EP1242641B1 - Method for producing an aluminum-titanium-boron prealloy for use as a grain refiner - Google Patents
Method for producing an aluminum-titanium-boron prealloy for use as a grain refiner Download PDFInfo
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- EP1242641B1 EP1242641B1 EP00983193A EP00983193A EP1242641B1 EP 1242641 B1 EP1242641 B1 EP 1242641B1 EP 00983193 A EP00983193 A EP 00983193A EP 00983193 A EP00983193 A EP 00983193A EP 1242641 B1 EP1242641 B1 EP 1242641B1
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- prealloy
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/02—Making non-ferrous alloys by melting
- C22C1/026—Alloys based on aluminium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/02—Making non-ferrous alloys by melting
- C22C1/03—Making non-ferrous alloys by melting using master alloys
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- the invention relates to a method for producing a grain refining agent according to the preamble of claim 1.
- EP-A-0396389 describes a process for the continuous production of a Al-Ti-B grain refining alloy discloses, in which Ti and B-containing starting materials added to a molten aluminum reaction zone are, the melt being stirred in the reaction zone. A mixture the alloy formed becomes continuous together with the reaction products fed to a cleaning zone in which the slag with reaction products is collected on the surface of the melt and removed. The grain refining alloy formed is continuously removed from the cleaning station led to a casting station, in which the melt continuously is cast in one strand.
- the cast strand can either directly have the desired strand or wire thickness, or it can be further Processing by rolling or extrusion to the desired grain refining material are processed.
- the TiB 2 particles in the Al-Ti-B grain refining agents known today have a strong tendency to form agglomerates. This results in a reduced effect of the grain refining agent. Further disadvantages result from agglomerates and inclusions, which can lead to errors in the end product. Examples include gray lines, holes, material separations and stringers.
- agglomerates occur preferentially on low-melting salts such as KF and NaCl as well as on oxide skins and can thereby further increase. As such, the agglomerates are "soft", can force themselves through filters and as such end up in a cast strand.
- the invention is therefore based on the object of providing a process for producing an Al-Ti-B grain refining agent with which the formation of agglomerates of TiB 2 particles can be largely prevented and existing agglomerates can be deagglomerated.
- cavitation ie the formation of bubbles
- the implosion of which generates shock waves leads to the deagglomeration of agglomerated TiB 2 particles.
- the latter methods include, for example, ultrasound treatment and vibration using a magnetostrictive resonator.
- the grain refining agent produced by the process according to the invention brings about an improved and more homogeneous effect of the refining agent, particularly in the case of grain refinement of casting formats made of aluminum alloys, by a more homogeneous distribution of the individual TiB 2 particles, a better coating of the TiB 2 particles with Al 3 Ti phase and one Reduction or dispersion of any salts and oxide inclusions still present in the grain refining agent.
- the master alloy is preferably set in motion before the liquidus temperature of the Al 3 Ti phase is undershot.
- the effect of the grain refining agent produced according to the invention is shown by the fact that the individual, approximately 0.5 to 5 ⁇ m large TiB 2 particles have an excellent germination effect as a result of a coating formed from a thin Al 3 Ti layer and the particles are isolated and not as agglomerates act so that a comparable grain refinement can be achieved with a considerably smaller amount of grain refining agent than with grain refining agents according to the prior art.
- the liquidus temperature of the Al 3 Ti phase is dropped below prematurely. This is especially the case when a master alloy with a high Ti content and a correspondingly higher liquidus temperature is produced or when a master alloy that has already solidified is assumed.
- By heating the melt again above the liquidus temperature already precipitated Al 3 Ti particles can be completely dissolved again. This process typically takes 5 to 60 minutes, depending on the size of the Al 3 Ti particles.
- the Ultrasonic movement of the melt with a frequency of 10 to 50 kHz generated.
- the second cooling rate is preferably greater than 2 ° C./sec, in particular greater than 5 ° C / sec.
- the master alloy melt can be cast into any format. However, preference is given to casting by vertical or horizontal continuous casting continuously produced strand. This strand can either already in the format of the rod or Cast wire material or in a further operation by rolling or presses to be processed into bar or wire material. Vertically cast, large-sized strands are mainly processed by extrusion. Horizontal continuous casting of formats is preferred relatively small diameter because this process is continuous Manufacturing allowed. The horizontally cast continuous casting formats are preferably by rolling to the desired bar or wire material processed.
- a master alloy produced using the method according to the invention has a composition whose total titanium content exceeds the stoichiometric ratio of TiB 2 .
- a preferred alloy used contains titanium and boron in a weight ratio of 5: 2 to 10: 1.
