JPH01162541A - Method and device for manufacturing metallic fiber, cross section of which take circular shape - Google Patents

Abstract

PURPOSE: To facilitate the production of a gold layer fiber having a uniformly circular cross section by forming a laminar flow within a static flow passage by the cooling liquid in a short cooling block under a nozzle and adding a resistance lowering agent to the cooling liquid. CONSTITUTION: After a shut-off valve 15 is opened, liquid 1 is admitted through the nozzle into a cooling passage 9 at a velocity of 3 to 18 m/s and is made to cross the space of a width 0.5 to 10 mm filled with gas and steam. The outflow velocity of a molten liquid material from an extruder 2 is lower by 10 to 40% than the velocity of the cooling liquid in the cooling passage 9. The jet of the molten liquid material extruded from the nozzle of the extruder 2 forms an angle of 45 to 90 deg. with the flow direction of the cooling liquid 1 in the cooling passage. The cooling liquid 1 within the short block forms the laminar flow within the static flow passage 9. When the resistance lowering agent is added to the cooling liquid 1, A Reynolds number lowers and the migration from the laminar flow to turbulence is shifted to a higher velocity. The gold layer fiber of the circular shape in the cross section of the amorphous or metastable crystalline structure having an arbitrary length and a diameter of 50 to 1000 μm is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is characterized in that an endless strand of metal melt is extruded through a spinning nozzle and cooled in an aqueous refrigerant to solidify into an endless fiber and rapidly cooled to form circular fibers. The present invention relates to a method for continuously producing thin metal fibers having a cross section. The present invention also relates to an apparatus for carrying out the method, comprising a crucible filled with a metal material and a cooling device for rapidly cooling the molten liquid metal and solidifying it into endless metal fibers.

BACKGROUND OF THE INVENTION It is known from US Pat. No. 3,845,805 and European Patent Publication No. 0,076,618 to produce metal fibers by injecting molten steel into a co-flowing liquid medium.

A closer look at these methods reveals the difficulty in controlling the coagulation process to yield fibers with uniform circular cross-sections. - in general, fibers with a uniformly circular cross section are not formed, but with a wavy structure;
Fibers with asymmetric knots, zigzag structures, stitches, corkscrew shapes, shaped spherical thickenings or very short fiber pieces are formed. Furthermore, these methods
It is only suitable for metals or metal alloys forming oxide and nitride films. The non-uniformity of the fibers is caused by the continuously varying cooling conditions of the refrigerant, which flows with little or no turbulence at the immersion point.

According to European Patent Publication No. 0 039 169, said difficulty is solved by flowing the molten alloy through a spinning nozzle into a rotating body containing a cooling liquid, forming endless fibers during cooling, which are rotated. This is overcome by winding up the inner wall of the body by the centrifugal force of the rotating body. In this method, the cooling fluid is sufficiently stationary against the wall of the rotating body so that the desired uniform cooling of the fibers is achieved and is not disturbed by turbulence.

Said method is less preferred for mass production of fibers. The process generally must be interrupted to empty the drum once it is full of fibers. It is extremely difficult to remove the fibers from the drum while it is rotating.

Occasional fiber tearing cannot be avoided.

Without the drum being stationary, it is impossible to grasp and extract the fiber incoming light.

OBJECTS OF THE INVENTION The object of the invention is therefore to provide an amorphous or quasi-shaped material with a very precise circular cross-section and a uniform diameter over its entire length and with high uniformity of cooling, depending on the particular choice of material. The object of the present invention is to provide a method and an apparatus capable of producing a large amount of metal fibers having a stable microcrystalline structure using a simple and reliable production method.

