ITTO20130531A1 - METHOD FOR THE MANUFACTURE OF COMPOSITES WITH ALUMINUM MATRIX VIA INFILTRATION WITHOUT PRESSURE - Google Patents

METHOD FOR THE MANUFACTURE OF COMPOSITES WITH ALUMINUM MATRIX VIA INFILTRATION WITHOUT PRESSURE

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Publication number
ITTO20130531A1
ITTO20130531A1 IT000531A ITTO20130531A ITTO20130531A1 IT TO20130531 A1 ITTO20130531 A1 IT TO20130531A1 IT 000531 A IT000531 A IT 000531A IT TO20130531 A ITTO20130531 A IT TO20130531A IT TO20130531 A1 ITTO20130531 A1 IT TO20130531A1
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IT
Italy
Prior art keywords
aluminum
preform
infiltration
reinforcement
composite
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Application number
IT000531A
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Italian (it)
Inventor
Claudio Francesco Badini
Sara Biamino
Xiang Chen
Paolo Fino
Matteo Pavese
Wenshu Yang
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Torino Politecnico
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Application filed by Torino Politecnico filed Critical Torino Politecnico
Priority to IT000531A priority Critical patent/ITTO20130531A1/en
Publication of ITTO20130531A1 publication Critical patent/ITTO20130531A1/en
Priority to PCT/IT2014/000168 priority patent/WO2014207776A1/en

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    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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    • C22C1/00Making non-ferrous alloys
    • C22C1/10Alloys containing non-metals
    • C22C1/1005Pretreatment of the non-metallic additives
    • C22C1/1015Pretreatment of the non-metallic additives by preparing or treating a non-metallic additive preform
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    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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    • C22C1/00Making non-ferrous alloys
    • C22C1/10Alloys containing non-metals
    • C22C1/1005Pretreatment of the non-metallic additives
    • C22C1/1015Pretreatment of the non-metallic additives by preparing or treating a non-metallic additive preform
    • C22C1/1021Pretreatment of the non-metallic additives by preparing or treating a non-metallic additive preform the preform being ceramic
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    • C22C1/1036Alloys containing non-metals starting from a melt
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    • C22C29/02Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C22C29/06Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
    • C22C29/062Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds based on B4C
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    • C22C29/00Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
    • C22C29/02Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C22C29/06Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
    • C22C29/065Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds based on SiC
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    • C22C29/02Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C22C29/06Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
    • C22C29/10Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds based on titanium carbide
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    • C22C29/12Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on oxides
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    • C22C29/16Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on nitrides
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    • C22C32/001Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides
    • C22C32/0015Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides with only single oxides as main non-metallic constituents
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    • C22C32/0047Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
    • C22C32/0052Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only carbides
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    • C22C32/0047Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
    • C22C32/0052Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only carbides
    • C22C32/0057Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only carbides based on B4C
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    • C22C32/0047Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
    • C22C32/0052Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only carbides
    • C22C32/0063Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only carbides based on SiC
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    • C22C32/0047Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
    • C22C32/0068Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only nitrides
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    • C22C32/0073Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only borides

Description

Descrizione dell’Invenzione Industriale avente per titolo: Description of the Industrial Invention entitled:

“Metodo per la fabbricazione di compositi a matrice di alluminio tramite infiltrazione senza pressione” "Method for manufacturing aluminum matrix composites by pressure-free infiltration"

DESCRIZIONE DESCRIPTION

La presente invenzione si riferisce ad un metodo per la fabbricazione di compositi a matrice di alluminio tramite infiltrazione senza pressione. The present invention relates to a method for manufacturing aluminum matrix composites by pressure-free infiltration.

I compositi a matrice di alluminio possiedono elevata rigidità specifica ed elevata robustezza specifica, buone proprietà ad alta temperatura, buona resistenza a fatica ed usura, buona capacità di smorzamento e basso coefficiente di espansione termica. Come qualsiasi altro composito, esso può combinare proprietà meccaniche e fisiche specifiche per soddisfare i requisiti applicativi. Di conseguenza, i compositi a matrice di alluminio sono diventati uno dei compositi a matrice metallica più comuni ed importanti. Aluminum matrix composites possess high specific stiffness and high specific strength, good high temperature properties, good fatigue and wear resistance, good damping capacity and low coefficient of thermal expansion. Like any other composite, it can combine specific mechanical and physical properties to meet application requirements. As a result, aluminum matrix composites have become one of the most common and important metal matrix composites.

