DE1527577C3 - Process for the production of multilayer bodies by explosive plating - Google Patents

Description

35

The invention relates to a method for producing a substantially continuous metallurgical Connection between two metal plates with the help of explosive force by connecting the two plates with a Angle of 1 to 60 ° to each other made, on at least one of the metal plates a layer of one detonating explosive is applied and this is then detonated.

Belgian patent 599 918 is a method for joining metal layers, especially plates, with the help of explosive force through formation a substantially continuous metallurgical bond. The two metal parts will be at the beginning essentially parallel to one another, but arranged at a distance from one another, an explosive layer placed on at least one outer surface of the metal partner and then on one Point or ignited over an edge.

In this way, the detonation progresses gradually over the whole layer, removing the metal parts are continuously brought to impact each other over the distance, whereby the desired can form a substantially uninterrupted metallic bond. As an explosive device a speed of detonation not exceeding 120% of the speed of sound, preferably less than the speed of sound of the metal in the system with the highest speed of sound.

In "Journal of Applied Physics", Vol. 24, March 1953, pp. 349 to 359, a theory about the flow behavior in the collision area with explosive cladding for radiationless cases due to the dynamic Established conditions of a compressible flowable medium. The critical collision angle is used as the Function of the material speeds and the material properties determined from the state equation, over which a beam should form due to the collision. Some experimental attempts between metal plates that were driven together with a high explosive charge yielded sufficient good agreement with the theory developed there. This whole treatise is what it is purely theoretical considerations, which do not indicate the possibility of the connection massive Objects can be removed by explosive force.

There was already the possibility of arranging the metal plates to be connected at an angle examined. The apparent advantages of an angular arrangement over parallel arrangement, such as it is described in Belgian patent 599,918 above is the greater variability of the disintegrant. The angular arrangement allows the application of explosives with higher detonation speed compared to the parallel arrangement. The usual explosives should be usable for angular positions, whereas for parallel ones Arrangement special explosives had to be developed, which a safe detonation with lower ones Ensure speeds as required in the parallel arrangement. Such Investigations with angular adjustment are the "Dissertation of Z a b e 1 k a", Explosive Welding of Metals, University of California, Los Angeles, USA, 1960. Zabelka concludes that Explosion plating only leads to reproducible results if certain conditions are met The speed and angle of the service are adhered to. The lower critical one Impact angle was in good agreement with a theoretical lower critical jet angle, so that Zabelka concluded that the explosive plating was the result of a collision Is jet formation. Neither Zabelka nor anyone else at that time had the necessary for the practice Parameters set up for a perfect connection. However, some have older editors Label paths in the other direction.

The object of the method according to the invention is now to solve the problem of determining Factors and parameters, compliance with which is critical for a secure connection of the two metal parts, if an angular arrangement is assumed.

The method according to the invention is based on the above-mentioned explosive plating process and is now characterized in that an explosive layer is used with such an explosive weight per unit area that upon detonation the collision pressure P exceeds the elastic limit of the metal with the lowest elastic limit in the system and that upon ignition of the explosive at least one of the ratios of the collision speed to the speed of sound in the metal layers is V _c : C <1.2 with the proviso that - if the ratio of each collision speed to the sound speed of the corresponding metal layer is 1 < V _c : C <1.2, so that oblique shock waves occur according to the laws of fluid mechanics, the

cause a flow deflection, which manifests itself in the plates as a bend with the angles ^ ₁ , <p ₂ - the collision angle Ψ between the two metal parts in the collision area exceeds the maximum value Φ of the entire bend (0 _t + Φ ₂ ) as a result of the oblique shock waves.

The invention is explained in more detail with reference to the figures.

F i g. 1 is a cross-section of an arrangement for carrying out the method according to the invention, wherein a layer of detonating explosive is on the outer surface of one of the two metal layers is arranged.

F i g. Figure 2 is a cross section of another arrangement.

F i g. Figure 3 is a cross-section of an arrangement during detonation of the explosive layer at the External surfaces of the two metal layers.

F i g. 4A through 4E are top plan views of assemblies, each with a layer of explosives on one detonated single point (Fig. 4C, 4 D, 4E) or along a line (Fig. 4A, 4 B) of the explosive layer will.