- the process is suitable for producing master alloys with 0.15 to 20% by weight of titanium and 0.01 to 4% by weight of boron, it has proven to be advantageous if the master alloy contains 0.3 to 5, preferably 0.5 to 2,% by weight. % Ti and 0.02 to 1, preferably 0.05 to 0.5 wt .-% B contains.
- the method according to the invention is particularly suitable for production of grain refining agents for the grain refining of aluminum and aluminum alloys.
- FIG. 1 This is schematic in the Al-Ti equilibrium diagram shown in FIG. 1 Process flow shown for the production of an Al-Ti-B master alloy drawn in for grain refinement of aluminum alloys.
- the illustration A of the alloy phases to the left of the 0.5% Ti line shows the processes during the preparation of an already solidified master alloy, the illustration B to the right of the 0.5% Ti line shows the processes during the solidification of the master alloy.
- the master alloy melt contains TiB 2 particles in partially agglomerated form. Even before the liquidus temperature T L Al3Ti is undershot and shortly before the solidus temperature T s v of the pre-alloy of the Al 3 Ti phase is reached, the partially agglomerated TiB 2 particles are deagglomerated by a strong melt movement using ultrasound treatment at a frequency of, for example, 25 kHz and distributed homogeneously. Simultaneous controlled cooling with a first cooling rate v 1 of, for example, 0.5 ° C./sec, causes the deposition of a thin layer of the Al 3 Ti phase on the parallel surfaces of the TiB 2 particles and at the same time the formation of coarse-grained Al 3 Ti particles prevented.
- a first cooling rate v 1 of, for example, 0.5 ° C./sec
- a system 10 shown in FIG. 2 for producing an Al-Ti-B master alloy for grain refining of aluminum alloys comprises a reaction vessel 12 with an inlet channel 14 in its upper region and an outlet channel 16 in its lower region.
- the reaction vessel 12 is surrounded by an induction motor 18 as an electromagnetic stirring device, with which the aluminum melt 20 located in the reaction vessel 12 is stirred vigorously to form a vortex 22.
- Salts containing Ti and B, such as K 2 TiF 6 and KBF 4 are guided in the direction of arrow 24 into the vortex 22, which draws the salts into the aluminum melt 20.
- the aluminum melt 20 with the reaction products is shown below through the outlet duct 16 via a further inlet duct 26 into the upper one Area of an aftertreatment boiler 28 out.
- Another electromagnetic Stirring device 30 in the lower area of the aftertreatment boiler 28 leads to a lower turbulent zone 32 and an upper calm Zone 34.
- the slag 36 formed by reaction products is over the removal opening 38 is removed from the aftertreatment boiler 28.
- the cleaned aluminum melt 20 with the elements titanium and boron contained therein is fed as a pre-alloy in the lower region of the aftertreatment boiler 28 via a casting trough 38 to a mold, not shown in the drawing, of a horizontal continuous casting machine.
- Two ultrasonic transmitters 40, 42 are arranged in the region of the casting trough 38, the sonotrodes 44, 46 of which immerse in the melt.
- An induction heater 48 arranged below the casting trough 38 serves to heat the melt if its temperature should have already dropped below the liquidus temperature T L Al3Ti of the Al 3 Ti phase when the melt flows from the aftertreatment boiler 28 into the casting trough 38.
Abstract
Description
Die Erfindung betrifft ein Verfahren zur Herstellung eines Kornfeinungsmittels nach dem Oberbegriff von Anspruch 1.The invention relates to a method for producing a grain refining agent according to the preamble of claim 1.
In der EP-A-0396389 ist ein Verfahren zur kontinuierlichen Herstellung einer Al-Ti-B-Kornfeinungslegierung offenbart, bei welchem Ti- und B-haltige Ausgangsmaterialien in einer Reaktionszone einer Aluminiumschmelze zugegeben werden, wobei die Schmelze in der Reaktionszone gerührt wird. Eine Mischung der gebildeten Legierung wird zusammen mit den Reaktionsprodukten kontinuierlich einer Reinigungszone zugeführt, in welcher die Schlacke mit Reaktionsprodukten an der Oberfläche der Schmelze gesammelt und abgeführt wird. Die gebildete Kornfeinungslegierung wird kontinuierlich von der Reinigungsstation zu einer Giessstation geführt, in welcher die Schmelze kontinuierlich zu einem Strang vergossen wird. Der gegossene Strang kann entweder direkt die gewünschte Strang- oder Drahtdicke aufweisen, oder er kann durch weitere Bearbeitung durch Walzen oder Strangpressen zum gewünschten Kornfeinungsmaterial verarbeitet werden.EP-A-0396389 describes a process for the continuous production of a Al-Ti-B grain refining alloy discloses, in which Ti and B-containing starting materials added to a molten aluminum reaction zone are, the melt being stirred in the reaction zone. A mixture the alloy formed becomes continuous together with the reaction products fed to a cleaning zone in which the slag with reaction products is collected on the surface of the melt and removed. The grain refining alloy formed is continuously removed from the cleaning station led to a casting station, in which the melt continuously is cast in one strand. The cast strand can either directly have the desired strand or wire thickness, or it can be further Processing by rolling or extrusion to the desired grain refining material are processed.
