EP0263070B1 - Process for the production of a fine-grained recrystallised sheet - Google Patents
Process for the production of a fine-grained recrystallised sheet Download PDFInfo
- Publication number
- EP0263070B1 EP0263070B1 EP87810554A EP87810554A EP0263070B1 EP 0263070 B1 EP0263070 B1 EP 0263070B1 EP 87810554 A EP87810554 A EP 87810554A EP 87810554 A EP87810554 A EP 87810554A EP 0263070 B1 EP0263070 B1 EP 0263070B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- alloy
- sheet
- thickness
- state
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
- C22F1/057—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with copper as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
- C22F1/053—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with zinc as the next major constituent
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S420/00—Alloys or metallic compositions
- Y10S420/902—Superplastic
Definitions
- the invention relates to a method for producing a fine-grained recrystallized sheet suitable for superplastic forming from a hardenable aluminum alloy.
- the hardenable aluminum alloys are those in which an increase in strength can be brought about not only by cold forming but also by heat treatment. These include, in particular, alloys of the AIMgSi, AICuMg, AICuMgSi, AIZnMg, AIZnMgCu type and Li-containing variants thereof. These alloys have a tendency to form coarse grains if the solution annealing required for precipitation hardening is associated with recrystallization. For numerous applications, especially for superplastic forming, fine grain is desirable or a requirement. For sheet metal which is to be superplastically formed, a grain size of less than 25 wm, preferably less than 10 flm is required. The grains should also be almost globulitic. In addition, no significant coarsening of the grains may occur during the superplastic forming, which is carried out at about 500 ° C.
- the inventors have therefore set themselves the task of creating a process which, when applicable to all hardenable aluminum alloy types, leads to a fine-grained recrystallized sheet suitable for superplastic forming with high security and wide tolerance with regard to unspecified process parameters.
- the object is achieved in that the alloy used additionally contains at least one of the elements Ti, Zr, Hf, V Nb, Ta, Cr, Mo, W with a total weight fraction of 0.08 to 1.5% and that the alloy is in a state A is brought, in which both the alloying elements leading to hardening and the additional elements mentioned are at least largely in solid solution, whereupon in a step B the incoherent hardening phases in a temperature range between the separation zone solvus T gp s and the solvus of the equilibrium hardening phases T s are excreted and in a subsequent step C, the aluminides of the additional elements mentioned are uniformly excreted with high density by annealing in a temperature range between 300 ° C.
- any rolling deformations between state A and step C at temperatures of at most T s -30 ° C may continue that Le Government after the step C with at least 60% thickness reduction is so rolled into a sheet of thickness d, the temperature of the sheet from a thickness of 2.5xd 220 ° C does not exceed, and that the sheet with thickness d to a recrystallizing treatment D such is heated up that the heating rate is at least 20 ° C / s up to above the recrystallization threshold.
- the step B can be used as annealing in the temperature range between T s gp and T s are carried out, and in the form of a hot rolling operation at starting temperature below T s -30 ° C and end temperature above TGPS, or as a combination of such annealing and rolling operations.
- Step B can also be designed as a holding step during heating to step C.
- T s and T gp s are known for all conventional alloys; T gp s is in any case below 180 ° C and T s is for example:
- step B The equilibrium phases precipitated in step B (especially Al 2 Cu for the 2xxx, Mg 2 Si for the 6xxx and MgZn 2 for the 7xxx alloys) are uniformly and densely distributed as 0.5 to 2 ⁇ m particles.
- their interfaces which are incoherent to the aluminum matrix, form the nucleus for the separation of the aluminides of the additional elements from groups IV B to VI B. This results in a dense network of these aluminide deposits.
- the eliminated equilibrium phases then coarsen.
- the duration of the annealing of step C and the temperature in the range between 300 ° C. and T s -30 ° C.
- the aluminides Additional metals should preferably be chosen so that the aluminides Additional metals are excreted as much as possible; the optimal temperature results from the solubility of the aluminides in the aluminum grid on the one hand and from the diffusivity of the corresponding additional elements on the other. If Cr is selected as the additional element, the preferred temperature of the annealing in step C, provided the T s of the alloy in question permits this, is approximately 380 to 420 ° C. With respect to Zr, the corresponding temperature is approximately 350 to 380 ° C.
- the finish rolling to final thickness d has to be carried out as cold rolling at least in a final phase, from 2.5 times the final thickness, with temperatures of up to 220 ° C being tolerable.
- the recrystallizing treatment D is usually an annealing, preferably a continuous continuous annealing.
- the heating rate must be at least 20 ° C / s at least from 220 ° C until the recrystallization threshold is exceeded.