F i g. 5 and 6 are schematic representations of the shape and arrangement of the components in explosive cladding as well as the force directions or vectors when using one (Fig. 5) or two (Fig. 6) Layers of explosives.

F i g. 1 shows the metal layer 1 in connection arrangement with the metal layer 2, which is on a Carrier 3 - e.g. B. made of metal, wood or plaster - rests while the angle <5 is held between the Metallschichteri 1 and 2 by means of a spacer 4. The layer of a detonating explosive 5 is connected to the detonator 6 via power supply lines 7 to one Power source arranged on the outer surface of the metal layer 1.

F i g. 2 shows the metal layers 1 and 2 on the carrier 3. An explosive layer 5 with detonating cord 8 is arranged on each outer surface of the metal layers, and the detonators 8 are connected to the detonator 6 Connected via power lines 7.

The explosive layers can be detonated in any conventional manner, e.g. B. with a primer, a fuse wire, fuse, line wave generator, surface wave generator or a suitable one Combination. The ignition point of one or both layers can be at one point, e.g. B. at one point an edge, a corner or in the middle of the layer, or along a line, such as a layer edge, or take place simultaneously over the entire layer surface. If more than one layer of explosives is used, should both layers be ignited at the same time at corresponding points of the two layers in such a way that that the detonation propagation is essentially the same in both layers.

It seems appropriate to explain the mechanism of bond formation so far that the invention Process becomes easier to understand.

It can be assumed that the formation of a continuous metallurgical bond between the facing surfaces of two metal layers or plates depends on the "beam" - Phenomenon which is shown in FIG. 3 for an arrangement according to FIG. 2 is indicated schematically. Will the Explosive layers 5 are ignited and the gaseous detonation products 9 develop the detonation creates a pressure that drives the two metal plates against each other. When the metal plates meet at a suitable angle and the collision area progresses over the metal plates at a suitable speed, so the pressure occurring during the collision becomes effective somewhat beyond the collision area and throws the surface layers of the opposing metal plates at high speed from the collision area to the front, d. H. creates a ray 10. Removal of the superficial Oxides and other contaminants from the jet allow intimate contact with the one below "Pure" metal of the two opposing plates and thus the formation of one uninterrupted metallurgical connection 11 at the common interface of the two plates. In some cases the jet escapes completely, removing the superficial ones between the two plates Oxides and other impurities from the system to be connected. In other cases it will the blasted material enclosed between the two plates. In this case, the high kinetic leads Energy of the beam to melt the adjacent clean surfaces of the metal plates, and the melt solidifies very quickly, leaving behind a connecting zone, which is due to the presence of a homogeneous Mixture of the metals of the two opposing plates is characterized, the connection zone which contains surface contaminants in a disperse state, making them the compound do not hinder. The connecting zone can consist of a uniform layer of the homogeneous mixture of the metals of the two opposing plates. If the included ray that the As the collision zone advances, vibrates, the connecting zone contains only separate nests of the mixture at more or less regular intervals across the intermediate surface of the plates. In any case it will be a flawless, substantially continuous, metallurgical bond obtained.

The appropriate collision angle and collision speed for the formation of a beam will vary from system to system, but may be determined for a given system and so may the process conditions be chosen that the collision of two given metal plates at the required angle with the necessary speed is guaranteed.

It seems appropriate to define the terms, designations and abbreviations used first, as in Fig. 4 to 6 shown. ■, · '.' '·

1. Metal plate.

2. Metal plate.

Speed of sound in P1 or P 2.
Detonation speed of the explosive.

Collision speed for P1 or P 2. Impact speed of P1 or P2.

Vp ₁ + Vp ₂ (relative disk speed).

Impact angle from Pl to P 2
(Collision angle).
Starting angle between P1 and P 2
(measured in the plane perpendicular to the imaginary cutting line AB).
Angle between the collision plane and the starting plane of Pl or P 2.

Cl,
55 60 Pl
P2
C2
D. Vcu
Vpi, Vc2
Vp ₂ Vp ψ ö

Φι, Φι

X ₁ , X ₂

Vi ⁼ angle between the collision area and the initial plane of Pl or P2 with advancing detonation front. δ + _γι + γ ₂ .
Bend angle from Pl Shock wave effect.