In dem Artikel von P. Schumacher et al, New studies of nucleation mechanisms in aluminium alloys: implications for grain refinement practice, Materials Science and Technology, May 1998, Vol. 14, Seiten 394 bis 404, ist eine plausible Theorie zum Ablauf der Vorgänge bei der Kornfeinung von Aluminiumlegierungen durch Zugabe einer Al-Ti-B-Vorlegierung der beispielsweisen Zusammensetzung AlTi5B1 bekannt. Nach dieser Theorie ergeben sich die besten Kornfeinungsergebnisse dann, wenn die in der Aluminiumschmelze unlöslichen TiB2-Partikel an deren Oberfläche zumindest teilweise mit einer Schicht aus Al3Ti-Phase belegt sind. Die Keimbildung der α-Aluminium-Phase erfolgt an den Al3Ti-Schichten, deren Wirkung mit abnehmender Schichtdicke zunimmt.In the article by P. Schumacher et al, New studies of nucleation mechanisms in aluminum alloys: implications for grain refinement practice, Materials Science and Technology, May 1998, Vol. 14, pages 394 to 404, there is a plausible theory on the sequence of events known in the grain refinement of aluminum alloys by adding an Al-Ti-B pre-alloy of the exemplary composition AlTi5B1. According to this theory, the best grain refinement results are obtained if the surface of the TiB 2 particles that are insoluble in the aluminum melt is at least partially covered with a layer of Al 3 Ti phase. The α-aluminum phase is nucleated on the Al 3 Ti layers, the effect of which increases with decreasing layer thickness.
Ein Verfahren der eingangs genannten Art ist aus der US-A-3 785 807 bekannt.A method of the type mentioned at the outset is known from US Pat. No. 3,785,807 known.
Die TiB2-Partikel in den heute bekannten Al-Ti-B-Kornfeinungsmitteln neigen stark zur Bildung Agglomeraten. Dadurch ergibt sich eine verminderte Wirkung des Kornfeinungsmittels. Weitere Nachteile ergeben sich durch Agglomerate und Einschlüsse, die zu Fehlern im Endprodukt führen können. Beispiele hierfür sind Grauzeilen, Löcher, Materialtrennungen und Stringers. Zudem treten Agglomerate bevorzugt an niedrig schmelzenden Salzen wie beispielsweise KF und NaCl sowie an Oxidhäuten auf und können sich dadurch weiter vergrössem. Die Agglomerate sind als solche "weich", können sich durch Filter zwängen und gelangen als solche in einen gegossenen Strang.The TiB 2 particles in the Al-Ti-B grain refining agents known today have a strong tendency to form agglomerates. This results in a reduced effect of the grain refining agent. Further disadvantages result from agglomerates and inclusions, which can lead to errors in the end product. Examples include gray lines, holes, material separations and stringers. In addition, agglomerates occur preferentially on low-melting salts such as KF and NaCl as well as on oxide skins and can thereby further increase. As such, the agglomerates are "soft", can force themselves through filters and as such end up in a cast strand.
Der Erfindung liegt deshalb die Aufgabe zugrunde, ein Verfahren zur Herstellung eines Al-Ti-B-Kornfeinungsmittels bereitzustellen, mit welchem die Bildung von Agglomeraten von TiB2-Partikeln weitgehend unterbunden werden kann und bereits vorhandene Agglomerate deagglomeriert werden können.The invention is therefore based on the object of providing a process for producing an Al-Ti-B grain refining agent with which the formation of agglomerates of TiB 2 particles can be largely prevented and existing agglomerates can be deagglomerated.
Die Aufgabe wird gelöst durch die Merkmale von Anspruch 1. The object is achieved by the features of claim 1.
Die Erzeugung von Kavitation, d.h. die Bildung von Blasen, deren Implosion Schockwellen erzeugt führt zur Deagglomerierung agglomerierter TiB2 Partikel. Zu den letztgenannten Verfahren gehören beispielsweise die Ultraschallbehandlung sowie die Vibration mittels eines magnetostriktiven Resonators.The generation of cavitation, ie the formation of bubbles, the implosion of which generates shock waves leads to the deagglomeration of agglomerated TiB 2 particles. The latter methods include, for example, ultrasound treatment and vibration using a magnetostrictive resonator.
