EP0586481B1 - Method and device for obtaining an iron-based amorphous metal alloy wire - Google Patents

Abstract

Method and device for obtaining an iron-based amorphous metal alloy wire (12) by providing a jet (7) of molten alloy (4) through the orifice (60) of a dye (6), and introducing said jet (7) in a cooling liquid (9) pressed by centrifugal force against the internal wall of a rotary drum. The crucible (2) containing the alloy (4) and the dye (6) are made of different materials and are joined by a seal (25) made from material different from those of the crucible (2) and of the dye (6). Furthermore, means (3) are used to heat the alloys (4) both in the crucible (2) and in the dye (6) and an inert or reducing gas is supplied directly to contact a jet (7) at the outlet of the dye (6). The wire (12) obtained using said method or device may be used, for example, for reinforcing tyre casings.

Description

The invention relates to methods and devices for obtaining wires of amorphous metal alloys by rapid cooling in a liquid medium, these alloys being based on iron.

It is known to implement this process of hyper quenching by spraying a jet of amorphizable molten alloy, based on iron, in a coolant layer, for example a layer of water, plated by centrifugal force. against the inner wall of a rotating drum. This process is commonly called "in rotating water spinning", although it is not limited to the use of water as a cooling fluid, the latter being often referred to as the abbreviated form "INROWASP", form which will be used in the continuation, given its very frequent use in the technical literature.

The INROWASP process makes it possible to obtain fine amorphous wires, very resistant to corrosion, having a tensile breaking load which can reach or even exceed 3200 MPa.

Such a process is described for example in US Patents 4,495,691 and US 4,523,626.

• il se produit une usure importante de l'orifice de coulée par lequel est filé l'alliage fondu, et ceci même après quelques minutes de coulée seulement ;
• si l'on veut réduire le nombre de ruptures du jet ou du fil trempé lors de la coulée, il est préférable d'avoir une faible valeur pour l'angle d'incidence du jet par rapport à la direction circonférentielle du liquide de refroidissement, cette valeur étant par exemple comprise entre 40 et 70° ; d'autre part, pour éviter que le jet de métal liquide ne commence à se résoudre en gouttes avant son contact avec le liquide de refroidissement, il est nécessaire que la distance entre ce liquide et l'orifice de la filière soit très faible, par exemple égale à 5 mm, ou même moins ; or ces deux conditions sont très difficiles à réaliser par suite de l'encombrement des dispositifs servant à chauffer l'alliage et à le filer ;
• pour certaines compositions, l'oxydation du jet liquide est très rapide, à l'instant où il sort de la filière ; cette oxydation conduit à un mouillage important de la partie extérieure de la filière par l'oxyde formé, entraînant des perturbations au niveau de l'écoulement, et, par suite, à des ruptures fréquentes du jet et du fil, et ceci même pour une faible distance entre la sortie de filière et le liquide réfrigérant ;
• les problèmes d'encombrement précités, et la nécessité d'avoir une distance faible entre l'orifice de coulée et le liquide réfrigérant font qu'il est très difficile de chauffer efficacement le métal liquide au niveau de l'orifice de coulée ; il est alors nécessaire de provoquer une surchauffe de l'alliage liquide, avant son passage dans la filière, pour qu'il reste liquide lors de la projection, mais cette surchauffe peut provoquer des instabilités du jet de nature hydrodynamique, et conduire à un mauvais état de surface du fil obtenu après trempe, ou même à un fil plus sensible à la fragilisation thermique.

However, this process currently has the following drawbacks:

• there is significant wear of the pouring orifice through which the molten alloy is spun, and this even after only a few minutes of casting;
• if it is desired to reduce the number of ruptures of the jet or of the wire quenched during casting, it is preferable to have a low value for the angle of incidence of the jet relative to the circumferential direction of the coolant, this value being for example between 40 and 70 °; on the other hand, to prevent the jet of liquid metal from starting to resolve into drops before it comes into contact with the coolant, it is necessary that the distance between this liquid and the orifice of the die is very small, by example equal to 5 mm, or even less; however, these two conditions are very difficult to achieve owing to the size of the devices used to heat the alloy and to spin it;
• for certain compositions, the oxidation of the liquid jet is very rapid, the instant it leaves the die; this oxidation leads to significant wetting of the external part of the die by the oxide formed, causing disturbances at the level of the flow, and, consequently, to frequent ruptures of the jet and of the wire, and this even for a short distance between the die outlet and the coolant;
• the aforementioned size problems, and the need to have a small distance between the pouring orifice and the coolant make it very difficult to efficiently heat the liquid metal at the pouring orifice; it is then necessary to cause an overheating of the liquid alloy, before it passes through the die, so that it remains liquid during projection, but this overheating can cause instabilities of the jet of hydrodynamic nature, and lead to poor surface condition of the wire obtained after quenching, or even a wire more sensitive to thermal embrittlement.