Means for Solving the Problem The above problem is accomplished by extruding a molten liquid metal material for each fiber under pressure through a nozzle, and extruding the nozzle three times.
A space of width 0.5 to 10 mm is flowed out at a speed of ~18 z/s and filled with gas and steam and subsequently below the nozzle 1.
By flowing the coolant into the coolant moving 0 to 40% faster at an angle of 45 to 90' to the flow direction of the coolant,
Any length of amorphous or metastable crystalline structure and from 50 to
In the method for manufacturing metal fibers with a circular cross section and a diameter of 1000 μm, the cooling liquid in a short cooling zone below the nozzle and in the direction of flow forms a laminar flow inside the stationary channel and the cooling liquid This problem can be solved by adding a resistance lowering agent. Further features of the method are described in claims 2-3.

As for the device, it consists of a melt container subjected to gas pressure,
One or more nozzles are provided at the bottom of the container,
a section of the liquid circuit is guided below the nozzle;
The section is filled with gas or steam from the nozzle outlet
0.5 to IOH and in which one or more reels are installed at intervals in the direction of movement of the coolant from the nozzles, in a straight horizontal line below each nozzle. Alternatively, it is solved by providing a passage which is open at the top and extends at a slight incline. Further advantageous embodiments are described in claims 5-7.

Operation and Advantage of the Invention The method and device according to the invention enable the production of metal fibers with a uniformly circular cross section.

The fibers can be solidified to glassy form on the basis of microcrystalline, partially crystalline or respectively selected alloy systems. For glassy solidification, in particular: Fe-B, Co-B, N
1-B+ Pd-3i, Fe-3i-B+ Fe-N
1-B, Nb-Ni, Cu-Ti, Fe-Zr,
Co-Zr, La-Au, Gd-C.

, Mg-Zn, Be-Zr alloys are suitable.

Fibers made of such alloys have high strength, are corrosion resistant or are distinguished by good electrical and mechanical properties.

Metallic fibers consisting of iron-based alloys with a high proportion of chromium, molybdenum or tungsten or iron containing intermetallic phases such as NiAl2 or CoFeAl2,
ζ2, which has a high elastic modulus, is superior. Such fibers can be used to produce composite materials with intentionally induced material properties, where the fibers embedded within a specific matrix improve the properties of the finished product, such as strength and Improve stiffness. Metal fibers processed into cables and nets can be used as conductive cables and as magnetic shields for electrical components. Since the properties of the metal fibers produced according to the invention can be varied widely, they can also be used for reinforcing building materials instead of glass fibers, carbon fibers and aramid fibers. They can also be used as steel cords for the reinforcement of automobile tires, as a substitute for thin high-strength metal wires produced by hot rolling, cold drawing and corresponding heat treatment of high-strength steel materials. .

Example Next, the present invention will be explained in detail with reference to illustrated embodiments.

The apparatus for carrying out the method according to the invention for producing metal fibers as shown in FIG. , a supply device (not shown in detail) for supplying helium or nitrogen, and a nozzle (not shown in detail) with one or more outlets. By applying an overpressure of inert gas above the melt level, the molten liquid material is forced through the nozzle.

Coolant 1 is pumped by pump 6 via valve 13 , heat exchanger 7 and conduit system 8 into pressurized vessel 10 . Pressure gauge 12
measures the liquid pressure in the pressurized container IO, and finely adjusts the pressure of the liquid 1 using the valve 11. After opening of the shut-off valve 15, the cooling liquid 1 flows into the cooling channel 9 via a nozzle which is not shown in detail. From the outlet end of the cooling passage 9, the cooling liquid 1 flows into the collection container 5 via the collection device,
From there, it is sent to the pressurized container 10 via the pump 6 again. A roller 14 that enters the collecting container 5 continuously winds up the metal fibers produced by the device.

The method according to the invention is carried out using the apparatus schematically illustrated in FIG. 1 as follows: Coolant 1 is pumped by pump 6 through line system 8 into pressurized container 10 . Valve 13 controls the flow rate. The coolant 1 is maintained at a temperature of 5 to 30'C by a heat exchanger 7. Pressure measuring device 12 and control valve 11 read and finely adjust the liquid pressure within pressurized vessel 10 . After opening the isolation valve 15, the liquid 1 passes through a nozzle, not shown in detail, into the cooling channel 9 at a speed of at least 3 m/s, preferably from 3 to 18 I
II/s, preferably 5 to 12 shoulder/s.