- the recrystallizing treatment D can, however, also be integrated in a hot forming, the same heating instructions being observed.
- the inventive process results in the entire sheet thickness range of 0.5 mm to 5 mm to an almost globular grain having a mean sectional area of about 25 u m 2 to about 100 11m hardly. 2
- a particularly suitable way of bringing the alloy into the process state A in view of the fine-grained nature of the product is that the alloy is solidified in a rugged manner.
- the time between liquidus and solidus should not exceed 5s. Casting rollers, powder metallurgy processes or melt spinning are suitable for this.
- a billet of 350 mm thickness was cast from the alloy AA 7475 with 5.6% Zn, 2.2% Mg, 1.5% Cu, 0.20% Cr, 0.07% Si, 0.10% Fe and 0.05% Ti using an electromagnetic continuous casting mold.
- condition A After a 2-stage homogenization annealing of 3 hours at 470 ° C and 10 hours at 485 ° C (condition A), the ingot was heated to a starting temperature of 400 to 450 ° C for hot rolling.
- the 9 mm thick hot-rolled strip was coiled at 320 to 380 ° C. and cooled at about 20 ° C./h below 150 ° C. (step B).
- the coil was then annealed at 390 to 400 ° C for 8 hours and cooled in still air (step C).
- the 9 mm strip was cold rolled to a final thickness of 2 mm.
- the strip temperature developed to a maximum of 150 ° C.
- the strip was fed to a continuous belt furnace in which the metal was heated to 475 ° C. within 20 s, held at this temperature for 190 s and then quickly cooled again (treatment D).
- the sheet has an average grain area of 32 gm 2, determined on a light microscopic sectional image.
- An electron micrograph (TEM) in the same state shows the resulting structure in FIG. 1 a in a magnification of 10,000 times and in FIG. 1 b in a magnification of 16,000 times.
- the particles have a diameter of approximately 0.03 to 0.5 ⁇ m and an average distance of approximately 0.5 ⁇ m. As can be seen in particular from FIG. 1, they stabilize the grain boundaries and thus prevent the grain from becoming coarser during subsequent hot forming.
- a strip of 8 mm thickness was cast from the same alloy as in Example 1 on a casting and rolling mill of the CASTER I type with a casting speed of 9 mm / s (condition A).
- the tape was coiled at 270 ° C and cooled to 150 ° C within 4 hours (step B).
- step B After a first cold rolling step to 5 mm, the alloy was annealed as a coil at 400 ° C. for 8 hours (step C). It was then cold-rolled to a final thickness of 1.2 mm and recrystallized as in Example 1 (treatment D).
- the resulting mean grain area is approximately 70 ⁇ m ⁇ .
- the alloy from Example 1 was cast on a CASTER I to form a tape 7 mm thick (condition A).
- the strip coiled at 260 ° C cooled to 150 ° C within 4 hours (step B).
- the coil was heated to 400 ° C. within 6 hours and annealed at this temperature for 8 hours (step C).
- the strip was then cold rolled to a final thickness of 1.2 mm and annealed in a continuous strip furnace after a heating time of 16 s at 475 ° C. for 170 s (treatment D).
- Sheet strips were stretched superplastically at 490 ° C at 0.8 mm / minute.
- the resulting elongation at break was 640% of the initial length of 20 mm.
Description
Die Erfindung betrifft ein Verfahren zur Herstellung eines feinkörnig rekristallisierten, zur superplastischen Umformung geeigneten Bleches aus einer aushärtbaren Aluminiumlegierung.The invention relates to a method for producing a fine-grained recrystallized sheet suitable for superplastic forming from a hardenable aluminum alloy.
Als aushärtbare Aluminiumlegierungen gelten diejenigen, bei welche eine Festigkeitserhöhung ausser durch Kaltumformen auch durch Wärmebehandlung herbeigeführt werden kann. Hierzu gehören insbesondere Legierungen vom Typus AIMgSi, AICuMg, AICuMgSi, AIZnMg, AIZnMgCu und Li-haltige Varianten hiervon. Bei diesen Legierungen ist eine Neigung zur Grobkornbildung vorhanden, falls die zur Ausscheidungshärtung nötige Lösungsglühung mit einer Rekristallisation verbunden ist. Für zahlreiche Anwendungen, vor allem für die superplastische Umformung, ist jedoch Feinkörnigkeit erwünscht oder Voraussetzung. So benötigt man bei Blechen, welche superplastisch umgeformt werden sollen, eine Korngrösse von weniger als 25 wm, bevorzugt von weniger als 10 f.l.m. Die Körner sollen zudem nahezu globulitisch vorliegen. Ueberdies darf sich während der superplastischen Umformung, welche bei etwa 500°C durchgeführt wird, auch keine wesentliche Vergröberung der Körner einstellen.The hardenable aluminum alloys are those in which an increase in strength can be brought about not only by cold forming but also by heat treatment. These include, in particular, alloys of the AIMgSi, AICuMg, AICuMgSi, AIZnMg, AIZnMgCu type and Li-containing variants thereof. These alloys have a tendency to form coarse grains if the solution annealing required for precipitation hardening is associated with recrystallization. For numerous applications, especially for superplastic forming, fine grain is desirable or a requirement. For sheet metal which is to be superplastically formed, a grain size of less than 25 wm, preferably less than 10 flm is required. The grains should also be almost globulitic. In addition, no significant coarsening of the grains may occur during the superplastic forming, which is carried out at about 500 ° C.