Japanese patent application published under number 63-10044 describes a process in which an inert or slightly reducing protective gas is introduced into an envelope surrounding the casting crucible. However, this protective casing leads to a large bulk, which does not allow the casting orifice to be efficiently heated, and it is therefore not possible to avoid overheating of the amorphizable alloy. On the other hand, the protective gas is not located at the level of the pouring orifice and the protection of the jet is then not satisfactory.

Japanese patent application published under No. 1-271040 describes a process in which the heating of the amorphizable alloy in the upper part of the crucible is carried out using a first induction coil supplied with medium frequency current. , and the heating at the bottom of the crucible is provided by a second induction coil supplied with high frequency current. This device is characterized by a great complexity of the heating means, the proximity of the two induction circuits at different frequencies can also cause undesirable effects in the generators due to a phenomenon of coupling between the two circuits.

The object of the invention is to avoid these drawbacks.

• a) on utilise un creuset contenant l'alliage et une filière disposée à une des extrémités du creuset ; le creuset et la filière sont réalisés avec des matières différentes et sont réunis par un joint dont la matière est différente de celles du creuset et de la filière ;
• b) on utilise des moyens qui sont les mêmes pour chauffer l'alliage à la fois dans le creuset et dans la filière ;
• c) on fait arriver un gaz inerte ou réducteur dans une chambre localisée à proximité de la filière, directement au contact du jet à sa sortie de la filière.

Consequently, the invention relates to a method for obtaining a wire of amorphous metallic alloy based on iron, this method consisting in producing a jet of a meltable amorphous alloy through the orifice of a die and in introducing the jet into a coolant pressed by centrifugal force against the inner wall of a drum rotary, this process being characterized by the following points:

• a) using a crucible containing the alloy and a die arranged at one end of the crucible; the crucible and the die are made with different materials and are joined by a seal whose material is different from those of the crucible and the die;
• b) using the same means to heat the alloy both in the crucible and in the die;
• c) an inert or reducing gas is brought into a chamber located near the die, directly in contact with the jet at its exit from the die.

• a) le creuset et la filière sont réalisés avec des matières différentes et sont réunis par un joint dont la matière est différente de celles du creuset et de la filière ;
• b) le dispositif comporte des moyens qui sont les mêmes pour chauffer l'alliage à la fois dans le creuset et dans la filière ;
• c) le dispositif comporte des moyens pour faire arriver un gaz inerte ou réducteur dans une chambre localisée à proximité de la filière, directement au contact du jet à sa sortie de la filière.

The invention also relates to a device for obtaining a wire of amorphous metal alloy based on iron, this device comprising a crucible capable of containing an amorphizable alloy in the liquid state, based on iron, a die arranged at one end of the crucible , means for applying pressure to cause the liquid alloy to flow through the orifice of the die, in the form of a jet, in the direction of a coolant, a drum, and means for making turn the drum around an axis so as to press the coolant in the form of a layer against the internal wall of the drum, so as to give the amorphous wire by rapid solidification of the jet, the device being characterized by the following points :

• a) the crucible and the die are made with different materials and are joined by a seal whose material is different from those of the crucible and the die;
• b) the device comprises means which are the same for heating the alloy both in the crucible and in the die;
• c) the device comprises means for causing an inert or reducing gas to arrive in a chamber located near the die, directly in contact with the jet at its exit from the die.

This wire can be used, for example, to reinforce plastic or rubber articles, in particular tire casings, and the invention also relates to these articles.

The examples of embodiment which follow, as well as the diagrammatic figures of the drawing corresponding to these examples, are intended to illustrate the invention and to facilitate understanding without however limiting its scope.

• La figure 1 représente un dispositif conforme à l'invention, avec un tambour rotatif, selon une coupe effectuée dans un plan perpendiculaire à l'axe du tambour ;
• La figure 2 représente le dispositif de la figure 1 selon une coupe effectuée dans un plan contenant l'axe au tambour ;
• La figure 3 représente plus en détail une portion du dispositif représenté aux figures 1 et 2, avec une portion du creuset et la filière utilisés dans ce dispositif, selon une coupe effectuée dans un plan contenant l'axe du creuset et de la filière et perpendiculaire à l'axe du tambour ;
• La figure 4 représente une portion d'un autre dispositif conforme à l'invention, cette figure étant une coupe analogue à celle de la figure 3.