When the cooling liquid velocity decreases below 3 x/s, it becomes impossible to generate velocities higher than 10'/s in order to produce fibers with glassy or crystalline non-equilibrium structures. In order to produce thin metal fibers with a circular cross section and an amorphous or microcrystalline structure, cooling rates of 105 to 108 are required, which can be achieved with the apparatus according to the invention.

The tendency to form glass or to form crystalline metastable states within the metal fibers 3 depends, of course, on the diameter of the fibers 3, the composition of the fibers 3, the choice of the cooling liquid 1 and the temperature of the cooling liquid 1.

After the velocity state of the cooling liquid 1 in the cooling passage 9 has been stabilized, molten liquid material is injected into the cooling liquid 1 from the extrusion device. The outflow rate of the molten liquid material from the extrusion device 2 can be easily controlled via the pressure of the inert gas above the melt level and is preferably between 3 and 18 z/s, provided that should be 10-40% lower than the rate of coolant l at .

The nozzle, not shown in detail, of the extrusion device 2 has one or more outlets, which have a circular cross section and a diameter of 50 to 1000 μm, preferably 100 to 100 μm.
It is 300 μm.

The jet of the molten liquid material extruded from the nozzle of the extrusion device 2 is oriented within the cooling passage 9 at an angle of 45° to 90° with respect to the flow direction of the cooling liquid 1.
Form an angle that should take the advantageous value of 0°. The distance from the surface of the flowing cooling liquid 1 in the cooling channel 9 to the outlet of the extrusion device 2 is less than 5 zm.

The jet of molten liquid material extruded from the nozzle of the extrusion device 2 is received by a cooling liquid l in a cooling trough 9, cooled and solidified into metal fibers 3 having a circular cross section.

The thin metal fibers are continuously wound up by a fiber reel 14. The drive mechanism, bearing, and holding device of the reel 14 are as follows:
Not shown in detail. The reel 14 is washed by a flow of coolant.For a method for producing fine metal fibers and for the equipment carrying out the method, it is extremely important to control the process so that the metal fibers can be produced continuously and in high quality. It is. In this case, the most important thing is the configuration of the cooling passage 9 and the selection of the cooling liquid 1.

A preferred embodiment of the cooling channel 9 is schematically illustrated in FIG. A strand of molten liquid material is injected under pressure from the outlet nozzle 4 of the extrusion device 2 into the rapidly flowing coolant l. During the passage through the cooling channels 9, the strands of molten liquid material solidify into solid metal fibers 3. Preferably, the cross section of the cooling passage 9 has a smooth form without generating swirls in the flowing cooling liquid.

FIG. 3 shows another advantageous embodiment of the device for simultaneously producing a plurality of thin metal fibers. This embodiment includes multiple outflow nozzles 4 , one cooling trough 9 , a cooling liquid 1 and a plurality of coagulated fibers 3 . The cooling trough 9 is preferably configured such that each strand of molten liquid material exiting the outlet nozzle 4 can solidify into metal fibers 3 independently of other strands. This configuration is
It has the advantage that in the molten liquid state no undesired contact of the strands, which would lead to adhesion of the fibers 3 to each other, can take place and that the metal fibers 3 can be wound up separately on one reel 14 or on several reels.

In order to produce high-quality endless metal fibers with a circular cross section from a strand of molten liquid material, it is chosen to flow without turbulence even at high refrigerant velocities and to have a high evaporation temperature and enthalpy of evaporation. Furthermore, the refrigerant should not undergo chemical reactions with the molten liquid material or the metal fibers. Furthermore, it should be non-flammable and have good thermal conductivity.