Zur Bereitstellung superplastisch umformbarer Bleche aus aushärtbaren Aluminiumlegierungen sind einige Verfahrensvorschläge bekannt. So ist dem US-Patent 4 528 042 folgendes Verfahren zu entnehmen:
- Lösungsglühen eines Gussstrangs oberhalb 460°C, Abkühlen mit 11°C/h bis 56°C/h auf 315 bis 370°C, Warmwalzen mit einer Starttemperatur zwischen 315 und 370°C und einer Endtemperatur unterhalb 315°C, Abkühlen auf 93 bis 232°C, Warmwalzen bei niedrigen Temperaturen auf Enddicke und abschliessendes rasches Rekristallisieren.
- Solution annealing of a cast strand above 460 ° C, cooling at 11 ° C / h to 56 ° C / h to 315 to 370 ° C, hot rolling with a start temperature between 315 and 370 ° C and a final temperature below 315 ° C, cooling to 93 to 232 ° C, hot rolling at low temperatures to final thickness and then quick recrystallization.
Dieses und ähnliche Verfahren haben sich jedoch bei Versuchen als recht empfindlich bezüglich der resultierenden Korngrösse -- insbesondere während einer superplastischen Umformung -- auf geringe Variation in der Legierungszusammensetzung und in weiteren Verfahrensparametern erwiesen.However, this and similar processes have proven to be quite sensitive to small variations in the alloy composition and in further process parameters with regard to the resulting grain size - especially during superplastic forming.
Die Erfinder haben sich deshalb die Aufgabe gestellt, ein Verfahren zu schaffen, welches anwendbar auf alle aushärtbaren Aluminiumlegierungstypen mit hoher Sicherheit und weiter Toleranz bezüglich nicht spezifizierter Verfahrensparameter zu einem feinkörnig rekristallisierten, zur superplastischen Umformung geeigneten Bleches führt.The inventors have therefore set themselves the task of creating a process which, when applicable to all hardenable aluminum alloy types, leads to a fine-grained recrystallized sheet suitable for superplastic forming with high security and wide tolerance with regard to unspecified process parameters.
Ertindungsgemäss wird die Aufgabe dadurch gelöst, dass die verwendete Legierung zusätzlich wenigstens eines der Elemente Ti, Zr, Hf, V Nb, Ta, Cr, Mo, W mit einem Gewichtsanteil von insgesamt 0.08 bis 1.5 % enthält und dass die Legierung in einen Zustand A gebracht wird, in welchem sowohl die zur Aushärtung führenden Legierungselemente als auch die genannten Zusatzelemente zumindest grösstenteils in fester Lösung sind, worauf in einem Schritt B die inkohärenten Aushärtungsphasen in einem Temperaturbereich zwischen dem Entmischungszonen-Solvus T gps und dem Solvus der Gleichgewichts-Aushärtungsphasen T s ausgeschieden werden und in einem folgenden Schritt C die Aluminide der genannten Zusatzelemente durch Glühung in einem Temperaturbereich zwischen 300°C und T s-30 °C gleichmässig mit hoher Dichte ausgeschieden werden, wobei etwaige Walzverformungen zwischen dem Zustand A und dem Schritt C bei Temperaturen von höchstens T s-30 °C erfolgen dürfen, dass weiter die Legierung nach dem Schritt C mit mindestens 60 % Dickenabnahme derart zu einem Blech der Dicke d gewalzt wird, dass die Temperatur des Bleches ab einer Dicke von 2.5xd 220°C nicht überschreitet, sowie dass das Blech bei Dicke d zu einer rekristallisierenden Behandlung D derart aufgeheizt wird, dass bis oberhalb der Rekristallisationsschwelle die Aufheizgeschwindigkeit mindestens 20°C/s beträgt.According to the invention, the object is achieved in that the alloy used additionally contains at least one of the elements Ti, Zr, Hf, V Nb, Ta, Cr, Mo, W with a total weight fraction of 0.08 to 1.5% and that the alloy is in a state A is brought, in which both the alloying elements leading to hardening and the additional elements mentioned are at least largely in solid solution, whereupon in a step B the incoherent hardening phases in a temperature range between the separation zone solvus T gp s and the solvus of the equilibrium hardening phases T s are excreted and in a subsequent step C, the aluminides of the additional elements mentioned are uniformly excreted with high density by annealing in a temperature range between 300 ° C. and T s-30 ° C., with any rolling deformations between state A and step C at temperatures of at most T s -30 ° C may continue that Le Government after the step C with at least 60% thickness reduction is so rolled into a sheet of thickness d, the temperature of the sheet from a thickness of 2.5xd 220 ° C does not exceed, and that the sheet with thickness d to a recrystallizing treatment D such is heated up that the heating rate is at least 20 ° C / s up to above the recrystallization threshold.