On the drawing :

• Figure 1 shows a device according to the invention, with a rotary drum, in a section made in a plane perpendicular to the axis of the drum;
• Figure 2 shows the device of Figure 1 according to a section made in a plane containing the axis to the drum;
• Figure 3 shows in more detail a portion of the device shown in Figures 1 and 2, with a portion of the crucible and the die used in this device, according to a cut made in a plane containing the axis of the crucible and the die and perpendicular to the axis of the drum;
• FIG. 4 represents a portion of another device according to the invention, this figure being a section similar to that of FIG. 3.

Figures 1 and 2 show a device 1 according to the invention for producing amorphous metal wires in iron-based alloys. This device 1 includes a crucible 2 around which is located the induction coil 3 which makes it possible to melt the amorphizable metallic alloy 4 based on iron placed in the crucible 2, a pressurized gas 5, for example helium, allowing the liquid alloy 4 to flow through the orifice 60 of the die 6 so as to obtain a jet 7, this gas 5 being inert with respect to the alloy 4.

This jet 7 directed, for example downwards, reaches the layer 8 of coolant 9, this layer being pressed against the internal wall 10 of the drum 11, this liquid 9 being for example water. The jet 7 then solidifies very quickly to give the amorphous metallic wire 12.

The drum 11 actuated by the motor 13 rotates around its axis in the direction of the arrow F ₁₁ , this axis being referenced xx 'in Figure 2 and x in Figure 1. The centrifugal force thus obtained applies the liquid 9 in the form of the regular cylindrical layer 8 against the internal wall 10, as previously indicated. Figure 1 is a section taken along a plane perpendicular to the axis xx ', and Figure 2 is a section taken along a plane passing through the axis xx', this plane being referenced by the straight line segments II-II in Figure 1.

Figure 3 shows in more detail a portion 14 of the device 1, Figure 3 being a section similar to that of Figure 1, and therefore perpendicular to the axis xx '. This portion 14 shows the lower part of the crucible 2, the die 6 with its orifice 60, and the lower turns of the coil 3, as well as the free surface 80 of the liquid layer 8.

The crucible 2 comprises an upper cylindrical part 2A, an intermediate part 2B forming a cone portion, and a lower part 2C also in the form of a cone, terminated by a 2D conical bevelled face which defines an opening 21 at its lower part.

The crucible 2 has an axis of revolution, referenced yy ', for example vertical, which is also the axis of revolution of the die 6 and its orifice 60, this axis yy' being included in the plane of Figure 3. L he thickness of the crucible 2 is practically constant for the parts 2A, 2B and the thickness of the part 2C corresponding to the bevelled 2D face decreases downwards. The angles of the conical parts 2B, 2C measured at the external surface of the crucible 2 are referenced respectively α2B, α2C. The angle of the 2D conical face is referenced α2D. The jet 7 flows downwards, along the axis yy ', from the orifice 60, through the opening 21, in the direction of the surface 80 of the layer 8, this flow being shown diagrammatically by the arrow F7, and it makes the acute angle α7 with the surface 80, in the plane of FIG. 3, this surface 80 being driven by a rotational movement, shown diagrammatically by the arrow F8. The arrows F7, F8 are located in the plane of FIG. 3 and they form between them the angle α7 which is the angle of incidence of the jet 7 relative to the circumferential direction of rotation of the liquid 9. The face upper 6A of the die 6 is planar and forms a crown, and the lower face 6B of the die 6 is also planar, being pierced with the orifice 60.

The die 6 is arranged inside the conical part 2C of the crucible. A portion of the internal face of the part 2C, referenced 20C, the downstream lower end face 6B of the die 6 where the orifice 60 and the opening 21 are located define a chamber 22 into which opens a thin tube 23 passing through the face 2D beveled. During the casting of the alloy 4, a neutral or reducing gas 24 is made to come through the tube 23. This gas 24 fills the chamber 22, being in contact with the face 6B and therefore the jet 7, at its outlet from the orifice 60. The gas 24 flows slowly out of the chamber 22 through the opening 21. The gas 24 can for example be nitrogen, argon, hydrogen, ammonia cracked, hydrogen or a mixture containing hydrogen being preferred, pure hydrogen being even more preferable.