The turning angles Φ _χ , Φ ₂ can be calculated from the behavior of the oblique shock waves

or P2 under

= φ ₁ + φ ₂

Propagation angle of the detonation front between the imaginary line of intersection AB and the direction of the advance of P1 or P2.
P = pressure behind the shock wave front.

P ₀ = normal pressure.

ρ = density in the metal plates behind the shock wave front.

ρ ₀ = density in the metal plates in front of the shock wave front.

U _M = The change in material speed caused by the shock wave.

U ₃ = shock wave velocity perpendicular to the wave front.

It is assumed that the values for the collision speed F _a , F _{C2 of} the plates 1, 2 and the collision angle Ψ change so slowly as the collision progresses that the metal flow in the collision area can be approximately described as a locally steady flow at any moment, see above that the laws of fluid mechanics are applicable.

If F _a <C ₁ and / or F _c2 <C ₂ , a connection is obtained as long as the relative disk speed (V _P ) exceeds the minimum value required to generate sufficient pressure in the collision area to produce an elastic Overcoming elongation or exceeding the elastic limit of at least one of the metal plates and thus achieving the plastic deformation required for beam formation. The minimum value for V _{P of} any particular metal system depends on the properties of the metal plates and increases with increasing strength, hardness and surface roughness. This minimum value of V _P for connecting e.g. B. corrosion-resistant steel with carbon steel is around 90m / sec when the metal surfaces are fairly smooth.

If both F ₀₁ > C ₁ and F _C2 > C ₂ , the collision leads to the formation of oblique shock waves in both plates. If these shock waves are on the collision line, the pressure resulting from the collision cannot be transmitted in front of the shock waves, i.e. cannot come in front of the collision area, and thus no jet can form, which means that the surface contamination remains in the interface and prevents a connection will. The inclined, adjacent, ie non-detaching shock waves lead to a deflection of the flow, which manifests itself in a sharp bend in the metal plates 1, 2 at angles Φ _γ , Φ ₂ . The applied shock waves are reflected from the outer free surfaces of the collided plates as returning waves, which causes either the separation of the plates at high speed or a chipping of one of the plates. Under these conditions (applied shock waves) the angle between the plates in the collision area Ψ is less than or equal to the sum Φ of these bends, ie Ψ ^ Φ = Φ _χ + Φ ₂ .

tan Φ _ι =

TJ ^U

(V ² - TJ ² Y ¹²
\ ^y Cl ^U S)

V ^{2 V} C1

(1)

and (2) analogously for tan Φ ₂ .

The velocities U _s , U _M stand with the pressures P, P ₀ and densities ρ, ρ _{0 in} front of and behind the wavefront in the metal plates via the equations

= Q- (U ₅ - U ") P - P ₀ = Qo-Us-U _M

in relationship.

The normal pressure. P ₀ of about 1 at is negligible compared to the pressure P behind the wavefront, so that it follows:

P = ρ ₀ · U _s ■ U _M.

(5)

A considerable amount of data is available in the literature, generally in the form of Hugoniot curves, which give the relationship between pressure and volume (= l / ρ) behind the wavefront in many metals. By inserting values for pressure and volume (= l / ρ) into the mechanical wave equations, values for U _s , U _{M are obtained} . However, U _s , U _{M can} also be determined experimentally (see Wash, JM, Rice, MH, McQueen, R. C, and Yar ge r, FL, Physical Review 108, 2, 196, 1957). Many values for Φ _1; Φ ₂ at a number of pressures are measured and added to Φ; the values of Φ are finally plotted in a diagram against the pressures P, whereby the maximum value Φ _Η is obtained, which must exceed the value of! P in order for a jet to be formed.

However, if V _P exceeds a minimum value, which is necessary so that the collision angle Ψ is above the critical value _Φ Ιί, the oblique shock waves are detached from the collision area and face the collision line. Under these conditions the pressure is transmitted in front of the collision zone and leads to the formation of a jet, which enables a connection. The value of this critical angle varies from system to system and is dependent on F _a and F _C2 as well as the properties of the metal plates 1 and 2.