Bei der Bemessung des Anteils an den genannten Zusatzelementen ist darauf zu ach ten, dass beim Giessen keine groben Primärausscheidungen entstehen können. Dementsprechend kann der Bereich bis zur Obergrenze von 1.5 Gew.-% nur bei hinreichend rascher Erstarrung voll ausgeschöpft werden. Der erfindungsgemässe Anteil an Zusatzelementen kann teilweise oder vollständig bereits in den gewählten aushärtbaren Aluminiumlegierungen gemäss Norm vorhanden sein.When dimensioning the proportion of the additional elements mentioned, care must be taken to ensure that no coarse primary deposits can occur during casting. Accordingly, the range up to the upper limit of 1.5% by weight can only be fully exploited if the solidification is sufficiently rapid. The proportion of additional elements according to the invention can already be present in part or completely in the selected hardenable aluminum alloys according to the standard.
Der Schritt B kann sowohl als Glühung im Temperaturbereich zwischen T gps und T s durchgeführt werden, als auch in Form einer Warmwalzoperation mit Starttemperatur unterhalb T s -30°C und Endtemperatur oberhalb Tgps, oder auch als Kombination solcher Glühungen und Walzoperationen. Ebenso kann der Schritt B als Haltestufe beim Aufheizen zum Schritt C gestaltet werden.The step B can be used as annealing in the temperature range between T s gp and T s are carried out, and in the form of a hot rolling operation at starting temperature below T s -30 ° C and end temperature above TGPS, or as a combination of such annealing and rolling operations. Step B can also be designed as a holding step during heating to step C.
Die charakterischen Temperaturen T s und T gps sind bei allen üblichen Legierungen bekannt; T gps liegt in jedem Fall unter 180°C and T s beträgt beispielsweise:
Die in Schritt B ausgeschiedenen Gleichgewichtsphasen (vor allem AI2Cu bei den 2xxx-, Mg2Si bei den 6xxx- und MgZn2 bei den 7xxx- Legierungen) sind als 0.5 bis 2 µm grosse Partikel gleichmässig dicht verteilt. Deren zur Aluminium-Matrix inkorärenten Grenzflächen bilden zu Beginn des Schrittes C Keimstellen für die Ausscheidung der Aluminide der Zusatzelemente aus den Gruppen IV B bis VI B. Hieraus entsteht ein dichtes Netzwerk dieser Aluminid-Ausscheidungen. Die ausgeschiedenen Gleichgewichtsphasen ihrerseits vergröbern sich anschliessend. Die Dauer der Glühung des Schrittes C, sowie die Temperatur im Rahmen des genannten Bereichs zwischen 300°C und T s -30°C ist bevorzugt so zu wählen, dass die Aluminide der Zusatzmetalle möglichst weitgehend ausgeschieden werden; die optimale Temperatur ergibt dich aus der Löslichkeit der Aluminide im Aluminiumgitter einerseits und aus der Diffusität der entsprechenden Zusatzelemente andererseits. Wird Cr als Zusatzelement gewählt, so beträgt die bevorzugte Temperatur der Glühung im Schritt C, sofern die T s der betreffenden Legierung dies erlaubt, etwa 380 bis 420°C. Bezüglich Zr liegt die entsprechende Temperatur bei etwa 350 bis 380°C.The equilibrium phases precipitated in step B (especially Al 2 Cu for the 2xxx, Mg 2 Si for the 6xxx and MgZn 2 for the 7xxx alloys) are uniformly and densely distributed as 0.5 to 2 µm particles. At the beginning of step C, their interfaces, which are incoherent to the aluminum matrix, form the nucleus for the separation of the aluminides of the additional elements from groups IV B to VI B. This results in a dense network of these aluminide deposits. The eliminated equilibrium phases then coarsen. The duration of the annealing of step C and the temperature in the range between 300 ° C. and T s -30 ° C. should preferably be chosen so that the aluminides Additional metals are excreted as much as possible; the optimal temperature results from the solubility of the aluminides in the aluminum grid on the one hand and from the diffusivity of the corresponding additional elements on the other. If Cr is selected as the additional element, the preferred temperature of the annealing in step C, provided the T s of the alloy in question permits this, is approximately 380 to 420 ° C. With respect to Zr, the corresponding temperature is approximately 350 to 380 ° C.