A seal 25 sandwiched between the die 6 and the crucible 2 seals between these two parts. The die 6 and the crucible 2 are made with different materials making it possible to meet the different requirements for the die 6 and the crucible 2. The material of the seal 25 is different from the materials used for the die 6 and the crucible 2.

The coil 3 is formed by a single spiral winding around the axis yy 'of a thin copper tube 30, internally cooled by circulation of water, forming turns 30A which are inclined relative to the axis yy '(Figures 2 and 3) and which follow at a short distance the conical parts 2B, 2C and the cylinder 2A. For the simplicity of the drawing, only four turns 30A are shown in FIG. 3. The turn 30A lower, that is to say the one closest to the surface 80, is for example situated practically in a plane parallel to the surface portion 80 which faces it, this lower turn descending at the level of the orifice 60, following the yy 'axis. The chamber 22 is small compared to the crucible 2 and the die 6.

The 2D bevelled face of the lower part 2C makes it possible to have a low height for the chamber 22 and a small distance between the orifice 60 and the surface 80. The angle α2D of this 2D beveled face is for example equal to twice the angle α7 or close to twice the angle α7, for this purpose.

The opening 21 preferably has a diameter of between 1 mm and 2 mm.

• a) L'utilisation de matières différentes pour le creuset 2 et la filière 6 permet de répondre aux diverses exigences posées par ces éléments.
  • Le creuset 2, étant donné son volume, doit être réalisé avec une matière dont le coût ne soit pas élevé, et qui permette de résister aux chocs thermiques et à de forts gradients thermiques, tout en étant inerte vis-à-vis de l'alliage liquide. Une telle matière est par exemple la silice vitreuse, le creuset étant réalisé notamment par étirage à chaud.
  • La filière 6 doit être très inerte vis-à-vis de l'alliage liquide, c'est-à-dire qu'elle doit résister à une érosion mécanique due à l'alliage liquide, donc à sa dissolution dans cet alliage, et qu'elle doit d'autre part résister à la réduction par les éléments actifs de l'alliage liquide. Pour des alliages amorphisables à forte teneur en silicium et en bore, ce qui est un cas fréquent, la matière de la filière peut être par exemple une zircone stabilisée sous forme cubique, notamment une zircone stabilisée avec au moins un des composés suivants : oxyde d'yttrium, magnésie, chaux, ce qui garantit ainsi une longue période d'utilisation. Il est d'autre part possible de réaliser la filière par moulage et frittage de façon à assurer une parfaite reproductibilité de son profil intérieur.
  • Ces matières étant de natures différentes, il est nécessaire de les réunir par un joint 25 qui peut être réalisé avec une matière suffisamment fluide à la température de travail pour encaisser les problèmes de dilatation différentielle entre le creuset 2 et la filière 6, mais suffisamment visqueuse à la température de travail pour assurer l'étanchéité vis-à-vis de l'alliage 4 liquide sous pression. La matière du joint 25 est par exemple une poudre constituée par un mélange de silice et d'oxyde de bore.
• b) La forme générale de la portion 14 de coulée, avec l'encastrement de la filière 6 à la partie inférieure du creuset 2, permet d'obtenir simultanément les avantages suivants :
  • . il est possible de chauffer la filière 6 au niveau même de l'orifice 60, ce qui permet d'éviter une surchauffe de l'alliage 4 ;
  • . la distance parcourue par le jet 7 entre l'orifice 60 et la surface 80 du liquide 9 peut être faible, de préférence au plus égale à 15 mm, et avantageusement au plus égale à 5 mm, cette distance étant au minimum égale à 2 mm, la présence du gaz protecteur 24 permettant cependant plus de souplesse pour le réglage de cette distance que s'il n'y avait pas ce gaz. Cette faible distance évite tout début de résolution du jet en gouttes et ceci tout en permettant de travailler si on le désire avec une valeur relativement faible pour l'angle α7, ce qui garantit souvent une bonne continuité du fil 12. La valeur de α7 est de préférence comprise entre 40° et 90°, cette valeur étant plus préférentiellement comprise entre 50° et 70°.
  • . la localisation du gaz 24 au contact de la filière 6, autour de l'orifice 60 et du jet 7, permet de protéger efficacement la face 6B de la filière 6 contre un mouillage par l'oxyde qui se formerait sur le jet 7 en l'absence de cette protection, et donc d'augmenter sa durée de vie, tout en évitant l'oxydation de l'alliage 4 du jet 7, et ceci avec un débit très faible de gaz 24. De préférence ce débit est compris entre 0,5 cm³/s et 5 cm³/s.
• c) Toutes ces caractéristiques ont l'avantage de permettre l'utilisation d'alliages 4 amorphisables riches en fer, c'est-à-dire économiques et donnant des fils très résistants, alors que de tels alliages n'étaient pas utilisables jusqu'ici.