Das mit dem erfindungsgemässen Verfahren hergestellte Kornfeinungsmittel bewirkt insbesondere bei der Kornfeinung von Gussformaten aus Aluminiumlegierungen eine verbesserte und homogenere Wirkung des Komfeinungsmittels durch eine homogenere Verteilung der einzelnen TiB2-Partikel, eine bessere Beschichtung der TiB2-Partikel mit Al3Ti-Phase sowie eine Verminderung oder Dispergierung allenfalls noch vorhandener Salze und Oxideinschlüsse im Kornfeinungsmittel.The grain refining agent produced by the process according to the invention brings about an improved and more homogeneous effect of the refining agent, particularly in the case of grain refinement of casting formats made of aluminum alloys, by a more homogeneous distribution of the individual TiB 2 particles, a better coating of the TiB 2 particles with Al 3 Ti phase and one Reduction or dispersion of any salts and oxide inclusions still present in the grain refining agent.
Bevorzugt wird die Vorlegierung bereits vor dem Unterschreiten der Liquidustemperatur der Al3Ti-Phase in Bewegung versetzt.The master alloy is preferably set in motion before the liquidus temperature of the Al 3 Ti phase is undershot.
Die Wirkung des erfindungsgemäss hergestellten Kornfeinungsmittels zeigt sich dadurch, dass die vereinzelten, etwa 0.5 bis 5 µm grossen TiB2-Partikel als Folge eines sich bildenden Überzuges aus einer dünnen Al3Ti-Schicht eine ausgezeichnete Keimwirkung zeigen und die Partikel vereinzelt und nicht als Agglomerate wirken, so dass eine vergleichbare Kornfeinung mit einer erheblich kleineren Menge an Kornfeinungsmittel erzielt werden kann als mit Kornfeinungsmitteln nach dem Stand der Technik. In der Praxis bedeutet dies, dass die Kornfeinungsmittel in wesentlich verdünnterer Form hergestellt werden können, was die Neigung der TiB2-Partikel zur Agglomeratbildung zusätzlich weiter vermindert.The effect of the grain refining agent produced according to the invention is shown by the fact that the individual, approximately 0.5 to 5 μm large TiB 2 particles have an excellent germination effect as a result of a coating formed from a thin Al 3 Ti layer and the particles are isolated and not as agglomerates act so that a comparable grain refinement can be achieved with a considerably smaller amount of grain refining agent than with grain refining agents according to the prior art. In practice, this means that the grain refining agents can be produced in a much more dilute form, which further reduces the tendency of the TiB 2 particles to form agglomerates.
Je nach Konstellation der zur Durchführung des erfindungsgemässen Verfahrens eingesetzten Vorrichtung kann es vorkommen, dass die Liquidustemperatur der Al3Ti-Phase vorzeitig unterschritten wird. Dies ist vor allem dann der Fall, wenn eine Vorlegierung mit einem hohen Ti-Gehalt und entsprechend erhöhter Liquidustemperatur hergestellt oder wenn von einer bereits erstarrten Vorlegierung ausgegangen wird. Durch erneutes Aufheizen der Schmelze über die Liquidustemperatur können bereits ausgeschiedene Al3Ti-Partikel wieder vollständig in Lösung gebracht werden. Dieser Vorgang benötigt typischerweise 5 bis 60 min, je nach Grösse der Al3Ti-Partikel.Depending on the constellation of the device used to carry out the method according to the invention, it may happen that the liquidus temperature of the Al 3 Ti phase is dropped below prematurely. This is especially the case when a master alloy with a high Ti content and a correspondingly higher liquidus temperature is produced or when a master alloy that has already solidified is assumed. By heating the melt again above the liquidus temperature, already precipitated Al 3 Ti particles can be completely dissolved again. This process typically takes 5 to 60 minutes, depending on the size of the Al 3 Ti particles.
Bei einem bevorzugten erfindungsgemässen Verfahren wird die Bewegung der Schmelze mittels Ultraschall mit einer Frequenz von 10 bis 50 kHz erzeugt.In a preferred method according to the invention, the Ultrasonic movement of the melt with a frequency of 10 to 50 kHz generated.
Die zweite Abkühlungsgeschwindigkeit ist bevorzugt grösser als 2°C/sec, insbesondere grösser als 5°C/sec.The second cooling rate is preferably greater than 2 ° C./sec, in particular greater than 5 ° C / sec.
