-JSWC rR 82-298

THE DETONATION VELOCITY-LOADING DENSITYRELATION FOR SELECTED EXPLOSIVES ANDMIXTURES OF EXPLOSIVES

BY DONNA PRICE

RESEARCH AND TECHNOLOGY DEPARTMENT

26 AUGU3T 1982

Approved for public release, distribution unlimited. D T ICELECTE

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NAVAL SURFACE WEAPONS CENTERm. I, Dahlgren, Virginia 22448 * Silver Spring, Maryland 20910

i2 11 29 018h "',kI

UNCLASSIFIEDIC6ASIFICAION OR --S PA"I_ (Whin Date EntIeId)_

REPORT DOCUMENTATION PAGE RBAO INSTRUCTFORS12. GOVT ACCESSION NO. S .EIPtIS4'i

NSWC TR A2-2g9A5 YgOPqPN CRO ~Ef4. TITL ford Subtti S.

THE DETONATION VELOCITY - LOADING DENSITYRELATION FOR SELECTED EXPLOSIVES AND MIXTURESOF EXPLOSIVES Ptr,MINO Ong. REPORT NU891

7. AUT___________ I. CON" CI OR GIIIAN MUM99(-

Dr. Donna Price

., IEIrOAMING ORGANiZATION NAMEf AND A1QRESS Ia RAM PLE, M9NT,+ PROJ T, TASKNaval Surface Weapons Cent CAA & WORK UNIT NUMI61RIWhite Oak ter .(Code R13) ,61152N, ZROO00101, 2ROIAA,Silver Spring, MD 20910 2R13GA&B

I". CONTROLLING OFFICE NAME AND ADDRESS I. NAiPORT 'ATS26 Auqust 198213. NUMIER 0i PAGES

31,14. 4ONITORING AGENCY NAME & A0OR$SS(II different from Cntrolling OQffice) IS. SECURITY CLASS. (of tell@ report)

UNCLASSIFIEDT13L fL. AUSS1 Il CATION/ DOWNGRACINGO

14. OISTRIOUTION STATEMENT (of this Report)

Approved for public release, distribution unlimited.

I7. DISTRIUTION STATEMENT (of ihe abstract entered In Block 30, it different from Pepoct)

I$- SUPPLEMENTARY NOTES

IS. KEY WORDS (Continue on re e side It necessay and Identify 0X block number)Cetonation Velocity - Lo-ading Density CurvesTNT,, PETN, BTNEU, DINA, RDX (HMX), tetryl, TNETB, mixtures of HE.

0. AASTAACT (Continue on reverse side If necessary ai. Id.etify by blok numbe.Recent detonat'on velocity (D) - loading density (p ) data for pure

explosives have been reviewed and preferred linear D-o 2urves selected.SThese were then used to predict 0 of mixtures at densiies of 1.0 and 1.6 g/cm3The additivity law used was quite successful in both ranges with the exceptionof high porosity PETN mixtures. The Urizar method of prediction was satisfactotyin the low porosity range, but unacceptable in the high porosity range for bothpure and mixed high explosivs (HE). The Kamlet method was satisfactory for13 Qf 15 HF At n $. - glg -ae fnv- I( n f ir.A 0 a I r 4e-g

DD I JOAN' 1473 901ON O 1 NOV 8 IS O La$TI-S-SECURITY CLASSIFICATION OF THIS PAG- (Ron Datae gnterst

NSWC TR 82-298

!,

FOREWORD

This report was prepared under Task ZROOOO101, IR-59 and OMN funds.It is concerned with the relationship between infinite diameter detonationvelocity and loading density of high explosives and mixtures of highexplosives. Methods for predicting the velocity of the latter are alsoconsidered. The results should be of interest to the areas of detonationchemistry andphysics; they are also relevant to the fields of safety andsensitivity.

Approved by:

JAMES F. PROCTOR, HeadEnergetic Materials Division

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NSWC TR 82-298,1

CONTENTS

Page

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1

SINGLE EXPLOSIVES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

TNT. . . . . . . . . . . . . . . . . . . . .. . . . .. .. . . .. . .. 4PETN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

OTHER PURE HE. . . . . . . . . . . . . . . . . . . . . . . . ......... 7

MIXTURES OF HE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. 23

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

ILLUSTRATIONS

Figure

1 DETONATION BEHAVIOR OF HOT-PRESSED TNT. . . . . . . . . . . . .

2 Dt(p) CURVES AND DATA FOR TNT. . . . . . .. . . . . .... . . 53 Dt(pO) CURVES AND DATA FOR PETN...... . . . . .. . . . . . 84 RECENT D(p0) DATA REPORTED FOR DINA. . . . . . . . . . . . . 125 DD(p0) CURVES AND DATA FOR TETRYL. . . .... ............. .. 15

II* - . - - - - . . i

- p ,

NS',JC TR 82-298

TABLES

Table.._,e

1 EXPERIMENTAL VALUES FOR Di(po) OF PETN IN RANGE P0 > 0.95 g/cm3 . . , 92 Di(po) DATA RECENTLY REPORTED FOR DINA. . ... .... .9 9 9.. 113 ADDITIONAL Di(oo) DATA FOR TETRYL. . ............ .... 144 DETONATION VELOCITY OF HE MIXTURES ESTIMATED BY ADDITIVITY,EQUATION 17 .. . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 DETONATION VELOCITY OF PURE AND MIXED HE PREDICTED BY METHOD