Das Fertigwalzen auf Enddicke d hat zumindest in einer letzten Phase, ab 2.5-facher Enddicke, als Kaltwalzen zu erfolgen, wobei Temperaturen bis 220°C tolerierbar sind.The finish rolling to final thickness d has to be carried out as cold rolling at least in a final phase, from 2.5 times the final thickness, with temperatures of up to 220 ° C being tolerable.
Die rekristallisierende Behandlung D ist in der Regel eine Glühung, vorzugsweise eine kontinuierliche Durchlaufglühung. Zumindest ab 220°C bis zum Ueberschreiten der Rekristallisationsschwelle muss die Aufheizgeschwindigkeit mindestens 20°C/s betragen. Die rekristallisierende Behandlung D kann jedoch auch in eine Warmumformung integriert sein, wobei dieselbe Aufheizvorschrift zu beachten ist.The recrystallizing treatment D is usually an annealing, preferably a continuous continuous annealing. The heating rate must be at least 20 ° C / s at least from 220 ° C until the recrystallization threshold is exceeded. The recrystallizing treatment D can, however, also be integrated in a hot forming, the same heating instructions being observed.
Das erfindungsgemässe Verfahren führt im ganzen Blechdickenbereich von 0.5 mm bis 5 mm zu einem nahezu globulitischen Korn mit einer mittleren Schnittfläche von etwa 25 um2 bis kaum über 100 11m2.The inventive process results in the entire sheet thickness range of 0.5 mm to 5 mm to an almost globular grain having a mean sectional area of about 25 u m 2 to about 100 11m hardly. 2
Eine im Hinblick auf die Feinkörnigkeit des Produkts besonders geeignete Art, die Legierung in den verfahrensgemässen Zustand A zu bringen, besteht darin, dass die Legierung schroff erstarrt wird. Hierbei soll die Zeitspanne zwischen Liquidus und Solidus 5s nicht überschreiten. Dazu eignet sich beispielsweise Giesswalzen, pulvermetallurgische Verfahren oder melt spinning.A particularly suitable way of bringing the alloy into the process state A in view of the fine-grained nature of the product is that the alloy is solidified in a rugged manner. The time between liquidus and solidus should not exceed 5s. Casting rollers, powder metallurgy processes or melt spinning are suitable for this.
Weitere Vorteile, Merkmale und Einzelheiten der Erfindung ergeben sich aus der nachfolgenden Beschreibung bevorzugter Ausführungsbeispiele.Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments.
Aus der Legierung AA 7475 mit 5.6% Zn, 2.2% Mg, 1.5% Cu, 0.20% Cr, 0.07% Si, 0.10% Fe und 0.05 % Ti wurde mittels einer elektromagnetischen Stranggusskokille ein Walzbarren von 350 mm Dicke gegossen. Nach einer 2-stufigen Homogenisierungsglühung von 3 Stunden bei 470°C und 10 Stunden bei 485°C (Zustand A) wurde der Barren zum Warmwalzen auf eine Starttemperatur von 400 bis 450°C aufgewärmt. Das 9 mm dicke Warmwalzband wurde bei 320 bis 380°C gehaspelt und mit etwa 20°C/h unter 150°C abgekühlt (Schritt B). Der Bund wurde sodann bei 390 bis 400°C während 8 Stunden geglüht und an ruhender Luft abgekühlt (Schritt C). Das 9 mm-Band wurde auf eine Enddicke von 2 mm kaltgewalzt. Dabei entwickelte sich eine Bandtemperatur von höchstens 150°C. Das Band wurde einem Banddurchlaufofen zugeführt, in welchem das Metall innert 20s auf 475°C aufgewärmt, bei dieser Temperatur während 190s gehalten und anschliessend wieder rasch abgekühlt wurde (Behandlung D).A billet of 350 mm thickness was cast from the alloy AA 7475 with 5.6% Zn, 2.2% Mg, 1.5% Cu, 0.20% Cr, 0.07% Si, 0.10% Fe and 0.05% Ti using an electromagnetic continuous casting mold. After a 2-stage homogenization annealing of 3 hours at 470 ° C and 10 hours at 485 ° C (condition A), the ingot was heated to a starting temperature of 400 to 450 ° C for hot rolling. The 9 mm thick hot-rolled strip was coiled at 320 to 380 ° C. and cooled at about 20 ° C./h below 150 ° C. (step B). The coil was then annealed at 390 to 400 ° C for 8 hours and cooled in still air (step C). The 9 mm strip was cold rolled to a final thickness of 2 mm. The strip temperature developed to a maximum of 150 ° C. The strip was fed to a continuous belt furnace in which the metal was heated to 475 ° C. within 20 s, held at this temperature for 190 s and then quickly cooled again (treatment D).