Die Vorlegierungsschmelze kann zu irgendeinem Format vergossen werden. Bevorzugt wird jedoch ein zweckmässigerweise durch Vertikal- oder Horizontalstranggiessen kontinuierlich hergestellter Strang. Dieser Strang kann entweder bereits im Format des als Kornfeinungsmittel gewünschten Stangen- oder Drahtmaterials gegossen oder in einem weiteren Arbeitsgang durch Walzen oder Pressen zu Stangen- oder Drahtmaterial verarbeitet werden. Vertikal gegossene, grossformatige Stränge werden vor allem durch Strangpressen weiterverarbeitet. Bevorzugt wird das Horizontalstranggiessen von Formaten mit verhältnismässig kleinem Durchmesser, da dieses Verfahren eine kontinuierliche Herstellung erlaubt. Die horizontal gegossenen Stranggiessformate werden bevorzugt durch Walzen zum gewünschten Stangen- oder Drahtmaterial verarbeitet.The master alloy melt can be cast into any format. However, preference is given to casting by vertical or horizontal continuous casting continuously produced strand. This strand can either already in the format of the rod or Cast wire material or in a further operation by rolling or presses to be processed into bar or wire material. Vertically cast, large-sized strands are mainly processed by extrusion. Horizontal continuous casting of formats is preferred relatively small diameter because this process is continuous Manufacturing allowed. The horizontally cast continuous casting formats are preferably by rolling to the desired bar or wire material processed.
Eine mit dem erfindungsgemässen Verfahren hergestellte Vorlegierung weist eine Zusammensetzung auf, deren Gesamtgehalt an Titan das stöchimetrische Verhältnis von TiB2 übersteigt. Eine bevorzugt eingesetzte Vorlegierung enthält Titan und Bor im Gewichtsverhältnis 5:2 bis 10:1. Obschon sich das Verfahren zur Herstellung von Vorlegierungen mit 0.15 bis zu 20 Gew.-% Titan und 0.01 bis 4 Gew.-% Bor eignet, hat es sich als günstig erwiesen, wenn die Vorlegierung 0.3 bis 5, vorzugsweise 0.5 bis 2 Gew.-% Ti und 0.02 bis 1, vorzugsweise 0.05 bis 0.5 Gew.-% B enthält.A master alloy produced using the method according to the invention has a composition whose total titanium content exceeds the stoichiometric ratio of TiB 2 . A preferred alloy used contains titanium and boron in a weight ratio of 5: 2 to 10: 1. Although the process is suitable for producing master alloys with 0.15 to 20% by weight of titanium and 0.01 to 4% by weight of boron, it has proven to be advantageous if the master alloy contains 0.3 to 5, preferably 0.5 to 2,% by weight. % Ti and 0.02 to 1, preferably 0.05 to 0.5 wt .-% B contains.
Das erfindungsgemässe Verfahren eignet sich insbesondere zur Herstellung von Kornfeinungsmitteln für die Kornfeinung von Aluminium und Aluminiumlegierungen.The method according to the invention is particularly suitable for production of grain refining agents for the grain refining of aluminum and aluminum alloys.
Weitere Vorteile, Merkmale und Einzelheiten der Erfindung ergeben sich aus der nachfolgenden Beschreibung bevorzugter Ausführungsbeispiele sowie anhand der Zeichnung; diese zeigt schematisch in
- Fig. 1 einen Ausschnitt aus dem Al-Ti-Gleichgewichtsdiagramm;
- Fig. 2 einen Querschnitt durch eine Anlage zur Herstellung einer Al-Ti-B-Vorlegierung.
- 1 shows a section of the Al-Ti equilibrium diagram;
- Fig. 2 shows a cross section through a plant for producing an Al-Ti-B master alloy.
In dem in Fig. 1 dargestellten Al-Ti-Gleichgewichtsdiagramm ist der schematisch dargestellte Verfahrensablauf zur Herstellung einer Al-Ti-B-Vorlegierung zur Kornfeinung von Aluminiumlegierungen eingezeichnet.This is schematic in the Al-Ti equilibrium diagram shown in FIG. 1 Process flow shown for the production of an Al-Ti-B master alloy drawn in for grain refinement of aluminum alloys.