If F _a : Cl and F _C2 : C2> 1.2, a very good connection will not be achieved even if a ray occurs. Under these conditions, an extremely high relative disk speed V _{P is} required in order to create the conditions for the formation of a jet, ie so that Ψ> Φ *. The excessively large explosive charge which is required to produce these high plate speeds often leads to a deformation of the arrangement to be connected. In addition, the severely detached shock waves, which are reflected from the outer free surfaces of the panels to be connected as recoil waves, cause temporary connections to break open and contribute to deformation and breakage of the panels.

From the above it is clear that the values which are always prior to the choice of the process conditions must be determined in order to ensure the beam formation and connection, the sound

speed Cl, C 2 in plates 1 and 2, the speeds V _cu V _C2 at which the plates move into the collision area, and the relative plate speed V _P. Each of the disk speeds V _P or V _n and V _P2 can be determined by a variety of known methods, e.g. B. using electrical contact pins (D. Bancroft et al, in "Journal of Applied Physics", 27, 3, 291, 1956) or by an optical method (WA Allen, ibid. 24, 9, 1180, 1953) or with a flash X-ray radiogram (AS Baichan, ibid. 34,2,241,1963).

In addition - if Cl < V _C1 < 1,2-Cl and C 2 <F _c2 < 1.2 · C 2 - the angle Ψ at which the plates 1 and 2 meet and the critical collision angle Φ _Η , which must be exceeded for jet formation can also be determined.

The speed of sound in metals is given in Belgian patent specification 599 918, pp. 22-23.

The methods for determining F _C1 , V _C2 , V _P and Ψ are to be shown using the force vectors in some embodiments of the method according to the invention.

If one considers z. B. an arrangement according to Fig. 1, but the ignition of the entire layer of explosive takes place simultaneously with a surface wave generator, it is shown that the detonation pressure quickly accelerates the metal plate 1 on top of it to a high speed. In general, the maximum speed of a plate is reached at a distance corresponding to the plate thickness; Sufficient speeds for the connection can be obtained at a distance corresponding to a fraction of the panel thickness. Since the explosive layer 5 is uniformly thick and has the same properties over the entire surface, the adjacent plate 1 moves essentially perpendicular to its plane of origin at a speed V _n , ie equal to the relative plate speed V _P , and hits the plate 2 in an angle Ψ which is equal to the starting angle δ between the plates. In this first case, therefore, V _CI and V _C2 can easily be derived from the equations

V _CI , V _C2 result from δ, V _PU, V _P2 and V _P.

Pl

tan

V _cl =

δ and V _C2 = F _P / sin δ

calculate.

If one considers an arrangement according to FIG. 2 and ignites both layers of explosive at the same time with a surface wave generator, the calculations are a little more complicated. The plate 1 moves at a speed V _n and the plate 2 at a speed V _P2 . The relative disk speed Vp is therefore the vector sum

Σ V _n + F _P

F _P2 .

V _P2

] F _P1 -Fp ₂ -cos ₍ V (6)

_{The plates 1, 2} meet one another along a collision plane which includes an angle δ _χ or δ 2 to their starting planes. These angles can be calculated from V _n , Fp ₂ and F _P.

cos O ₁ =

V _P2 + Fp ₁ * cos δ

and (8) analogously for cos (

and (10) analogously for F _C2 .

However, if an explosive layer as shown in FIG. 4C, 4 D and 4E at a single point or as shown in FIG. 4A, 4B ignited along a line and not with a surface wave generator, the detonation proceeds over the entire explosive layer at the detonation speed D in a direction essentially parallel to the initial plane of the adjacent plates. The pressure generated acts progressively on one plate and drives it against the other plate, ie the pressure first acts on the parts of the adjacent plate which are closest to the ignition point or the ignition line. This is in FIG. 3 shown. Under these conditions, in the collision area, the metal plates 1 and / or 2 are bent by an angle γ _χ and / or γ ₂ to their original planes and proceed at a speed F _P1 and / or V _P2 in directions that are at angles ^ ₁ / 2 and / or y ₂ j2 are perpendicular to their original planes. These angles γ _χ , γ ₂ should be taken into account in all calculations for F _C1 and F _C2 if the ignition occurs from a point or a line. The angles can be determined experimentally - like F _P1 , V _P2 - or by calculation using the detonation speed D. Finally, the angles λ are also of importance, which for a given plate arrangement can vary at an initial angle δ , depending on the direction in which the detonation progresses over the explosive layer.