The invention allows the following advantages:

• a) The use of different materials for the crucible 2 and the die 6 makes it possible to meet the various requirements posed by these elements.
  • The crucible 2, given its volume, must be made of a material whose cost is not high, and which makes it possible to withstand thermal shocks and strong thermal gradients, while being inert with respect to the liquid alloy. Such a material is for example vitreous silica, the crucible being produced in particular by hot drawing.
  • The die 6 must be very inert with respect to the liquid alloy, that is to say that it must resist mechanical erosion due to the liquid alloy, therefore to its dissolution in this alloy, and that it must on the other hand resist reduction by the active elements of the liquid alloy. For amorphizable alloys with a high silicon and boron content, which is a frequent case, the material of the die can be, for example, a zirconia stabilized in cubic form, in particular a zirconia stabilized with at least one of the following compounds: oxide of 'yttrium, magnesia, lime, which guarantees a long period of use. It is also possible to produce the die by molding and sintering so as to ensure perfect reproducibility of its internal profile.
  • These materials being of different natures, it is necessary to join them by a joint 25 which can be produced with a material sufficiently fluid at the working temperature to absorb the problems of differential expansion between the crucible 2 and the die 6, but sufficiently viscous at working temperature to ensure sealing against alloy 4 liquid under pressure. The material of the seal 25 is for example a powder constituted by a mixture of silica and boron oxide.
• b) The general shape of the portion 14 of casting, with the embedding of the die 6 at the bottom of the crucible 2, makes it possible to simultaneously obtain the following advantages:
  • . it is possible to heat the die 6 at the same level as the orifice 60, which makes it possible to avoid overheating of the alloy 4;
  • . the distance traveled by the jet 7 between the orifice 60 and the surface 80 of the liquid 9 may be small, preferably at most equal to 15 mm, and advantageously at more equal to 5 mm, this distance being at least equal to 2 mm, the presence of the protective gas 24 allowing however more flexibility for the adjustment of this distance than if there were not this gas. This small distance avoids any start of resolution of the jet in drops and this while making it possible to work if desired with a relatively small value for the angle α7, which often guarantees good continuity of the wire 12. The value of α7 is preferably between 40 ° and 90 °, this value being more preferably between 50 ° and 70 °.
  • . the location of the gas 24 in contact with the die 6, around the orifice 60 and the jet 7, makes it possible to effectively protect the face 6B of the die 6 against wetting by the oxide which would form on the jet 7 in l absence of this protection, and therefore to increase its lifespan, while avoiding the oxidation of the alloy 4 of the jet 7, and this with a very low gas flow rate 24. Preferably this flow rate is between 0 , 5 cm ³ / s and 5 cm ³ / s.
• c) All these characteristics have the advantage of allowing the use of amorphizable alloys 4 rich in iron, that is to say economical and giving very resistant wires, whereas such alloys were not usable until here.

Preferably, the alloy 4 corresponds to the formula Fe _α Cr _β Si _γ B _δ Ni _ε Co _ζ Mo _η , this alloy being devoid of other elements, if not unavoidable impurities.

α, β, γ, δ, ε, ζ, η are the atomic percentages of the elements to which they relate, these percentages checking the following relationships: $$\text{α ≧ 55; 5 ≦ β ≦ 10; 7.5 ≦ γ ≦ 15; 8 ≦ δ ≦ 15; 0 ≦ ε + ζ ≦ 15; 0 ≦ η ≦ 2.}$$

Even more preferably, we have at least one of the relationships: $$\text{α ≧ 60; 5 ≦ β ≦ 7; 0 ≦ ε + ζ ≦ 10.}$$

This alloy therefore has a very high iron content since it is greater than 60% (atomic%). These alloys are economical, and the invention makes it possible to use them to produce large lengths of amorphous wires, without breakage, these wires having advantageous mechanical properties, while known methods did not allow them to be used because they led to breakages. frequent and to wires with poor mechanical properties.