OF URIZAR, EQUATION 21. ............... . .... . 196 DETONATION VELOCITY OF PURE AND MIXED HE PREDICTED BY METHOD

OF KAMLET, EQUATION 22. . . . . . . . . . . . . . . . . . . . . . .21

ii1/ivI,ili/ly

NSWC TR 82-298

THE DEIONATION VELOCITY-LOADING DENSITY RELATION

FOR SELECTED EXPLOSIVES AND MIXTURES OF EXPLOSIVES

INTRODUCTION

For many years, it has been accepted that detonation velocity (D) is alinear function of the loading density (po) in the range Po a 1. Indeed, in1945, Hurwitzl published linear relatiuns derived from the extensive ERL datafor numerous explosives. His straight lines were drawn through data of chargesprepared from the finest particle size HE and with the largest diameter atpo k 0.8 g/cm3 . Hurwitz's values of slopes and intercepts hape withstood thetest of time very well; they are quoted in at least two texts' 3 and in ianyreports. However in 1961, it was reported that the D vs Po curve of TNTTshowed a sharp change in slope at Po a 1.5324 g/cm . About nine years later,a st tlar change in slope was reported in the curve for PETN5 at pO a 1.65g/cm.

There is a possible explanation for this deviant behavior, and oneobjective of this work is to point it out. A second is to find an acceptableway to predict the detonation velocity of a porous mixture from a knowledgeof 0(po) of thE components. Finally, the predictions will be compared withexperimental values and with approximations obtained by several methods.

In efforts to obtain high density pressed charges, some investigatorshave used heated molds or solvents or both in the pressing procedure. Ingeneral, there is no record of how this would make the charge behavior differfrom that of the more widely used cold-pressed charges. In particular, itm7y increase the critical diameter dc and hence the diameter effect on D ofany size charge. These effects would be expected for HE such as TNT and PETN

1Hurwitz, M. D., "The Rate of Detonation of Various Explosive Compoundsand Mixtures," OSRD 5611 (1945).

2 Cook, M. A., The Science of High Explosives (New York: Reinhold, 1958).

3Johansson, C. H., and Persson, P. A., Detonics of High Explosives(New York: Academic Press, 1970).4 Urlzar, M. J., James, Jr., E., and Smith, L. C., "Detonation Velocity of

Pressed TNT," Phys. Fluids, Vol. 4, No. 2, 1961, pp.262-274.5Hornig, H. C., Lee, E. L., Finger, M., and Kurrle, J. E., "Equation ofState of Detonation Products," Proc. 5th Symposium (Int.) on Detonation, ONRACR-184 (Washington, D. C.: U.S. Gov. Print. Office, 1972), pp. 503-512.

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NSWC TR 82-298

which flow easily und.r pressure. Rempel 6 has demonstrated the effect forTNT pressed at 72-760C in the presence of a litti.b acetone. Figure 1illustrates it for 8-13 mm dia charges. Since Fi9 . 1 shows the trend dcincreasjng with increasing po, the opposite of that found for cold pressedcharges' it is reasonable to suppose that the hot-pressing (aided by solvent)has not only increased po but also considerably changed the physical natureof the charge. This is particularly likely in view of the low melting pointof TNT (80.50C). In other words the very low porosity, hot-pressed chargesapproach a cast TNT rather than a cold pressed one in their structure. Whileit has not been established that cast and pressed T9T differ in D, it hasbeen reported that at -30 -m dia and po a 1.62 g/cm' the casl TNT has adetonation velocity about 50 m/s lower than the cold pressed,'9.

6 Rempel, fG. G., "Density Dependence of the Critical Diameter and DetonationVelocity of Explosive Charges," PMTF Vol, 10, No. 2, 1969, pm 83-86,through a translation journal.

7 Price, 0., "Critical Parameters for Detonation Propdgation and Initiationof Solid Explosives," NSWC TR 80-339, Sep 1981.

8 Stesik, L. N., and Akimova, L. N., "An Indirect Method of Estimating theReaction Zone Width of a Detonation Wave," Russian J. Phys. Chem., Vol. 33,No. 8, 1959, pp. 148-151.

9 Gibbs, T. R., and Poplato, A., eds., LASL Explosive Property Data(Berkeley: U. Cal. Press, 1980).

3

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NSWC TR 82-298

SINGLE EXPLOSIVES

TNT

Ref. 4 reports what are probably the most precise detonation velocitiesmeasured for INT. However, all charges of o - 1.44 g/cm, were made byhot-pressing (%70 0C). The equation derived fos infinite diameter or ideal

* detonation velocity in tha range po k 0.9 g/cm was

1.8727 + 3.1872 Po 0.9 s Po s 1.5342

6.7625 + 3.1872 (p0 - 1.5342) (1)oi(mm/us) 2

- 25.102 (p - 1.5342)2

(+ 115056 (po - 1..5342)3 1,5342 s Po s 1.636 g/cm3

Recent handbooks 9 ' 10 quote Eq. 1 without the cubic term or any comment on its

absence.

Fig. 2 compares Eq. 1 with that derived by Hurwitz:Dt - 1.785 + 3.225 po (2)

Each curve has been terminated at the highest experimental density reported.The two sets of results are within experimental error except at the higherdensities where hot-pressed charges were used. There Eq. 1 Indicates asharp decrease in the slope; that could result from an increased criticaldiameter such as showii in Rempsei's data. An increased d would increasethe diameter effect on the measured detonation velocity a% any given diameterand hence might result in Dmeasured