If a layer of explosive is used on each of the plates 1 and 2 (FIG. 2), both should have essentially the same detonation speed and be ignited in the same way, that is, the progression of the detonation is the same, X ₁ = X ₂ = λ; which can be easily determined in a known manner.

The Fi g. 4 C, 4 D and 4 E show the values for;. at different points on the surface of the arrangement to be connected when the explosive layer 5 is detonated at one point (e.g. by detonator 6 with connections 7). As can be seen from the figures, the line AB approaches the cutting line of the plane of the plate. The direction in which the detonation progresses is indicated by arrows; the extrapolated detonation path is shown interrupted. It is possible _{to calculate F C1} (or F _C2 ) from mathematical equations for D, X, O ₁ and y _x (or δ ₂ , γ ₂ ) if the ignition takes place at one point. However, the equations are much simpler with edge ignition as shown in Figures 4A, 4B. The geometric relationships of F _n , F _C2 , D, V _P , δ, Ψ and γ _χ to one another with only one layer of explosives on the plate 1 and ignition as shown in FIG. 4A (A = 90 °) are in FIG. 5 and with two layers of explosives (on plates 1, 2) and simultaneous ignition in FIG. 6 shown.

If the explosive layers are detonated at a point, along a line or across the area, it is necessary to determine _{F n} , V _{C2 for a given system.} If only one layer of explosives on z. B. plate 1 is ignited at a point or along a line, so F _C1 and F _C2 depend on h, γ _χ , Χ and D from; an explosives-

309 528/116

10

layer ignited simultaneously at a point or along a line, then F _C1 depends on O ₁ , Y ₁ , A and D and V _C2 on <5 ₂ , γ ₂ , A and D.

In the case of only one layer of explosives, the angle δ is known and the angle A can easily be determined in a known manner from the progression of the detonation which was ignited at a point or along a line of the layer. The turning angle γ _χ can be determined experimentally, as with the measurement of V _n ; but you can also Y ₁ from the known

io detonation speed D and the experimentally determined plate speed V _n according to the equation

y = 2 D ■ sin (y / 2) (11)

and determine the same for Fp ₂ .

The collision speeds Vq ₁ , V _{C2 of} the plates 1, 2 are obtained by inserting the values for <5, Y ₁ (γ ₂ ) and D in the following equations and solving the equations for Vq ₁ and V _C2 .

sin arctan
cos A

(1 - tani ^ / 2) tan <5 sinA) sinA · cosA

₁ + COSy ₁ tan <5 sinA ■ (1 - tan (y _t / 2) ■ tan <5 sinA)

· COS ² A

Ί ² A J '

V _C2

sin arctan

■ t

sinA-cosA

A-cosA Ι

■ tan <5 · sinA - COS ² A) J

D cosA Leos « ⁵ " (1 + coty _t

These formulas can be simplified for ignition over an edge: A = 90 °, Fi g. 4A.

F _cl _ SHIy ₁ COS (yj / 2) + <5) .... F _C2 _ SHIy ₁

~ D ~ Sm (Y ₁ +0) cosfo / 2) ⁽ ' D sin ( _yi + δ)'

If A = 0 or 180 ° (Fig. 4B), slightly different equations are necessary.

D ~ (sin ² yi + tan ² «5) ^1/2

ci D ~ (tan ² y _x + sin ²

Modifications may also be necessary if there is a layer of explosive on each outer surface of the two Metal plates is applied.

D is known, Y ₁ and y ₂ can be calculated as above, <5 _l5 b ₂ result from:

S ₁ + O ₂ = δ

cos O ₁ (1 + cot Y ₁ ■ tan O ₁ · sin / - cos ² λ) = cos δ ₂ (1 + cot y ₂ · tan <5 ₂ · sin λ - cos ² λ). If one now knows O ₁ , <5 ₂ , y _l5 y ₂ , λ and D, one can determine F _C1 and F _C2 .

