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1 AD/A VISCOSITY OF METALS IN EXPLOSION WELDING I. D. Zakharenko, et a' Foreign Technology Division Wright-Patterson Air Force Base, Ohio 19 November 1974 DISTRIBUTED BY: National Technical Information Service U. S. DEPARTMENT OF COMMERCE

2 FTD-HT FOREIGN TECHNOLOGY DIVISION VISCOSITY OF METALS IN EXPLOSION WELDING by I. D. Zakharenko and V. I. Mali DDC JAN 15 14E, C Approved for public release; distribution unlimited. Reproduxced bf NATIONAL TECHNICAL INFORMATION SERVICE N W U S i~j,, If rn Sprmng1iold VA215

3 I NIT DSIW ATA. - & FUNCLASS D "AsonuNap ofufi~ 1not.. 11u b e GROW" ? * M Vg S'ff ,110 REAVI OS.SSOtSS *glvy tgg OWJ aseout 655., V 5ohWCAlow a Foreign Technology Division U. S. Air Force Coinand Systems Force PAir VISCOS,ITY OF M4ETALS IN EXPLOSION WELDING a mgg"y TSII61 * 6SiCRIPYIVIR wevis, (YT'W *##GPM ame kebel,. dwa Translation e ~~i a U?"41S "Sale. W4114 boeisa. lost ue I. D. Zakharenka and V. I. Mali * Rep eadte I&?TAL 14e. ow PAsgi 7. "e or a V11 so. C0122a-4m 6 moa r7esi 6. PSOJISCTINwe FTD-HT * I issooy "0490 (AIW *Off atwe e a be eslpiad Approved for public release; distribution unlimited. AMITRYACT 20, 13 g~jp~i.u~w~is ue?5s a u 0owuom4ws ILIAV ACTIVITyl Foreign Technology Division Wright-Patterson AFB,Ohio id Ih'dSC 1473 UNCLASSIFIED

4 FJD-lHT EDITED TRANSLATION FTD-HT November 1974 CSP VISCOSITY OF METALS IN EXPLOSION WELDING By: I. D. Zakharenko and V. I. Mali English pages: 6 Source: Goreniye I Vzryv Izd-vo Nauka, Moscow, 1972, pp Country of Origin: USSR Translated by: Marilyn O1lechea Requester: FTD/PDTN Approved for public release; distribution unlimited. THIS TRANSLATION IS A RENDITION OP THE ORIGI. NAL FOREIGN TEXT WITHOUT ANY ANALYTICAL OR EDITORIAL COMM9NT. STATEMENTS OR THEORIES PREPARED BY, ADVOCATED OR IMPLIED ARE THOSE OF THE SOURCE AND DO NOT NECESSARILY REFLECT THE POSITION TRANSLATION DIVISION OR OPINION OF THE FOREIGN TECHNOLOGY DI* FOREIGN TECHNOLOGY DIVISION VISION. WP.AS, OHIO. FTDIHT-, Date 9 74

5 All figures, graphs, tables, equations, etc. merged into this translation were extracted from the best quality copy available. I U. *S. BOARD ON GEOGRAPHIC NAMES TRANSLITERATION SYSTEM Block Italic Transliteration Block Italic Transliteration a Aa A, a Pp P R, r BE6 516 B,b C c Cc S" 3ma 0 V v Tt T T,t rr rs G"g Yy Y U,u )I A N Ds d 0. t F f F e E Ye, ye; E, e* XX Xx Khkh * a Zh, zh U a 14 To, ts Sm a 3I. YoX4 Ch, ch HN MU I, i Ww W UMW Sh, sh Pa A n Y, y W X l Iq Shch, shch KM M K,kI & IS o ni J7 L,l hi M ki Y) Yy M- M, m h H i M: N, n a J9. E, e 0o 0.0 O, o t.40 Yu, yu 11 n 17 i P, p RX R Ya, ya ye initially, after vowels, and after -, b; e elsewhere. When written as 9 in Russian, transliterate 's yl or 4. The use of diacritical marks is preferred, but such marks may be omitted when expediency dictates.