Das Blech weist, auf einem lichtmikroskopischen Schnittbild ermittelt, eine durchschnittene Kornfläche von 32 gm2 auf. Eine elektronenmikroskopische Aufnahme (TEM) im selben Zustand zeigt in Figur 1 a in 10000-facher und in Figur 1 b in 16000-facher Vergrösserung das resultierende Gefüge. Daraus ist die feindisperse Verteilung der Aluminide, vornehmlich die ternäre Phase Al18Mg3Cr2, ersichtlich. Die Partikel weisen einen Durchmesser von etwa 0.03 bis 0.5 µm und einen mittleren Abstand von etwa 0.5 µm auf. Sie stabilisieren, wie insbesondere aus Figur 1 hervorgeht, die Korngrenzen und verhindern so die Kornvergröberung bei nachfolgenden Warmumformungen.The sheet has an average grain area of 32 gm 2, determined on a light microscopic sectional image. An electron micrograph (TEM) in the same state shows the resulting structure in FIG. 1 a in a magnification of 10,000 times and in FIG. 1 b in a magnification of 16,000 times. This shows the finely dispersed distribution of the aluminides, primarily the ternary phase Al 18 Mg 3 Cr 2 . The particles have a diameter of approximately 0.03 to 0.5 µm and an average distance of approximately 0.5 µm. As can be seen in particular from FIG. 1, they stabilize the grain boundaries and thus prevent the grain from becoming coarser during subsequent hot forming.
Die 2 mm dicken Bleche wurden daraufhin bei 500°C mit einer Umformgeschwindigkeit von 10-3/s erfolgreich zu umgeformten Teilen gefertigt. Eine Kornvergröberung konnte nicht festgestellt werden.The 2 mm thick sheets were then / s successfully made at 500 ° C with a strain rate of 10- 3 to formed parts. A grain coarsening could not be found.
Aus derselben Legierung wie in Beispiel 1 wurde auf einer Giesswalzanlage vom Typus CASTER I mit einer Giessgeschwindigkeit von 9 mm/s ein Band von 8 mm Dicke gegossen (Zustand A). Das Band wurde bei 270°C gehaspelt und innert 4 Stunden auf 150°C abgekühlt (Schritt B). Nach einem ersten Kaltwalzschritt auf 5 mm wurde die Legierung als Bund bei 400°C während 8 Stunden geglüht (Schritt C). Anschliessend wurde auf Enddicke 1.2 mm kaltgewalzt und wie im Beispiel 1 rekristallisiert (Behandlung D).A strip of 8 mm thickness was cast from the same alloy as in Example 1 on a casting and rolling mill of the CASTER I type with a casting speed of 9 mm / s (condition A). The tape was coiled at 270 ° C and cooled to 150 ° C within 4 hours (step B). After a first cold rolling step to 5 mm, the alloy was annealed as a coil at 400 ° C. for 8 hours (step C). It was then cold-rolled to a final thickness of 1.2 mm and recrystallized as in Example 1 (treatment D).
Die resultierende mittlere Kornfläche beträgt etwa 70 µmε.The resulting mean grain area is approximately 70 µ m ε.
Die Legierung aus Beispiel 1 wurde auf einem CASTER I zu einem Band von 7 mm Dicke vergossen (Zustand A). Das bei 260°C gehaspelte Band kühlte innert 4 Stunden auf 150°C ab (Schritt B). Der Bund wurde innert 6 Stunden auf 400°C aufgewärmt und bei dieser Temperatur 8 Stunden geglüht (Schritt C). Das Band wurde sodann auf die Enddicke von 1.2 mm kaltgewalzt und im Banddurchlaufofen nach einer Aufheizzeit von 16s bei 475°C während 170s geglüht (Behandlung D).The alloy from Example 1 was cast on a CASTER I to form a tape 7 mm thick (condition A). The strip coiled at 260 ° C cooled to 150 ° C within 4 hours (step B). The coil was heated to 400 ° C. within 6 hours and annealed at this temperature for 8 hours (step C). The strip was then cold rolled to a final thickness of 1.2 mm and annealed in a continuous strip furnace after a heating time of 16 s at 475 ° C. for 170 s (treatment D).