^r egg
D.

sm · arctan
cos A

si

(1 - tan (y _t / 2) ■ t an O ₁ ■ sin A) · SHIy ₁ · sin A · cos Λ

siny _t + COSy ₁ ■ tanöi ■ sinA - (1 - tan (y _t / 2) · tan ^ ₁ · sinA) · SUIy ₁

-COs ² A) J

and analogously (21) for

If F _C1 <Fp ₁ and / or F _C2 <F _P2 , only one bond is achieved as long as F _{P is} sufficient to overcome the elastic limit of at least one plate. With point ignition, F _P = V _P1 , with line ignition, V _{P is} a function of F _P1 and F _P2 .

2 Vp

V _P2

arctan (tan <5

■ sin A) I.

In both these cases, F _P1, F _P2 higher than the acoustic velocity of the plates 1, 2. It must therefore determined Φ and Ψ are adjusted so that Ψ> Φ. For area ignition, Ψ = δ. The following applies to point and line ignition

₂
cos Ψ - ^C1

₂
^C2 ~ ^p

2 V

(23)

_C i

V _C2

With an appropriate choice of the starting angle <5 between the metal layers and the explosive charge, the detonation speed D and the type of ignition of the explosive layers, it is possible to meet the two critical requirements for the connection.

It has been found that - if the starting angle between the metal layers is between about 1 and 40 ° - the method according to the invention can be carried out without excessive deformation of the composite body. At δ> 60 °, however, the composite body is often severely deformed as a result of the forces arising from the detonation of the explosive layers. The reason for this, as the distance increases, is likely to be the relatively large air gap to be bridged during the plating, which possibly acts as a cushion or buffer and prevents the layers from being accelerated to the speed required for a bond. The layers can "rattle" or vibrate as they move towards the collision area. The metal layers do not really need to touch, but can be reached through a small distance

the point or line that intersects the Levels closest to each other. It should be as small as possible; in general is a distance greater than about 25.4 mm is neither necessary nor desirable.

The term "explosive charge" refers to the weight distribution per unit area of the explosive layer. You can also use a conventional buffer material between the explosive layer and the adjacent one Arrange metal layer to avoid surface contamination or roughening of the metal layer to prevent.

The amount of explosives required to join two plates of corrosion-resistant steel equal Size needed is approximately the same when the initial angle between the metal layers 5 and 32 ° is. The determination of the respective amount of explosives to be used or the weight per unit area and the Explosive charges are well known. As stated above, the explosive charge must be sufficient in any case to create a collision pressure that is the elastic limit of at least one of the metal layers exceeds.

The explosive used should be a detonating explosive. In general, the minimum is Detonation speed of the explosive at least about 1200 m / sec and the maximum detonation speed no more than about 9000 m / sec. If more than one layer of explosives is used in a process step, the both layers have at least approximately the same detonation speed.

The method according to the invention is based on the connection of a large number of metals such as steel, Copper, aluminum, iron, titanium, niobium, cobalt, nickel, beryllium, magnesium, molybdenum, tungsten, Copper, gold, their alloys and other metals are applicable, some of them being customary It is extremely difficult to combine procedures. As stated above, any metal layer made of a metal, an alloy of two or more metals or a multilayer body consist of two or more individual layers. The only limitation in physical properties of the metal layers is that they must be ductile. The metal layers do not require any Preparation, however, it is desirable to degrease and / or lightly grind them.

The metal layers can have any dimensions and do not have to be flat plates be of uniform thickness. For example, one or both of the layers may be wedge-shaped; H. of changeable Be thick, arcuate, cup-shaped, or bent at any angle. Furthermore you can connect more than two metal layers in a single process step, for example by inserting an intermediate sheet between two outer layers to be connected. One or multiple layers of metal may be part of the surface of a device to be coated should be applied.

When carrying out the method according to the invention, the most varied of arrangements of the metal layers to be connected can be used. The metal layers can be on a line or at one point, e.g. B. touch at a corner on the inner surface of each of the layers, it is also possible to arrange the metal layers at a small distance from one another at a point or along a line which is closest to the intersection of the layer planes. However, since no jet formation takes place without the layers reaching a certain minimum velocity V _P against each other before the collision, with this arrangement a small area - adjacent to the line or the point of contact of the two metal layers - remains unconnected in an otherwise continuously metallurgically connected System.

