and dividing the resulting times by the lengths of dehydratedat100–1108C,beginstosoftenat1258C,andis
the consolidated delay compositions. Five delay elements molten by 1608C [18,19]. A similar effect was observed in
were prepared andtested foreachcomposition andthere- B C/KNO /KCl smoke compositions, where small percentag-
4 3
sults were averaged; the standard deviations of these es of added calcium stearate increased burning times four-
measurementsweregenerallysmall. fold[20].PTFEalsomeltsalthoughatahighertemperature,
Ejected combustion residue (smoke) was collected by 3338C[21],and isapotent pyrotechnic oxidizer.Hexagonal
burning delay composition pressed into small aluminum BN melts at ca. 26008C [22] and graphite sublimes above
(2024-T3) tubes. These tubes had an inner diameter, outer 36008C[17].
Table2. Effectoflubricantsa).
Lubricant Consolidateddensity/gcm(cid:2)3 %-TMDb) Inverseburningrate/scm(cid:2)1
Nonec) 5.07(0.04) 79.7(0.7) 3.34(0.04)
Graphite 5.39(0.05) 88.0(0.8) 4.60(0.07)
PTFE 5.46(0.03) 89.1(0.5) 4.70(0.10)
BN(hex) 5.35(0.05) 87.6(0.8) 5.01(0.08)
Stearicacid 5.11(0.04) 89.5(0.7) 6.17(0.16)
Calciumstearate 5.34(0.05) 92.3(0.9) 7.26(0.17)
a)Compositionscontaining 40%W, 30% SbO,30% KIO, and2% additionallubricant consolidated at184.6MPa(standard deviationsin
2 3 4
parentheses).b)Consolidateddensityasapercentageoftheoreticalmaximum.c)Nolubricantwasused.
PropellantsExplos.Pyrotech.2013,38,35–40 (cid:2)2013Wiley-VCHVerlagGmbH&Co.KGaA,Weinheim www.pep.wiley-vch.de 37
Full Paper
J.C.Poret,A.P.Shaw,C.M.Csernica,K.D.Oyler,D.P.Estes
Figure3. Effect of added calcium stearate on calculated %-TMD –
Figure2. Effectofadded calciumstearate oninverse burningrate
W/SbO/KIO ratios of 40/20/40 (open circles); 40/25/35 (squares);
–W/SbO/KIO ratiosof40/20/40(bottomcurve,opencircles);40/ 2 3 4
2 3 4 40/30/30 (closed circles). A consolidation pressure of 184.6MPa
25/35 (middle curve, squares); 40/30/30 (top curve, closed circles).
wasused.
Aconsolidationpressureof184.6MPawasused.
Due to its large influence on burning rate, calcium stea- Figure3 show that increasing calcium stearate content re-
rate was selected for further studies. Compositions were sultsinimprovedconsolidation andcorrespondingly slower
prepared with three different Sb O/KIO ratios (20/40, 25/ burning rates, although the effect is greater than the
2 3 4
35, and 30/30) while tungsten was held constant at 40% changes in %-TMD alone would suggest. One reason for
and the calcium stearate level was varied. As with the pre- this may be the ability of molten calcium stearate to flow
vious experiments, the lubricant was added in addition to within the column, increasing the separation between fuel
the100% balanceof theprimary components. Aplot of in- and oxidizer particles. Calcium stearate is also an insulator,
verse burning rate versus calcium stearate level shows and as its content increases the thermal conductivity of the
three stacked curves, one for each oxidizer ratio (Figure2). column decreases. As described below, thermal conductivi-
Generally, compositions with a lower Sb O /KIO ratio typlaysalargeroleindeterminingburningrate.