Eine nach dem erfindungsgemässen Verfahren hergestellte Vorlegierung mit einer Zusammensetzung entsprechend AlTi0.7B0.1, die etwa 0.5% nicht an Bor gebundenes Titan enthält, weist eine Ausgangstemperatur von etwa 840°C auf und liegt somit über der für diese Legierungszusammensetzung etwa bei 800°C liegenden Liquidustemperatur TL Al3Ti der Al3Ti-Phase. Die bildliche Darstellung A der Legierungsphasen links von der 0.5% Ti-Linie zeigt die Vorgänge bei der Aufbereitung einer bereits erstarrten Vorlegierung, die Darstellung B rechts von der 0.5%Ti-Linie die Vorgänge während der Erstarrung der Vorlegierung.A master alloy produced by the process according to the invention with a composition corresponding to AlTi0.7B0.1, which contains about 0.5% titanium not bound to boron, has an initial temperature of about 840 ° C. and is therefore above that for this alloy composition at about 800 ° C. lying liquidus temperature T L Al3Ti of the Al 3 Ti phase. The illustration A of the alloy phases to the left of the 0.5% Ti line shows the processes during the preparation of an already solidified master alloy, the illustration B to the right of the 0.5% Ti line shows the processes during the solidification of the master alloy.
Die Vorlegierungsschmelze enthält TiB2-Partikel in teilweise agglomerierter Form. Bereits vor dem Unterschreiten der Liquidustemperatur TL Al3Ti und bis kurz vor dem Unterschreiten der Solidustemperatur Ts v der Vorlegierung der Al3Ti-Phase werden die teilweise agglomerierten TiB2-Partikel durch eine starke Schmelzebewegung mittels Ultraschallbehandlung bei einer Frequenz von beispielsweise 25 kHz deagglomeriert und homogen verteilt. Durch gleichzeitiges kontrolliertes Abkühlen mit einer ersten Abkühlgeschwindigkeit v1 von z.B. 0.5°C/sec wird die Abscheidung einer dünnen Schicht der Al3Ti-Phase auf den parallelen Oberflächen der TiB2-Partikel bewirkt und gleichzeitig die Bildung von grobkörnigen Al3Ti-Partikeln verhindert. Bei der nachfolgenden starken Abkühlung mit einer gegenüber der ersten Abkühlungsgeschwindigkeit v1 höheren zweiten Abkühlungsgeschwindigkeit v2 von beispielsweise 10°C/sec unter die Solidustemperatur TS V der Vorlegierung wird sichergestellt, dass sich die Al3Ti-Schicht auf den TiB2-Partikeln nicht vollständig auflöst und auch keine weitere Bildung bzw. Vergröberung von Al3Ti-Partikeln eintritt.The master alloy melt contains TiB 2 particles in partially agglomerated form. Even before the liquidus temperature T L Al3Ti is undershot and shortly before the solidus temperature T s v of the pre-alloy of the Al 3 Ti phase is reached, the partially agglomerated TiB 2 particles are deagglomerated by a strong melt movement using ultrasound treatment at a frequency of, for example, 25 kHz and distributed homogeneously. Simultaneous controlled cooling with a first cooling rate v 1 of, for example, 0.5 ° C./sec, causes the deposition of a thin layer of the Al 3 Ti phase on the parallel surfaces of the TiB 2 particles and at the same time the formation of coarse-grained Al 3 Ti particles prevented. During the subsequent strong cooling with a second cooling speed v 2 higher than the first cooling speed v 1 of, for example, 10 ° C./sec below the solidus temperature T S V of the master alloy, it is ensured that the Al 3 Ti layer is on the TiB 2 particles does not dissolve completely and no further formation or coarsening of Al 3 Ti particles occurs.
Eine in Fig. 2 gezeigte Anlage 10 zur Herstellung einer Al-Ti-B-Vorlegierung
zum Kornfeinen von Aluminiumlegierungen umfasst einen Reaktionskessel 12
mit einem Einlasskanal 14 in dessen oberem Bereich und einem Auslasskanal
16 in dessen unterem Bereich. Der Reaktionskessel 12 ist umgeben von einem
Induktionsmotor 18 als elektromagnetische Rühreinrichtung, mit der die sich im
Reaktionskessel 12 befindende Aluminiumschmelze 20 unter Bildung eines
Vortex 22 stark gerührt wird. Ti- und B-haltige Salze wie z.B. K2TiF6 und KBF4
werden in Pfeilrichtung 24 in den Vortex 22 geführt, welcher die Salze in die