The starting angle δ need not be constant over the entire area of each layer. So is z. B. if the inner surface of one or both of the metal layers is curved or cup-shaped, the angle δ between the plane of tangency to the inner surface of the layer at a given point and the plane of the inner surface of the layer to which it is to be bonded becomes δ measured in a plane perpendicular to the intersection of these two planes. If more than two metal layers are to be connected in a single process step, the angle δ between each two adjacent layers can be the same as or different from the angle <5 between two other adjacent layers.

The way in which the starting angle δ is maintained before the explosives are ignited is not critical, for example by placing an edge of one layer against the corresponding edge of the second layer in such a way that the metal layers "stand" on a base, as is shown in FIG F i g. 2 is shown. However, it is also possible to use carriers, e.g. B. spacers or stiffeners according to Fig. 1, to use, as long as the carrier does not adversely affect the connection process, that is, that larger areas of the surfaces to be connected are not shielded or the acceleration of the metal layers caused by the ignition of the explosive layers is delayed. If the metal layers to be connected have overlapping parts made of the same or different metal surfaces, e.g. B. when connecting pipes or plates, δ is adhered to by bending one overlapping end away from the other. Rigid supports for the entire assembly to be connected, as shown as 3 in FIG. 1 and 2 are not necessary and the whole arrangement can e.g. B. be immersed in water.

The composition of the explosive layer is not critical. For example, you can do a shift from a cast, granulated, gelatinous, flexible or fibrous disintegrant based on Pentaerythritol tetranitrate, cyclotrimethylene trinitramine, trinitrotoluene or ammonium nitrate or a mixture thereof with each other or with other explosives or non-explosive substances for the invention Use procedure.

It is also possible to have an arrangement of metal layers to be connected on each of the two opposite ones Sides of a single layer of explosives to be arranged, so that you have two composite bodies at the same time can get.

A limitation on the starting angle and on the charge, the detonation speed and the manner in which explosives are detonated is that they must be adapted to the two mentioned critical requirements for the connection are met, namely the ratio of collision speed to the speed of sound, and that

the angle between the metal layers in the collision area exceeds a critical value.

The method according to the invention can be used in a particularly suitable manner for the seam welding of metal surfaces to form long, flat, uninterrupted surfaces or rectangular containers as well as for welding pipes. If, with such measures, the length of the surfaces to be connected is significantly greater than their width, the explosive layers are expediently detonated at such a point on the layer that λ = 0 over a substantial part of the layer, ie that the detonation over the length of the Layer progresses parallel to the junction between the two layers.

The method according to the invention is also particularly suitable for joining thick metal layers, ie 2ϊ 12.7 mm. If a relatively large starting angle δ is used and the process conditions are such that the jet exits completely between the layers, a thin bond zone can be achieved, which essentially represents a direct metal-to-metal bond and not so much a thick layer of solidified melt, the inclusions or contain errors. If a metal layer of relatively low density is driven forward at a relatively large starting angle and process conditions such that the beam oscillates, a perfect connection is obtained.

In addition to solving the problem of how to use the explosive plating for flawless angle arrangement To perform connection, the inventive method still has the unexpected advantage that when using relatively large angles it is possible to establish direct metal-metal bonds with essentially no alloy formation (or intermetallic mixtures) in the joint surface receive. In certain metal constructions, this absence of alloys is extraordinary Importance.

For example

A plate of carbon steel, 152.4 228.6 χ 19 mm, was supported on a sheet of plywood and a 3.175 mm thick, equally sized plate of corrosion-resistant steel (US Specification 304) was placed on the steel plate via spot-welded steel spacers. The plates were arranged in such a way that a minimum distance of 1.27 mm between the facing 152.4 mm edges was maintained, ie they met in the imaginary extension at an angle δ of 10 °. The outer surface of the steel plate was covered with a 25.4 mm thick layer of polystyrene foam as a buffer and an explosive layer (explosive charge 0.775 g / cm ² ) was placed on it. The explosive layer was a flexible mass of 72% pentaerythritol tetranitrate, 6.5% nitrocellulose and 21.5% tri- (2 - ethylhexyl) - 2 - acetoxy -1,2,3 - propane tricarboxylate with a detonation speed of about 6900 m / sec. It was ignited in the middle with a detonator (Fig. 4E). After detonation, the plates were connected over the entire contact surface by an essentially uninterrupted metallurgical bond.