Dies führte zu einer mittleren Kornfläche von 28 wm2.This resulted in an average grain area of 28 w m2 .
Blechstreifen wurden bei 490°C im Zugversuch superplastisch mit 0.8 mm/Minute gedehnt. Die resultierende Bruchdehnung betrug 640 % der Ausgangslänge von 20 mm.Sheet strips were stretched superplastically at 490 ° C at 0.8 mm / minute. The resulting elongation at break was 640% of the initial length of 20 mm.
Claims (2)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH390886 | 1986-09-30 | ||
CH3908/86 | 1986-09-30 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0263070A1 EP0263070A1 (en) | 1988-04-06 |
EP0263070B1 true EP0263070B1 (en) | 1990-10-17 |
Family
ID=4266089
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP87810554A Expired - Lifetime EP0263070B1 (en) | 1986-09-30 | 1987-09-24 | Process for the production of a fine-grained recrystallised sheet |
Country Status (4)
Country | Link |
---|---|
US (1) | US4797164A (en) |
EP (1) | EP0263070B1 (en) |
CA (1) | CA1312262C (en) |
DE (1) | DE3765611D1 (en) |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2664618B1 (en) * | 1990-07-10 | 1993-10-08 | Pechiney Aluminium | PROCESS FOR THE MANUFACTURE OF CATHODES FOR CATHODE SPRAYING BASED ON VERY HIGH PURITY ALUMINUM. |
WO1999064854A1 (en) | 1998-06-09 | 1999-12-16 | Tosoh Smd, Inc. | Method and apparatus for quantitative sputter target cleanliness characterization |
IL156386A0 (en) * | 2000-12-21 | 2004-01-04 | Alcoa Inc | Aluminum alloy products and artificial aging method |
DE60239054D1 (en) * | 2001-04-04 | 2011-03-10 | Tosoh Smd Inc | METHOD FOR DETERMINING THE CRITICAL SIZE OF AN INCLUSION IN A SPUTTER TARGET OF ALUMINUM OR ALUMINUM ALLOY |
ES2238584T3 (en) * | 2001-07-09 | 2005-09-01 | Corus Aluminium Walzprodukte Gmbh | HIGH-RESISTANCE AL-MG-SI ALLOY. |
DE10323741B3 (en) * | 2003-05-24 | 2004-10-14 | Daimlerchrysler Ag | Aluminum casting alloy for the production of e.g. pistons of IC engines contains alloying additions of silicon, magnesium, zirconium, hafnium and titanium |
US6959476B2 (en) * | 2003-10-27 | 2005-11-01 | Commonwealth Industries, Inc. | Aluminum automotive drive shaft |
WO2009132436A1 (en) * | 2008-04-28 | 2009-11-05 | University Of Waterloo | Thermomechanical process for treating alloys |
CN103119185B (en) | 2010-09-08 | 2015-08-12 | 美铝公司 | The 7XXX aluminium alloy improved and production method thereof |
WO2013172910A2 (en) | 2012-03-07 | 2013-11-21 | Alcoa Inc. | Improved 2xxx aluminum alloys, and methods for producing the same |
US9587298B2 (en) | 2013-02-19 | 2017-03-07 | Arconic Inc. | Heat treatable aluminum alloys having magnesium and zinc and methods for producing the same |
CN111057975B (en) * | 2019-12-23 | 2021-03-05 | 中国航空制造技术研究院 | Preparation method of aluminum-lithium alloy superplastic fine-grain plate |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3706606A (en) * | 1970-02-10 | 1972-12-19 | L Esercizio Dell Inst Sperimen | Thermomechanical treatment process for heat treatable aluminium alloys |
US4092181A (en) * | 1977-04-25 | 1978-05-30 | Rockwell International Corporation | Method of imparting a fine grain structure to aluminum alloys having precipitating constituents |
US4222797A (en) * | 1979-07-30 | 1980-09-16 | Rockwell International Corporation | Method of imparting a fine grain structure to aluminum alloys having precipitating constituents |
US4528042A (en) * | 1983-03-28 | 1985-07-09 | Reynolds Metals Company | Method for producing superplastic aluminum alloys |
-
1987
- 1987-09-22 US US07/099,746 patent/US4797164A/en not_active Expired - Fee Related
- 1987-09-24 DE DE8787810554T patent/DE3765611D1/en not_active Expired - Fee Related
- 1987-09-24 EP EP87810554A patent/EP0263070B1/en not_active Expired - Lifetime
- 1987-09-28 CA CA000547946A patent/CA1312262C/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
DE3765611D1 (en) | 1990-11-22 |
CA1312262C (en) | 1993-01-05 |
US4797164A (en) | 1989-01-10 |
EP0263070A1 (en) | 1988-04-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE69326838T3 (en) | TOUGH ALUMINUM ALLOY WITH COPPER AND MAGNESIUM | |
DE1558521C3 (en) | Use of a nickel-chromium wrought alloy as a superplastic material | |
DE69125436T3 (en) | Method of producing aluminum alloy sheet | |
DE112008003052T5 (en) | Product of Al-Mg-Zn wrought alloy and manufacturing method therefor | |