6 F01 O.3 ARE THE CGUtIUWING RUSSIAN AND UGLM NSIGNATINS CF THE TRIOM'MRIC IMOMU Russian sin can tg ct bglish fin coo tan cot oh oh th cth Bh cch sinh cooh tanh ooth ech coch arc sin arc coo ow 1 OO8 "1 arc tg tan- 1 arc ctg oot "1 are ec 30c1 l arc cooe 080 " 1 arc oh minh "1 arc ch cooh - 1 are tim tanarc oth coth-1 arc sch ch-1 arc och coch-1 rot Ig curl log FTD-HT ii

7 GREEK ALPHABET Alpha A a Nu N v Beta B 6 xi 2 Gamma r y Omicron 0 0 Delta A~ 6 Pi 11 wy Epsilon E c * Rho P p* Zeta Z Sigma Z a Eta H n Tau T T Theta Upsilon T u Iota I I Phi 0 ff Kappa K X~ K Chi X x Lambda A x Psi ''~ Mu M uomega w FTD-HT

8 VISCOSITY OF METALS IN EXPLOSION WELDING I. D. Zakharenko and V. I. Mali Novosibirsk In the glancing collision of metal plates moving at high rates two different phenomena may occur. At large contact angles a cumulative stream '.s formed [1]. At a smaller contact angle the stream disappears, the interface has a wavy shape [2), and welding of the plates occurs. To describe the flow without the cumulative stream we shall, as in [3), make the following assumptions. 1. The metal of the plates prior to contact and in the same region after contact, where shear forces are not present, is considered an ideal fluid. 2. Metals flowing towether after contact, i.e., behind the point of contact, are considered a viscous fluid. 4contact The excess in the horizontal pulse component at the point of in the case of cumulation is compensated by the reverse stream. In the wave regime the excess in the horizontal component is compensated by the "submerged stream." Its velocity is less than FTD-HT

9 of the contact point, and the stream i. dissipated by the effect - viscous forces. By measuring residual shifts in partizles we can determine the viscosity coefficient of a given metal. Figure 1 shows the experimental scheme. The upper plate 3 was acce.erated by explosion products from the detonation of explosive 5 and oo]lided with plate 1. The impact regime was selected such thait wei.ing of the plates occurred. I5 _.5_.-.. 6_"_ Figure 1. Scheme of experiments: 1-4/ jlower plates, 2 - pressed plate, 3 - upper 2- plate, 4 - pressed wire, 5 - explosive 7 charge, 6 - detonator, 7 - wooden block. After welding the specimens were cut In the direction of motion of the contact point and macrographs were prepared. In the photographs of the sections the horizontal displacement of fixed lines was measured. The characteristic graph representing the experimental dependence of the shift (z) as a function of distance to the interface in the welded plates (g) is shown as a solid line in Fig. 2. Processing the experimental curves zuz(y) 4 for the lower, thicker plate showed that y>6i dt 7h 7 parabola (61 is the thickness of the upper plate) this curve is well described by the equation of the z-a(y-6 2 )2 () Figure 2. Shift in fixed line in (62 - the thickness of the lower plate), shown lower plate: sol- in Fig. 2 by a dashed curve. id line - experiment; dashed line - parabola Let us examine the impact of two metal 2 zia(y-6 2 ) plates at subsonic velocity in a system of coordinates connected to tt'e contact point (0 in Fig. 3). The parameters of the collidiig FTD-HT

10 plated Site Ou011 tlhat tihe OUlU414 IVrO tit volil X -is absent. If we examine the motion of the plates as the impact of streams of an Figure 3. Movemen, ideal fluid at constant pressure, then the of viscocity stream, velocity along the free surface is constant. However, here the law of conservation of momentum along axis x will not be fulfilled: to the right of point 0 the pulse is greater than to the left. We shall assume that the source of impulse is present at the contact point, and at this forms a unique submerged flow of a viscous fluid moving at a higher rate than the rate of contact (U). As we move to the right away from the contact point the submerged stream expands, covering an ever larger region of the flow (hatched region in Fig. 3). Because of the viscosity at infinity the flow rates with respect to plate thickness are never equalized. In the unhatched region of the flow in Fig. 3, where velocity gradients are still absent and viscous forces are not active, a model of an ideal fluid can be used. The coordinate system shown in Fig. 3 was selected such that there is no vertical velocity component to the left of point 0. From the law of preservation of momentum along axis x for colliding plates we find impulse (I) accumulated at point 0 I-PO,8U(-cosy) + t) 1 (--MoV2), where p is the density of the material. If we know the accumulated impulse, then it is easy to determine the velocity of the plates at infinity (ug), the expression for which In the case of plates with the same density, colliding at small angles, has the form of "-= -3 FTD-HT