Examples

• diamètre intérieur du tambour 11 : 470 mm ;
• fluide 9 utilisé : eau ; épaisseur de la couche 8 : 20 mm ; température de l'eau : 5°C ; la surface 80 de la couche 8 est à la pression atmosphérique ;
• angle α7 : 52° ;
• gaz 5 : hélium, pression de ce gaz : 4,5 bars (450 000 Pa) ;
• distance entre l'orifice 60 de la filière 6 et la surface libre 80 en suivant l'axe yy' : 3 mm ;
• gaz 24 de protection : hydrogène ; débit de ce gaz 24 à une pression de 1 bar et à la température ambiante (environ 20°C), 2,22 cm³/s, soit une vitesse de 280 cm/s dans le tube 23 ;
• creuset 2 réalisé en silice vitreuse transparente ; épaisseur du creuset 2 dans les parties 2A, 2B et 2C (avant la face biseautée 2D), environ 3 mm; angle α2B : environ 90° ; angle α2C : environ 35° ; angle α2D : environ 120° ;
• filière 6 réalisée en zircone stabilisée à l'oxyde d'yttrium par technique de moulage par compression uniaxiale et de frittage, épaisseur de cette filière : environ 1 mm ; hauteur selon l'axe yy' : environ 5 mm ; cette filière a intérieurement et extérieurement la forme d'un cône dont l'angle (non référencé) est égal à α2C, soit environ 35° ;
• joint 25 réalisé avec un mélange de silice et d'oxyde de bore ;
• hauteur de la chambre 22 selon l'axe yy' : environ 2 mm ; diamètre de l'ouverture 21 : environ 1 mm.

In the two examples according to the invention which follow, the device 1 is used to produce amorphous wires 12 using two amorphous alloys. For the realization of these two examples, the device 1 has the following characteristics:

• inner diameter of the drum 11: 470 mm;
• fluid 9 used: water; layer 8 thickness: 20 mm; water temperature: 5 ° C; the surface 80 of the layer 8 is at atmospheric pressure;
• angle α7: 52 °;
• gas 5: helium, pressure of this gas: 4.5 bars (450,000 Pa);
• distance between the orifice 60 of the die 6 and the free surface 80 along the axis yy ': 3 mm;
• protective gas 24: hydrogen; flow rate of this gas 24 at a pressure of 1 bar and at room temperature (about 20 ° C), 2.22 cm ³ / s, ie a speed of 280 cm / s in the tube 23;
• crucible 2 made of transparent vitreous silica; thickness of crucible 2 in parts 2A, 2B and 2C (before the bevelled face 2D), approximately 3 mm; angle α2B: approximately 90 °; angle α2C: approximately 35 °; angle α2D: approximately 120 °;
• die 6 made of zirconia stabilized with yttrium oxide by uniaxial compression molding and sintering technique, thickness of this die: about 1 mm; height along the axis yy ': about 5 mm; this die has internally and externally the shape of a cone whose angle (not referenced) is equal to α2C, or about 35 °;
• joint 25 produced with a mixture of silica and boron oxide;
• height of the chamber 22 along the axis yy ': approximately 2 mm; diameter of the opening 21: about 1 mm.

Example 1

An amorphizable alloy of composition is used

Fe ₆₁ Co ₁₀ Cr ₇ Si ₉ B ₁₃

the subscript figures giving the atomic%.

• température de l'alliage liquide : 1250°C ;
• diamètre de l'orifice 60 : 110 µm ;
• vitesse linéaire de la paroi interne 10 du tambour 11 : 9,04 m/s.

The spinning is carried out under the following conditions:

• liquid alloy temperature: 1250 ° C;
• orifice 60 diameter: 110 µm;
• linear speed of the internal wall 10 of the drum 11: 9.04 m / s.

A continuous length of 1760 m of amorphous wire 12 is obtained, having a diameter of 98 μm and an average tensile breaking load, in the quenched raw state, of 3237 MPa with a standard deviation of 59.

Example 2

An amorphizable alloy of composition is used

Fe ₇₁ Cr ₇ Si ₉ B ₁₃

the subscript figures giving the atomic%.

• température de l'alliage liquide : 1260°C ;
• diamètre de l'orifice 60 : 118 µm ;
• vitesse linéaire de la paroi interne 10 du tambour 11 : 9,33 m/s.

The spinning is carried out under the following conditions:

• liquid alloy temperature: 1260 ° C;
• orifice 60 diameter: 118 µm;
• linear speed of the internal wall 10 of the drum 11: 9.33 m / s.

A continuous length of 1145 m of amorphous wire 12 is obtained, having a diameter of 109 μm and an average tensile breaking load, in the quenched raw state, of 3219 MPa with a standard deviation of 38.