2 3 4
burned more rapidly than comparable ones with a higher
ratio, although these differences were small compared to
the large influence of calcium stearate. Compositions with
a 20/40 Sb O /KIO ratio (bottom curve) spanned 1.98–
2 3 4 3.2TheEffectofMetalContentandOxidizerRatio
10.78scm(cid:2)1, while those with a 25/35 ratio (middle curve)
spanned 2.49–14.75scm(cid:2)1. The 30/30 Sb O /KIO ratio (top In tungsten-based delay compositions, burning rate is
2 3 4
curve) gave compositions that functioned with up to 3% known to be highly dependent on thermal conductivity,
added calcium stearate, spanning 3.34–10.65scm(cid:2)1; those and therefore on tungsten content [2,24]. In the traditional
with more lubricant only propagated partially and were W/BaCrO /KClO /diatomaceous earth (MIL-T-23132A)
4 4
thermally quenched. Extrapolation of this curve suggests system, exothermicity peaks at 30% tungsten, while burn-
that had these compositions not quenched, the resulting ing rate continues to rise as the tungsten content is in-
burn times would have been extremely long. Greater calci- creased to 60% and beyond [4]. A similar trend was ob-
um stearate content also caused the compositions to con- served in this study (Figure4). When the Sb O/KIO ratio
2 3 4
solidatemoreeffectively(Figure3). was held constant at 1/1 and tungsten content was varied,
In gassy pyrotechnic systems (such as the one in this compositions containing 2% added calcium stearate gave
study), an increase in loading pressure generally results in inverse burning rates from 8.39scm(cid:2)1 (35%W) to
a decrease in burning rate [23]. This is due to a reduction 3.95scm(cid:2)1 (60%W). Compositions containing 25% or 30%
in the number of void spaces, which allow combustion tungstendidnotsustainpropagation.
gases to migrate ahead of the burning front, preheating As shown in Figure2, the Sb O /KIO ratio affects burn-
2 3 4
un-burnt layers [24]. To test the effect of loading pressure, ingrate.Tostudythiseffectfurther,compositionswerepre-
a 45%W, 25% Sb O, 30% KIO , +2% calcium stearate pared with 40%Wand various amounts of Sb O and KIO .
2 3 4 2 3 4
composition was used to prepare delay elements in the All the compositions contained an additional 2% calcium
standard HHS housings. As loading pressure was increased stearate. As Sb O was increased from 10–30% (at the ex-
2 3
from 100 to 400MPa, the %-TMD increased from 84% to pense of KIO ) burning times nearly doubled (Figure5).
4
97% and the burning rate decreased by 25% from 0.20 to Compositions containing 35% or 40% Sb O were thermal-
2 3
0.15cms(cid:2)1. At a constant loading pressure, Figure2 and lyquenched.
38 www.pep.wiley-vch.de (cid:2)2013Wiley-VCHVerlagGmbH&Co.KGaA,Weinheim PropellantsExplos.Pyrotech.2013,38,35–40
W/SbO/KIO/LubricantPyrotechnicDelayintheUSArmyHand-HeldSignal
2 3 4
Figure6. Visible spectra of I vapor above ejected residue after
Figure4. Effect of tungsten content on inverse burning rate. The 2
burning a 40%W, 25% SbO, 35% KIO, +3% calcium stearate
SbO/KIO ratio was fixed at 1/1 as W varied from 25–60%. All 2 3 4
2 3 4 composition. Room temperature (bottom line) and two higher
containedanadditional2%calciumstearate.Aconsolidationpres-
temperatures(middleandtoplines).
sureof184.6MPawasused.Theerrorbarsshowtwostandardde-
viations.
tively. The gassy nature of the composition likely contrib-
utes to this insensitivity to housing material and configura-
tion. Vented gases remove heat from the system that
wouldotherwisebetransferred inparttothehousingwalls
[24].
3.4FormationofI
2
These delay compositions emit purple-tinged smoke as
they burn, leaving a hole down the center of the burnt
columnwithresidueremainingalongthewallsofthehous-
ing.A40%W,25%Sb O ,35%KIO ,+3%calciumstearate
2 3 4
composition was loaded in aluminum tubes without black
powder layers and ignited directly with an electrically
heated wire. Purple I crystals were deposited on the walls
Figure5. Effectofoxidizerratiooninverseburningrate.Composi- 2
tionscontained40%W,10–40%SbO,andKIO (balance).Allcon- of a stainless steel cup when ejected residue was captured.
2 3 4
tainedanadditional2%calciumstearate.Aconsolidationpressure These crystals sublimed rapidly from the warm residue
of 184.6MPa was used. The error bars show two standard devia- whenitwasleftinopenair.
tions.