11 Let us study the diffusion of the horizontal velocity to the right of the contact point, which occurs as a result of viscosity. We will study the case of impact between metals of the same density and viscosity. We have the generalized Stokes equation for steadystate motion of an incompressible viscous fluid *., where p/p is the kinematic viscosity coefficient. Now let us integrate this equation from xn-- to xam everywhere except the line which passes through the contact point: U1,~ doex or U[,,o- X-.] = U,.d-. Here.u(x,,)d-Uz(), where z(y) is the shift in the point from its original position. Since u. represents an addition to the velocity of the contact point to its left, which is equal to zero, we get Then de S(y) =I+Ay+, 2,0 and constants A and B are determined from the following boundary conditions 0- Og,=O when ya62 Finally, we get the shift in the lower plate,si' (2) If we use the reprepentation of (1) for s(y), which is correct for y>61, then from (2) we get FTD-HT

12 The velocity of the contact point was measured in preliminary experiments by means of streak photography. Angle y was calculated from the formulas given in [2]. The re3ults of processing certain experimental data according to foxi.ula are given in the table. J Ilaterial C. x, U i0-5 - O,2 2 12,5 203' 0,5 0, 6 02 luanum (D16) 0.4 $ 3.! 141 0,74 I7 copper 0W " 2.1 I 2.7 0, 'O 2,5,_2.0 Steel ( ,1 15' 3, "' Niobium 0.2 2,9 2.5 I8' ' 2.2 2,2 I 0, ,1 136lO 2,1 2,2 Titanium k 3,% V 4.3 0, , , ,3 1,2 TV 055 0,52 0, 2.7 I,4 9'0 i 0.53 From the data of the table it follows that the numerical values of the viscosity coefficient for steel coincide with the results of studies by A. A. Il'yushin [3] and S. M. Popov [4]; the viscosity coefficients for aluminum coincide with the results of studies by A. D. Sdkharov, and others [5], V. N. Mineyev, and Ye. V. Savinov [6]. The viscosity values for copper and steel do not agree with the data of [5]. One should, however, be wary of tre results of [5], since in the experiments a constant flow behind the front was not obtained. In the opinion of the authors of [5] sufficiently great values for the length and diameter of the explosive charge FTD-HT

13 and also for the diameter of the profile disk should assure a constant flow behind the shock wave front, although in using recesses with ka 0 =l.74, for example, the aperture angle of the latter was 2Y= In this case the stream which we observed is formed at the vertex of the recess. Thus, in the experiments of [5] after a shock wave of sinusoidal profile emerges into a wedge disturbances from the cumulative streams arrive on its surface. These disturbances, already moving through the compressed metal, have a higher velocity than the front of the first sinusoidal wave, and thus overtake it at a certain distance. In this case there is also a phase shift in the sinusoidal disturbance, which was also observed in [5). BIBLIOGRAPHY NoT*N, I. xnya M. A. J" a a Ig7 p t a r b e a. Kymya'mull XI1, sepu 4(761) N npmusuin a. paonl Ycimm 2. X ' A., 1pn c, B. M. KyAuNoo, *. H. Motuoe6NK. o.. i, U lesxuo, 3. Ig67, k A ro I. o.. AL A. Aepn6ac. H. A. 3exapsnno, B. M. Moan. Om. roe. npwua, 197l, Ml. 4. A. A. Hablom nn. Yl. Jan. MFY, awaum a, 1 i4 No. t a, Ii. s C.. nlonoe. Hmotpnul cdopm., Iam.. 6. A. A. Caoopes, P.. 3aAAatb, B. H. Muaso. A F. OaN. u,. Aom. AH CCCP. I96 111,?. mm n. MN u.. L B. C eono. N. ml mpu M M 0., u p. I6. I, FTD-HT