Figure 4 shows a portion of another device 40 according to the invention. This device 40 is similar to the device 1 with the following differences. In this device 40 the crucible 41 comprises a cylindrical upper part 41A, similar to the part 2A of the device 1. This part 41A is extended downwards by a conical part 41B whose lower end has a beveled face 41C also conical. The angles of the cones of the part 41B and of the face 41C are represented respectively by α41B and α41C.

The die 42 has a shape similar to the die 6 of the device 1 but it is located in the lower portion of the part 41B so that its orifice 420 is located outside and below the crucible 41, the die 42 forming thus protruding from the conical part 41B, outside the crucible 41.

The part of the die 42 which is located under the part 41B of the crucible 41 is surrounded by a ring 44 pierced with a hole 45 into which the tube 43 opens, where the gas 24 arrives in the ring 44. This ring 44 has by example externally the shape of a cylinder portion whose upper end 46 is fixed in sealed manner to the bevelled face 41C by surrounding the orifice 420, while its lower end 47 is practically parallel to the surface portion 80 which faces, and a short distance from that portion. In this arrangement, the angle α41B is for example smaller than the angle α2B of the device 1.

The device 40 makes it possible to locate the gas 24 around the lower part of the die 42 against the orifice 420, and around the jet 7, in the chamber formed by the internal face of the ring 44 and by the surface portions 41C and of die 42 which it surrounds.

The material of the ring 44 may for example be the same as that of the crucible 41.

Of course, the invention is not limited to the examples described above. Thus, for example, the geometric characteristics given above, in particular for the angles and the thicknesses of the crucible 2 and of the die 6, can vary within wide limits.

Claims (28)

1. A process for obtaining a wire (12) made of iron-based amorphous metal alloy, this process consisting in producing a jet (7) of a molten amorphisable alloy (4) through the orifice (60, 420) of a die (6, 42) and introducing the jet (7) into a cooling liquid (9) urged by centrifugal force against the inner wall (10) of a rotary drum (11), this process being characterised by the following points:

   a) a crucible (2, 41) containing the alloy (4) and a die (6, 42) arranged at one of the ends of the crucible are used; the crucible (2, 41) and the die (6, 42) are made of different materials and are joined by a joint (25) the material of which differs from those of the crucible (2, 41) and of the die (6, 42);

   b) means (3) for heating the alloy (4) which are identical are used both in the crucible (2, 41) and in the die (6, 42);

   c) an inert or reducing gas (24) is delivered into a chamber (22) located close to the die (6, 42), directly in contact with the jet as it leaves the die (6, 42).
2. A process according to Claim 1, characterised in that the crucible (2, 41) comprises at least one conical part (2C, 41B) with an opening (21) through which the jet (7) passes, the die being arranged at least partly in this conical part.
3. A process according to Claim 2, characterised in that the die (6) is arranged entirely in the conical part (2C), this conical part and the downstream outermost face (6B) of the die, where the orifice (60) of the latter is situated, defining a chamber (22) into which there emerges a tube (23) through which the gas (24) is delivered into the chamber (22), this chamber comprising an opening (21) through which the jet (7) passes, in the direction of the cooling liquid (9).
4. A process according to Claim 2, characterised in that the die (42) is arranged only partly in the conical part (41B) and projects, with its orifice, out of this conical part, outside the crucible (41); a tube (43) enabling the gas (24) to be delivered directly in contact with the jet (7), as it leaves the die (42), emerges into a chamber surrounding the orifice of the die, this chamber comprising an opening through which the jet passes in the direction of the cooling liquid.
5. A process according to any one of Claims 1 to 4, characterised in that the crucible (2, 41) is made of vitreous silica.
6. A process according to any one of Claims 1 to 5, characterised in that the die (6, 42) is made of zirconia stabilised in cubic form.
7. A process according to Claim 6, characterised in that the die (6, 42) is made of zirconia stabilised with at least one of the following compounds: yttrium oxide, magnesia, lime.
8. A process according to any one of Claims 1 to 7, characterised in that the joint (25) is made using a mixture of silica and boron oxide.
9. A process according to Claim 4, characterised in that the chamber is made partly using vitreous silica.
10. A process according to any one of Claims 1 to 9, characterised in that an alloy (4) of formula Fe_αCr_βSi_γB_δNi_εCo_ζMo_η is used, α, β, γ, δ, ε, ζ, and η being the atomic percentages of the elements to which they refer, these percentages having the following relationships: $$\text{α ≧ 55; 5 ≦ β ≦ 10; 7.5 ≦ γ ≦ 15; 8 ≦ δ ≦ 15; 0 ≦ ε + ζ ≦ 15; 0 ≦ η ≦ 2.}$$