The characteristic visible spectrum of I vapor [25] was
2
observed when fresh residue was placed inside a gas cell
3.3TheEffectofConfiguration (Figure6). Even at roomtemperature, the purple vapor was
visibleabovetheresidueanditscolorintensifiedasthecell
To test the effect of configuration in this study, a 40%W, was heated. I formation is a general feature of the W/KIO
2 4
25% Sb O , 35% KIO , +3% calcium stearate composition pyrotechnic reactionandisnotcontingentonthepresence
2 3 4
was used to prepare delay elements in the standard HHS of Sb O . Binary W/KIO mixtures, as unconsolidated pow-
2 3 4
housings,2024-T3aluminum tubes,and304Lstainlesssteel ders, ignite with a bright flash and produce copious
tubes. The tubes had the same inner diameter as the HHS amounts of purple I vapor and smoke. While itis a solid at
2
housing cavity but were longer,15.2mm,and had an outer room temperature, I is significantly volatile and is released
2
diameter of 9.5mm. The amount of delay composition as a gas upon formation, thus contributing to the gassy
(0.64g) and loading pressure (184.6MPa) remained con- natureofthesedelaycompositions.
stant so that the resulting columns, including the black
powder input and output layers, were all 10.2mm long.
The inverse burning rate of this composition in the HHS
4 Conclusions
housing is 7.70scm(cid:2)1, which corresponds to a burning rate
of 0.13cms(cid:2)1. The burning rates in the aluminum and The W/Sb O/KIO /lubricant system displays a wide range
2 3 4
stainless steel tubes were only 6% and 2% greater, respec- of burning rates depending on tungsten content, oxidizer
PropellantsExplos.Pyrotech.2013,38,35–40 (cid:2)2013Wiley-VCHVerlagGmbH&Co.KGaA,Weinheim www.pep.wiley-vch.de 39
Full Paper
J.C.Poret,A.P.Shaw,C.M.Csernica,K.D.Oyler,D.P.Estes
ratio, lubricant identity, and lubricant level. Production of I rotechnics Seminar, Denver, CO, USA, June 10–15, 2012,
2
from the W/KIO reaction makes the system gassy, regard- p.494–500.
4
[9] R.A. Rugunanan, M.E. Brown, Combustion of Binary and Ter-
less of which lubricant is used. Of all the lubricants tested,
nary Silicon/Oxidant Pyrotechnic Systems, Part II: Binary Sys-
calcium stearate retarded burning rates the most, and this
tems with SbO and KNO as Oxidants, Combust. Sci. Technol.
lubricant was used to demonstrate inverse burning rates 2 3 3
1994,95,85–99.
out to 15scm(cid:2)1. Importantly these slow rates were ach- [10] L. Kalombo, O. DelFabbro, C. Conradie, W.W. Focke, SbO
6 13
ievedinthehand-heldsignaldelayhousing,whichisamas- and BiO as Oxidants for Si in Pyrotechnic Time Delay Com-
2 3
sive heat sink that readily quenches other slow-burning positions,PropellantsExplos.Pyrotech.2007,32,454–460.
delay compositions. The development and application of [11] A.J. Brammer, E.L. Charsley, T.T. Griffiths, J.J. Rooney, S.B.
Warrington,AStudyofthePyrotechnicPerformanceoftheSil-
highly tunable pyrotechnic delay systems such as this one
icon-Bismuth Oxide System, 22nd International Pyrotechnics
isanongoingareaofresearchinourlaboratories.
Seminar,FortCollins,CO,USA,July15–19,1996,p.447–460.
[12] Chemistry of Arsenic, Antimony, and Bismuth (Ed.: N.C.
Norman),ThomsonScience,London,1998.
Symbols and Abbreviations [13] Theflashpowder“PyrotechnicsLaboratoryFP-684”containing
38% atomized Al and 62% KIO is mentioned: J.A. Carrazza,
4
S.M. Kaye, Compilation of Sensitivity Characteristics of Pyro-
HHS Hand-heldsignal
technicCompositions,February1968,FeltmanResearchLabo-
SEM Scanningelectronmicroscopy
ratories, Picatinny Arsenal, NJ, USA, DTIC Accession Number
SEI Secondaryelectronimaging
AD0827766.
VAAR Vinylalcohol/acetateresin [14] J.D. Moretti, J.J. Sabatini, G. Chen, Periodate Salts as Pyro-
PTFE Polytetrafluoroethylene technic Oxidizers: Development of Barium- and Perchlorate-
keV Kiloelectronvolt Free Incendiary Formulations, Angew. Chem. Int. Ed. 2012, 51,
6981–6983.
mm Micrometer
[15] TheionicradiiofI(cid:2),ClO(cid:2),andIO(cid:2)are220pm,240pm,and
MPa Megapascal 4 4
249pm,respectively:Y.Marcus,IonProperties,CRCPress,Boca
kpsi Kilopoundpersquareinch
Raton,FL,USA,1997.