The collision speed V _{c was} calculated as follows:

D = 6,900 m / sec
Y = 4.2 °
δ = 10 °

V = D + = 4900 m / sec. ^c sin (γ - δ) '

This experiment involved the conditions of the combination from FIG. 4 E with FIG. 5. The explosive layer 5 is detonated above this in the middle by a detonator 6. The F i g. 5 can therefore be used exactly for the upper part of the system, ie above the capsule. In order to take into account the lower part of the system, i.e. below the detonator, in other words: more at point O, the arrow above the line OZ must be reversed, since in this case the detonation from the detonator advances towards point O. In this case, the one shown in FIG. 5 indicated angle y _x the angle γ and has an amount of 4.2 °.

Since the detonation runs against the imaginary line of intersection of the plane of the plate, the angle λ is negative. The calculated collision speed V _c is:

greater than the speed of sound Cl, C 2 4500 m / sec, but not more than 20% (that would be 5400 m / sec).

The maximum bending angle on one of the steel plates (Φχ, Φ ₂ ) caused by the shock wave at a collision speed of around 4900 m / sec could be determined to be around 0.6 °. The sum of the bending angles Φ of the two plates is therefore 1.2 °.

The collision angle Ψ = (10-4.2) is thus 5.8 ° and is thus above the bends in the steel plates caused by the shock wave. This applies to the lower part of the system, that is, between the detonator and point O (Fig. 5), so that due to the reverse direction of progress: the detonation, this angle can be regarded as negative. The collision angle Ψ in the upper; Area, i.e. between the primer and point Z, differs from Ψ, since in this case γ is to be added (10 + 4.2 °). So Ψ 'is 14.2

B is ρ ie 1 2 45

An explosive with a detonation speed D = 3275 m / sec at an initial angle of 0 = 4 ° and an angle γ = 17 ° was used for the explosive plating. A 3.175 mm thick titanium plate PI was plated on a 12.7 mm thick plate made of carbon steel PI. Both plates had dimensions of 17.8 × 22.9 cm.

The speed of sound Cl in titanium entered.

4800 m / sec and C 2 in carbon steel 4500 m / be In this system titanium is there with 4800 m / sec Metal of the highest speed of sound. 120 °, of which 5760 m / sec are calculated.

The two plates were spaced about 6.35 mm apart. Out

D = 3275 m / sec

Vc = 3275 +.
^c si

= 2610 m / sec

sin (γ + δ)
the result is a collision speed V _{c vc}

15 16

2610 m / sec. This collision speed is D = 6900 m / sec

the range according to the invention. The plating obtained was excellent. 7 = 17 °

₅ «5 = 3

Comparison ·

In a modification of Example 2, a ^V c ~ ⁶⁹⁰⁰ + _{sin (} + _ό) = 59O ° ^m / ^{sec explosive layer was used} with a detonation speed that is outside the inventive collision speed V _c of 5900 m / sec range. The other process conditions io and is thus significantly higher than 120% of the sounds were kept the same. At a detonation speed of titanium.

speed of 6900 m / sec (pentaerythritol tetrani- In these process conditions no

stepped) and an angle δ of 3 ° results from plating can be achieved.

1 sheet of drawings

Claims (1)

Claim: A method for producing an essentially continuous metallurgical connection between two metal plates with the aid of explosive force, in that the two metal plates are arranged at an angle of 1 to 60 ° to one another, a layer of a detonating explosive is applied to at least one of the metal plates and this is ignited, characterized in that that one uses an explosive layer with such an explosive weight per unit area that during the detonation the collision pressure exceeds the elastic limit of the metal with the lowest elastic limit in the system and at least one of the ratios of the collision velocity to the speed of sound in the metal layers V _c : C <1.2 is with the proviso that - if the ratio of each collision speed to the speed of sound of the corresponding metal layer 1 < V _c : C < 1.2, so that, according to the laws of fluid mechanics, oblique shock waves occur which cause a flow rate effect, which is expressed in the plates as a bend with the angles 0 _U Φ> ₂ - the collision angle Ψ between the two metal parts in the collision area exceeds the maximum value Φ of the total bends ((P ₁ + Φ ₂ ).