    
11. A process according to Claim 10, characterised in that there is at least one of the relationships: $$\text{α ≧ 60; 5 ≦ β ≦ 7 ; 0 ≦ ε + ζ ≦ 10.}$$

    
12. A process according to any one of Claims 1 to 11, characterised in that the distance covered by the jet (7) between the orifice (60, 420) of the die (6, 42) and the cooling liquid (9) is at least 2 mm and at most 15 mm.
13. A process according to Claim 12, characterised in that this distance is at least 2 mm and at most 5 mm.
14. A process according to any one of Claims 1 to 13, characterised in that the contact of the jet (7) with the cooling liquid (9) takes place at an angle of incidence (α7) of between 40° and 90° in relation to the circumferential direction of rotation of the liquid.
15. A process according to Claim 14, characterised in that this angle of incidence (α7) is between 50° and 70°.
16. A device (1, 40) for obtaining a wire (12) made of iron-based amorphous metal alloy, this device (1, 40) comprising a crucible (2, 41) capable of containing an iron-based amorphisable alloy (4) in the liquid state, a die (6, 42) arranged at one end of the crucible (2, 41), means (5) enabling a pressure to be applied to make the liquid alloy (4) flow through the orifice (60, 420) of the die (6, 42), in the form of a jet (7), in the direction of a cooling liquid (9), a drum (11), and means (13) enabling the drum (11) to be rotated about an axis (x, x') so as to urge the cooling liquid (9) in the form of a layer (8) against the inner wall (10) of the drum (11), so as to produce the amorphous wire (12) by rapid solidification of the jet (7), the device being characterised by the following points:

    a) the crucible (2, 41) and the die (6, 42) are produced using different materials and are connected by a joint (25) the material of which differs from those of the crucible and of the die;

    b) the device (1, 40) comprises means (3) for heating the alloy (4) which are identical both in the crucible and in the die;

    c) the device comprises means (23, 43) for delivering an inert or reducing gas (24) into a chamber (22) located close to the die (6, 42) directly in contact with the jet (7) as it leaves the die (6, 42).
17. A device (1, 40) according to Claim 16, characterised in that the crucible (2, 41) comprises at least one conical part (2C, 41B) with an opening (21) through which the jet (7) passes, the die being arranged at least partly in this conical part.
18. A device (1) according to Claim 17, characterised in that the die (6) is arranged entirely in the conical part (2C), this conical part and the downstream outermost face (6B) of the die (6) where the orifice (60) of the latter is situated defining a chamber (22), the means for delivering the gas comprising a tube (23) which emerges into this chamber so as to deliver the gas (24) into the chamber (22), the chamber (22) comprising an opening (21) for the passage of the jet (7) in the direction of the cooling liquid (9).
19. A device (40) according to Claim 17, characterised in that the die (42) is arranged only partly in the conical part (41B) and projects, with its orifice, out of this conical part, outside the crucible (41), the means for delivering the gas comprising a tube (43) which emerges into a chamber surrounding the orifice (420) of the die (42), the chamber comprising an opening for the passage of the jet, in the direction of the cooling liquid.
20. A device (1, 40) according to any one of Claims 16 to 19, characterised in that the crucible (2, 41) is made of vitreous silica.
21. A device (1, 40) according to any one of Claims 16 to 20, characterised in that the die (6, 42) is made of zirconia stabilised in cubic form.
22. A device (1, 40) according to Claim 21, characterised in that the die (6, 42) is made of zirconia stabilised with at least one of the following compounds: yttrium oxide, magnesia, lime.
23. A device (1, 40) according to any one of Claims 16 to 22, characterised in that the joint (25) is a mixture of silica and boron oxide.
24. A device (40) according to Claim 19, characterised in that the chamber is partly made of vitreous silica.
25. A device (1, 40) according to any one of Claims 16 to 24, characterised in that it is arranged so that the distance capable of being covered by the jet (7) between the orifice (60, 420) of the die (6, 42) and the cooling liquid (9) is at least 2 mm and at most 15 mm.
26. A device (1, 40) according to Claim 25, characterised in that this distance is at least 2 mm and at most 5 mm.
27. A device (1, 40) according to any one of Claims 16 to 26, characterised in that it is arranged so that the contact of the jet (7) with the cooling liquid (9) takes place at an angle of incidence (α7) of between 40° and 90° in relation to the circumferential direction of rotation of the liquid.
28. A device (1, 40) according to Claim 27, characterised in that this angle of incidence (α7) is between 50 and 70°.

Images