DE3445767A1 (en) | Method of forging nickel-base superalloys and a nickel-base superalloy article having improved forgeability | |
EP0263070B1 (en) | Process for the production of a fine-grained recrystallised sheet | |
DE3411760A1 (en) | METHOD FOR PRODUCING SHEET OR STRIP FROM A ROLLING BAR OF AN ALUMINUM ALLOY | |
DE69916456T2 (en) | HIGHLY CONDUCTIVE ALUMINUM ALLOY FOR COOLING RIBS | |
DE2223114A1 (en) | Process for the heat treatment of alloys on a nickel-iron basis and especially suitable alloys for this | |
EP0062469B1 (en) | Method for producing fine-grained, high strength aluminum alloy material | |
DE2606632C2 (en) | Use of carbon steel as a superplastic agent and process for its heat treatment | |
DE2551294B2 (en) | Process for making dispersion strengthened aluminum alloy products | |
DE2551295A1 (en) | ALUMINUM ALLOY PRODUCTS AND THEIR MANUFACTURE | |
WO2003052154A1 (en) | Method for the production of a highly fracture-resistant aluminium sheet material alloyed with scandium (sc) and/or zirconium (zr) | |
DE3411762C2 (en) | ||
EP1330556A1 (en) | Method for producing a magnesium hot strip | |
EP0462056A1 (en) | Aluminium alloy superplastic strip | |
EP0140827B1 (en) | Process for the manufacture of fine grain-textured aluminium rolling mill products | |
DE2235168C2 (en) | Process for the production of aluminum alloys and their use | |
EP3638820A1 (en) | Monotectic aluminum plain bearing alloy, method for producing same, and plain bearing produced therewith | |
WO1999015708A1 (en) | Aluminium based alloy and method for subjecting it to heat treatment | |
DE2751623A1 (en) | PROCESS FOR THE MANUFACTURING OF HOT DEFORMED PRODUCTS FROM MOLYBDAEN AND MOLYBDAEN ALLOYS | |
EP0297035B1 (en) | Aluminium alloy for superplastic deformation | |
DE2242235C3 (en) | Superplastic aluminum alloy | |
DE69921146T2 (en) | METHOD FOR THE PRODUCTION OF HEAT-TREATABLE PANEL OBJECTS |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): BE CH DE FR GB IT LI NL SE |
|
17P | Request for examination filed |
Effective date: 19880903 |
|
17Q | First examination report despatched |
Effective date: 19891117 |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: ALUSUISSE-LONZA SERVICES AG |
|
ITF | It: translation for a ep patent filed |
Owner name: DE DOMINICIS & MAYER S.R.L. |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): BE CH DE FR GB IT LI NL SE |
|
GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) | ||
REF | Corresponds to: |
Ref document number: 3765611 Country of ref document: DE Date of ref document: 19901122 |
|
ET | Fr: translation filed | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
ITTA | It: last paid annual fee | ||
26N | No opposition filed | ||
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19940818 Year of fee payment: 8 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 19940902 Year of fee payment: 8 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 19940907 Year of fee payment: 8 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 19940913 Year of fee payment: 8 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 19940930 Year of fee payment: 8 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 19941010 Year of fee payment: 8 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 19941109 Year of fee payment: 8 |
|
EAL | Se: european patent in force in sweden |
Ref document number: 87810554.3 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19950924 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Effective date: 19950925 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Effective date: 19950930 Ref country code: CH Effective date: 19950930 Ref country code: BE Effective date: 19950930 |
|
BERE | Be: lapsed |
Owner name: ALUSUISSE-LONZA SERVICES A.G. Effective date: 19950930 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Effective date: 19960401 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19950924 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19960531 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19960601 |
|
NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee |
Effective date: 19960401 |
|
EUG | Se: european patent has lapsed |
Ref document number: 87810554.3 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED. Effective date: 20050924 |