%-TMD Densityaspercentoftheoreticalmaximum [16] R.G. Orman, D. Holland, Thermal Phase Transitions in
Antimony(III) Oxides, J. Solid State Chem. 2007, 180, 2587–
2596.
Acknowledgments [17] CRC Handbook of Chemistry and Physics (Ed.: D.R. Lide), 85th
ed.,CRCPress,BocaRaton,FL,USA,2004.
[18] M.J. Vold, G.S. Hattiangdi, R.D. Vold, Crystal Forms of Anhy-
The authors thank the US Army for funding this project through
drousCalciumStearateDerivableFromCalciumStearateMon-
theEnvironmentalQualityTechnology(EQT)Program.
ohydrate,J.ColloidSci.1949,4,93–101.
[19] E.S. Lower, Calcium Stearate: Part 1, Pigm. Resin Technol.
1990,19,4–6.
References [20] A.P. Shaw, J.C. Poret, R.A. Gilbert, J.D. Moretti, J.J. Sabatini,
K.D. Oyler, G. Chen, Pyrotechnic Smoke Compositions Con-
[1] J.D.Moretti,J.J.Sabatini,A.P.Shaw,G.Chen,Environmentally tainingBoronCarbide,38thInternationalPyrotechnicsSeminar,
Sustainable Yellow Smoke Formulations for Use in the M194 Denver,CO,USA,June10–15,2012,p.569–582.
Hand Held Signal, 38th International Pyrotechnics Seminar, [21] Y.P. Khanna, The Melting Temperature of Polytetrafluoroethy-
Denver,CO,USA,June10–15,2012,p.445–451. lene,J.Mater.Sci.Lett.1988,7,817–818.
[2] E. Shachar, A. Gany, Investigation of Slow-Propagation Tung- [22] A. Lipp, K.A. Schwetz, K. Hunold, Hexagonal Boron Nitride:
sten Delay Mixtures, Propellants Explos. Pyrotech. 1997, 22, Fabrication, Properties, and Applications, J. Eur. Ceram. Soc.
207–211. 1989,5,3–9.
[3] Tungsten Delay Composition, Military Specification MIL-T- [23] J.A. Conkling, C.J. Mocella, Chemistry of Pyrotechnics: Basic
23132A,16June1972. Principles and Theory, 2nd ed., CRC Press Taylor & Francis
[4] R. Zimmer-Galler, The Combustion of Tungsten and Manganese Group,BocaRaton,FL,USA,2011.
Delay Systems, 19 June 1970, Applied Science Department, [24] M.A. Wilson, R.J. Hancox, Pyrotechnic Delays and Thermal
Naval Ordnance Station, Indian Head, MD, USA, DTIC Acces- Sources (Ch. 8), in Pyrotechnic Chemistry: Pyrotechnic Reference
sionNumberAD0879499. Series No.4, Journal of Pyrotechnics, Inc., Whitewater, CO,
[5] K. Sellers, W. Alsop, S. Clough, M. Hoyt, B. Pugh, J. Robb, K. USA,2004.
Weeks,Perchlorate:EnvironmentalProblemsAndSolutions,CRC [25] R.B. Snadden, The Iodine Spectrum Revisited, J. Chem. Educ.
PressTaylor&FrancisGroup,BocaRaton,FL,USA,2007. 1987,64,919–921.
[6] Chromium(VI) Handbook (Eds.: J. Guertin, J.A. Jacobs, C.P.
Avakian),CRCPress,BocaRaton,FL,USA,2004.
[7] M.E. Brown, R.A. Rugunanan, ATemperature-Profile Study of
the Combustion of Black Powder and its Constituent Binary
Mixtures,PropellantsExplos.Pyrotech.1989,14,69–75. Received:July18,2012
[8] J.C. Poret, A.P. Shaw, L.J. Groven, G. Chen, K.D. Oyler, Envi- Revised:August17,2012
ronmentally Benign Pyrotechnic Delays, 38th International Py- Publishedonline:November7,2012
40 www.pep.wiley-vch.de (cid:2)2013Wiley-VCHVerlagGmbH&Co.KGaA,Weinheim PropellantsExplos.Pyrotech.2013,38,35–40