Water is such a suitable refrigerant, although it tends to produce turbulence and instability at high flow rates. This should be avoided unconditionally. Adding a suitable drag reducing agent to water lowers the Reynolds number and shifts the transition from laminar to turbulent flow to higher speeds. Water with an equal mixture of sodium salicylate and tetradecyltrimethylammonium bromide has been found to be particularly suitable.

The cooling liquid satisfies all requirements. The effectiveness of the cooling fluid in the pump 6 is not adversely affected by mechanical loads. The flow in this case takes place in a multilayered manner, even at the required high flow rates.

■In the examples, alloys: Feal, sBt+, sS
A metal fiber consisting of i+ was produced. Its melting point is 1530
It was. The molten alloy was heated to a diameter of 180 μm with argon.
into the cooling passage at an angle of 75° from a nozzle with
A mixture of water, sodium salicylate and tetradecyltrimethylammonium bromide at a temperature of 20° C. is passed through the cooling passage.
The mixture was flowed at a speed of L2 m/s. The distance from the nozzle outlet to the refrigerant surface was 2 mm. The achieved outflow velocity of the molten liquid material exiting the nozzle is low/s
Met. The thin metal fibers produced in this way had a circular cross section with an average diameter of 150±7 μm. The maximum tensile strength was 3200 MPa. An amorphous structure could be confirmed by X-ray diffraction.

[Brief explanation of the drawing]

1 is a schematic diagram of an apparatus for carrying out the method according to the invention; FIG. 2 is a diagrammatic perspective view of an advantageous embodiment of a cooling trough section; and FIG. 1 is a schematic perspective view of one embodiment of the apparatus of FIG.

Claims (1)

[Claims] 1. A molten liquid metal material is applied to each fiber (3) through a nozzle (4).
) through the nozzle under pressure at 3~18 m/s.
Width 0.5 discharged and filled with gas and steam at a rate of
10-40% more than the fiber (3) at the exit position of the nozzle across a space of ~10 mm and subsequently under the nozzle.
By flowing the rapidly moving cooling liquid (1) at an angle of 45 to 90° with respect to the flow direction of the cooling liquid, an amorphous or metastable crystalline structure of any length and 50 to 10
In the method for producing metal fibers with a circular cross section and a diameter of 00 μm, the cooling liquid (1) in a short cooling section below the nozzle (4) and in the flow direction is inside a stationary channel (9). A method for producing round metal fibers with a circular cross section, characterized in that a laminar flow is formed and a drag reducing agent is added to the cooling liquid (1). 2. The method according to claim 1, wherein sodium salicylate and tetradecyltrimethylammonium bromide are added as resistance lowering agents. 3. Process according to claim 1, characterized in that the laminar flow under the nozzle (4) and inside the cooling section is caused to flow approximately horizontally or at a slight incline and in a straight line. 4. Apparatus for implementing the method according to any one of claims 1 to 3, comprising a melt container (2) subjected to gas pressure.
The bottom of the container is provided with one or more nozzles (4), and below the nozzles a section of the liquid circulation path (4) is provided.
9) is guided, the sections being separated from the outlet of the nozzle by a space of 0.5 to 10 mm filled with gas or steam, and one or more reels (14) directing the movement of the cooling liquid from the nozzle. In the type spaced apart in the direction, below each nozzle (4) there is provided a passageway (9) which is open at the top and extends straight horizontally or slightly inclined; An apparatus for producing metal fibers with a circular cross section, characterized by: 5. Device according to claim 4, characterized in that the reel (14) is installed at the end of the cooling section in such a way that it can be washed by the cooling liquid. 6. The apparatus of claim 4 or 5, wherein the melt crucible incorporates a plurality of nozzles and one passage and reel per nozzle. 7. Device according to any one of claims 4 to 6, characterized in that the coolant (1) consists of water and contains a drag reducing agent.