Aluminiumschmelze 20 hineinzieht.A
Die Aluminiumschmelze 20 mit den Reaktionsprodukten wird nachfolgend
durch den Auslasskanal 16 über einen weiteren Einlasskanal 26 in den oberen
Bereich eines Nachbehandlungskessels 28 geführt. Eine weitere elektromagnetische
Rühreinrichtung 30 im unteren Bereich des Nachbehandlungskessels
28 führt zu einer unteren turbulenten Zone 32 und einer oberen beruhigten
Zone 34. Die durch Reaktionsprodukte gebildete Schlacke 36 wird über
die Entnahmeöffnung 38 aus dem Nachbehandlungskessel 28 entfernt.The
Die gereinigte Aluminiumschmelze 20 mit den darin enthaltenen Elementen
Titan und Bor wird als Vorlegierung im unteren Bereich des Nachbehandlungskessels
28 über eine Giessrinne 38 einer in der Zeichnung nicht gezeigten Kokille
einer Horizontalstranggiessmaschine zugeführt. Im Bereich der Giessrinne
38 sind zwei Ultraschallgeber 40, 42 angeordnete, deren Sonotroden 44, 46 in
die Schmelze eintauchen. Eine Unterhalb der Giessrinne 38 angeordnete Induktionsheizung
48 dient zum Aufheizen der Schmelze, falls deren Temperatur
beim Einlauf der Schmelze vom Nachbehandlungskessel 28 in die Giessrinne
38 bereits unter die Liquidustemperatur TL Al3Ti der Al3Ti-Phase gefallen sein
sollte.The cleaned
Claims (12)
- Method of producing a grain refiner based on an aluminium-titanium-boron prealloy by introducing starting materials containing Ti and B into an aluminium melt with the formation of TiB2 particles, in which method the TiB2 particles act as nuclei for the Al3Ti phase occurring below the liquidus temperature (TL Al3Ti) of the Al3Ti phase and the surfaces of the TiB2 particles are at least partially covered in a coating of Al3Ti, and allowing this prealloy melt to solidify, characterised in that the prealloy is set in motion between the liquidus temperature (TL Al3Ti) of the Al3Ti phase and the solidus temperature (Ts v) of the prealloy in order to disperse the TiB2 particles in the melt in order to produce cavitation by vibration at a frequency of 50 Hz to 50 kHz, and is simultaneously cooled to below the solidus temperature (Ts v) of the prealloy at a first cooling rate (v1) and then at a second cooling rate (v2) which is higher than the first cooling rate (v1) at more than 1°C/sec.
- Method according to claim 1, characterised in that the prealloy is set in motion before the temperature falls below the liquidus temperature (TL Al3Ti) of the Al3Ti phase.
- Method according to claim 1 or claim 2, characterised in that, if the temperature falls prematurely below the liquidus temperature (TL Al3Ti) or if solidification has already taken place, the prealloy is heated to above the liquidus temperature (TL Al3Ti) until Al3Ti particles already precipitated out in the melt are fully dissolved.
- Method according to one of claims 1 to 3, characterised in that the movement of the melt is produced by means of a magnetostrictive resonator or by means of ultrasound.
- Method according to one of claims 1 to 4, characterised in that the second cooling rate (v2) is greater than 2°C/sec, in particular greater than 5°C/sec.
- Method according to one of claims 1 to 5, characterised in that the prealloy melt is cast into a strand.
- Method according to claim 6, characterised in that a continuous strand is produced, preferably by horizontal continuous casting.
- Method according to claim 6 or claim 7, characterised in that the strand is redrawn into grain-refining rods or wire.
- Method according to one of claims 1 to 8, characterised in that the prealloy has a composition such that the total titanium content exceeds the stoichiometric ratio of TiB2.
- Method according to one of claims 1 to 9, characterised in that the prealloy contains Ti and B in a weight ratio of 5:2 to 10:1.
- Method according to one of claims 1 to 10, characterised in that the prealloy contains 0.05 to 20, preferably 0.1 to 5, in particular 0.5 to 2 % by weight Ti and 0.01 to 4, preferably 0.02 to 1, in particular 0.05 to 0.5 % by weight B.
