FI101457B - Methods of making a bimetallic material - Google Patents

Description

1 101457

WAY TO MANUFACTURE BIMETAL MATERIAL

The present invention is directed to a method of making a bimetallic material continuously so that the work steps in making the material can be substantially reduced.

5

Bimetallic material in this context means a metal preparation formed by two metal components, in which the components are either metals per se or alloys. Such bimetallic materials include, for example, a metal preparation formed of copper and niobititanium filaments incorporated therein as a superconductor.

A superconductor rich in copper and low in niobititanium can be manufactured, for example, as a channel conductor in which niobititanium acting as a superconductor is soldered into the groove of a copper profile. If it is desired to insulate such a duct 15, the insulation is generally performed by an enamelling process. In enamelling, the processing temperature of the duct conductor rises above the soldering temperature, whereupon the solder joint opens and the conductor is destroyed.

Copper- and low-niobititanium-rich superconductors can also be fabricated as a monolithic conductor, in which niobititanium is first packaged inside copper and the finished superconductor is the result of a fabrication process involving multiple modifications and heat treatment. In terms of the end result, multi-stage fabrication is only necessary for niobititanium, so that copper is part of the conductor and travels with it in all stages.

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In terms of manufacturing cost and unit length, a monolithic conductor is inferior to a duct conductor, but a monolithic conductor can be insulated in the enamelling process without damaging the conductor.

30 Continuous extrusion often uses a method described in GB Patent 1370894, called the Conform method. In this method, the material to be extruded 101457 is introduced into a groove formed on the outer circumference of the wheeled member. As the member rotates about its axis, the material to be extruded comes into contact with the counterpart substantially filling the groove, whereby the movement of the material to be dropped relative to the wheeled member changes. The material is thus caused to be dropped in the direction of travel of the material before the stop or through a drop hole placed in the stop. With the Conform method, it is possible to drop substantially long pieces with different cross-sections, preferably.

It is an object of the present invention to obviate the disadvantages of the prior art and to provide a better and more cost-effective way to produce a bimetallic material by continuous drop. The essential features of the invention will become apparent from the appended claims.

The bimetallic material to be produced according to the invention is dropped by a continuous extrusion device, such as a Conform device, so that the material flows substantially laminarly throughout the shaping treatment. Further, the bimetallic material is removed from the continuous extruder in a substantially radial direction. Thus, for example, for a bimetallic material rich in copper and low in niobititanium, the length of the prior art duct conductor and the insulability of the monolithic conductor are advantageously obtained.

In order to feed the drop bimetallic material to the continuous extrusion device, a larger volume of bimetallic component is preferably formed into a grooved profile, in the groove of which a smaller volume of bimetallic component is placed. The extrudable bimetallic component thus obtained is fed to the feed. to a rotary and preferably circumferentially grooved feed member of the continuous extruder.

When the bimetallic material to be dropped is, for example, a superconducting material rich in copper and 30 low in niobititanium, mixing of the different bimetallic components must be prevented. Based on this, the bimetallic blank from the feed member of the continuous drop device is directed to the extrusion so that the bimetallic material flows substantially laminarly throughout the extrusion. In addition, since the components of the bimetallic material are already in contact with each other in the feeding stage, the extruded bimetallic material can be removed from the extruding device 5 in a substantially radial direction with respect to the wheeled feeding device of the extruding device.

According to the invention, the counter-member substantially filling the groove of the feed member of the continuous extrusion device and the extrusion member including the extrusion opening are preferably shaped so as to provide a substantially laminar flow of the material to be dropped throughout the extrusion. To provide laminar flow, the channel leading to the extrusion opening in the extrusion member is shaped at least in the feed direction of the material to be dropped from its first wall so that the radius of curvature of the channel end is at least 70%, preferably 80-90% of the largest diameter of the extrusion opening . Further, the mating member substantially filling the groove of the feed member of the extrusion device is shaped such that the mating member forms a substantially concentric circular arc of the channel leading to the extrusion opening in the material feeding direction 20 with the first wall. The counterpart may also be shaped so that the material to be dropped itself forms a non-flowing region in front of the counterpart, which at the interface of the non-flowing and flowable area view.

Using the method according to the invention for the production of a bimetallic material, a bimetal component with a smaller volume can be centrally placed as the desired core material surrounded by a sheath formed by a material with a larger volume. According to the invention, such production of the bimetallic material 4 101457 preferably takes place in a single step and continuously, the extrusion ratio being such that the extrusion temperature is at least 600 ° C.

The invention will be described in more detail below with reference to the accompanying drawing, the figure of which shows a preferred embodiment of the invention.

According to the figure, the various components 1 and 2 of the desired bimetallic material are fed to the feed device 4 of the continuous extrusion device 3. The component 1 is formed into a grooved profile into the groove of which the component 2 is guided. The feeder 4 is substantially circular and the components 1 and 2 together are fed into a groove in the outer circumference of the feeder 4. The feeder 4 conveys the bimetal blank 5 containing components 1 and 2 to the extrusion zone. In the extrusion zone, the counterpart 6 filling the groove of the feeder 4 guides the extrusion hole 7 of the bimetal preform. Likewise, for the bimetallic material advancing laminarly in front of the counterpart 6, a flow-free region 10 is formed of at least a portion of the material to be dropped, the interface 11 with the flowing material forming a substantially concentric circular wall 20 with the wall 9 . The interface 11 preferably extends from the outer circumferential groove of the feeder 4 to the wall 12 of the extrusion member. The extruded finished bimetallic material discharges from the continuous extrusion device 3 substantially radially to the wheel of the feeder 4.

Claims (6)

A method of producing a bimetallic material with a continuously operating extruder (3), in which bimetallic components (1,2) are added to an extrusion zone, characterized in that the bimetallic material (1,2) to be extruded is caused to flow substantially laminarly. during the extrusion, and the bimetal material (1,2) is caused to flow out of the extruder (3) in a substantially radial direction relative to the outer periphery of the extruder's feeding means (4). 10 2. A method according to claim 1, characterized in that in order to provide a substantially laminar flow as abutment surface (11) for a stop member (6), a circular pitch which is substantially concentric with the first wall (9) of the extruder means is preferably provided. a distance corresponding to at most a 40 degree center angle (a) exiting from the point of change of flow in the supply direction of the components (1,2). 3. A method according to claim 1, characterized in that the abutment surface of the abutment member (6) is provided at least by a portion of the material to be extruded. 20 4. A method according to any of the preceding claims, characterized in that the first wall (9) of the extruder (8) has been rounded in the feed direction so that the radius of radius of the wall (9) is at least 70%, preferably 80-90% of the extruder opening (7). largest diameter. 25 5. A method according to any of the preceding claims, characterized in that the extrusion is carried out in one step. 6. A method according to claim 5, characterized in that the extrusion temperature rises at least to 600 ° C.