- Method according to one of claims 1 to 11, characterised in that grain refiners for the grain refinement of aluminium and aluminium alloys are produced from the prealloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP00983193A EP1242641B1 (en) | 1999-12-10 | 2000-11-30 | Method for producing an aluminum-titanium-boron prealloy for use as a grain refiner |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP99811137 | 1999-12-10 | ||
| EP99811137A EP1114875A1 (en) | 1999-12-10 | 1999-12-10 | Method of producing an aluminium-titanium-boron motheralloy for use as a grain refiner |
| PCT/EP2000/012015 WO2001042521A1 (en) | 1999-12-10 | 2000-11-30 | Method for producing an aluminum-titanium-boron prealloy for use as a grain refiner |
| EP00983193A EP1242641B1 (en) | 1999-12-10 | 2000-11-30 | Method for producing an aluminum-titanium-boron prealloy for use as a grain refiner |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP1242641A1 EP1242641A1 (en) | 2002-09-25 |
| EP1242641B1 true EP1242641B1 (en) | 2004-02-18 |
Family
ID=8243179
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP99811137A Withdrawn EP1114875A1 (en) | 1999-12-10 | 1999-12-10 | Method of producing an aluminium-titanium-boron motheralloy for use as a grain refiner |
| EP00983193A Expired - Lifetime EP1242641B1 (en) | 1999-12-10 | 2000-11-30 | Method for producing an aluminum-titanium-boron prealloy for use as a grain refiner |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP99811137A Withdrawn EP1114875A1 (en) | 1999-12-10 | 1999-12-10 | Method of producing an aluminium-titanium-boron motheralloy for use as a grain refiner |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US20030075020A1 (en) |
| EP (2) | EP1114875A1 (en) |
| CA (1) | CA2394485A1 (en) |
| DE (1) | DE50005366D1 (en) |
| WO (1) | WO2001042521A1 (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TR200504376A2 (en) * | 2005-11-02 | 2008-05-21 | T�B�Tak-T�Rk�Ye B�L�Msel Ve Tekn�K Ara�Tirma Kurumu | A process for producing grain-reducing pre-alloys |
| CN101768708B (en) * | 2010-02-05 | 2012-05-23 | 深圳市新星轻合金材料股份有限公司 | Method for controlling variable quantity of grain refining capacity of aluminum-titanium-boron alloy by controlling compression ratio |
| CN105671350A (en) * | 2015-03-19 | 2016-06-15 | 中信戴卡股份有限公司 | Aluminum alloy refiner, preparation method therefor and use thereof |
| EP3162460A1 (en) | 2015-11-02 | 2017-05-03 | Mubea Performance Wheels GmbH | Light metal casting part and method of its production |
| RU2625375C2 (en) * | 2015-12-03 | 2017-07-13 | Федеральное государственное бюджетное учреждение науки Институт металлургии Уральского отделения Российской академии наук (ИМЕТ УрО РАН) | Manufacture method of composite alloys and plant for its implementation |
| CN107377914A (en) * | 2017-08-04 | 2017-11-24 | 江西金世纪特种焊接材料有限公司 | A kind of Welded material melting continuous casting installation for casting |
| FR3082763A1 (en) | 2018-06-25 | 2019-12-27 | C-Tec Constellium Technology Center | PROCESS FOR MANUFACTURING AN ALUMINUM ALLOY PART |
| CN109371277A (en) * | 2018-12-11 | 2019-02-22 | 徐州宁铝业科技有限公司 | A kind of refining agent and preparation method for aluminium alloy smelting |
| CN110157935B (en) * | 2019-06-28 | 2021-05-07 | 上海大学 | Al-V-B refiner for casting aluminum-silicon alloy, preparation method and application thereof |
| CN110195168B (en) * | 2019-07-12 | 2021-01-01 | 东北大学 | Preparation process of aluminum-titanium-boron refiner plate |
| CN114959348B (en) * | 2022-06-09 | 2023-12-05 | 上海大学 | High-dispersity Al-xMB 2 Preparation method and application method of refiner |
| CN115558821B (en) * | 2022-12-06 | 2023-03-10 | 北京航空航天大学 | Realize TiB 2 Preparation method of size-controllable Al-Ti-B refiner |
| CN115976373A (en) * | 2022-12-30 | 2023-04-18 | 中山瑞泰铝业有限公司 | Processing technology and application of aluminum alloy material |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE349331B (en) * | 1970-04-28 | 1972-09-25 | Svenska Aluminiumkompaniet Ab | |
| US4612073A (en) * | 1984-08-02 | 1986-09-16 | Cabot Corporation | Aluminum grain refiner containing duplex crystals |
| US5230754A (en) * | 1991-03-04 | 1993-07-27 | Kb Alloys, Inc. | Aluminum master alloys containing strontium, boron, and silicon for grain refining and modifying aluminum alloys |
-
1999
- 1999-12-10 EP EP99811137A patent/EP1114875A1/en not_active Withdrawn
-
2000
- 2000-11-30 EP EP00983193A patent/EP1242641B1/en not_active Expired - Lifetime
- 2000-11-30 CA CA002394485A patent/CA2394485A1/en not_active Abandoned
- 2000-11-30 US US10/148,659 patent/US20030075020A1/en not_active Abandoned
- 2000-11-30 WO PCT/EP2000/012015 patent/WO2001042521A1/en active IP Right Grant
- 2000-11-30 DE DE50005366T patent/DE50005366D1/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| US20030075020A1 (en) | 2003-04-24 |
| DE50005366D1 (en) | 2004-03-25 |
| WO2001042521A8 (en) | 2001-07-12 |
| CA2394485A1 (en) | 2001-06-14 |
| EP1242641A1 (en) | 2002-09-25 |
| EP1114875A1 (en) | 2001-07-11 |
| WO2001042521A1 (en) | 2001-06-14 |
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