I compositi a matrice di alluminio sono di solito fabbricati tramite il trattamento di colata sotto pressione, metallurgia delle polveri, infiltrazione sotto pressione, colata per agitazione e infiltrazione senza pressione o infiltrazione spontanea. Tra loro, il trattamento di infiltrazione senza pressione ha un maggior potenziale per l’applicazione industriale per il suo processo semplice, il basso costo e il fatto di non avere alcuna limitazione sulla dimensione o la forma dei prodotti. La limitazione principale per questo trattamento è il suo campo di applicazione. L’applicazione dell’infiltrazione senza pressione dipende significativamente dalla bagnabilità tra materiale di rinforzo ed alluminio o leghe di alluminio fusi, ma di solito la bagnabilità è relativamente scarsa per i rinforzi ceramici utilizzati comunemente (quale l’ossido di alluminio) e l’alluminio o le leghe di alluminio fusi. Esistono tre tipi principali di metodi per migliorare la bagnabilità in modo da indurre l’infiltrazione spontaneamente: uno è tramite la modifica della composizione della matrice tramite l’aggiunta di certi elementi leganti (ad esempio magnesio o litio che sono comunemente applicati a questo scopo); un altro è tramite la modifica delle proprietà superficiali del rinforzo tramite il rivestimento della sua superficie con un agente di miglioramento dell’infiltrazione (ad esempio nichel o nitruro di titanio) o la formazione di un agente di miglioramento dell’infiltrazione (ad esempio spinello magnesio-alluminio o nitruro di alluminio) all’interfaccia tra il rinforzo e la matrice; l’ultimo è tramite l’introduzione di una reazione prima o durante l’infiltrazione, che cambia la composizione chimica del rinforzo o del metallo della matrice, che è anche definita come infiltrazione reattiva. Inoltre, un tipo speciale di infiltrazione senza pressione può essere generato attraverso la generazione di vuoto nel sistema oppure generando un vuoto interno tramite il consumo di un gas interno reattivo. Aluminum matrix composites are usually fabricated by pressure casting treatment, powder metallurgy, pressure infiltration, agitation casting, and pressure-free infiltration or spontaneous infiltration. Among them, the pressure-free infiltration treatment has a greater potential for industrial application due to its simple process, low cost and the fact that it has no limitations on the size or shape of the products. The main limitation for this processing is its scope. The application of pressure-free infiltration depends significantly on the wettability between the reinforcing material and molten aluminum or aluminum alloys, but usually the wettability is relatively poor for commonly used ceramic reinforcements (such as aluminum oxide) and aluminum or cast aluminum alloys. There are three main types of methods to improve wettability in order to induce infiltration spontaneously: one is by modifying the composition of the matrix by adding certain alloying elements (e.g. magnesium or lithium which are commonly applied for this purpose) ; another is by modifying the surface properties of the reinforcement by coating its surface with an infiltration enhancing agent (e.g. nickel or titanium nitride) or by forming an infiltration enhancing agent (e.g. spinel magnesium - aluminum or aluminum nitride) at the interface between the reinforcement and the matrix; the latter is through the introduction of a reaction before or during infiltration, which changes the chemical composition of the reinforcement or of the metal of the matrix, which is also defined as reactive infiltration. In addition, a special type of pressureless infiltration can be generated by generating a vacuum in the system or by generating an internal vacuum by consuming a reactive internal gas.

Il brevetto statunitense No. 5509555 descrive un metodo per produrre un articolo tramite infiltrazione reattiva senza pressione. In quest’invenzione, una preforma porosa contenente almeno carbonio può essere infiltrata da leghe infiltranti liquide contenenti almeno due elementi tra Al e Si oppure Cu e Si. La bagnabilità è ottenuta insieme al processo di infiltrazione grazie alla formazione di carburo di silicio. Esistono limiti composizionali sia per la preforma (deve contenere carbonio) sia per le leghe infiltranti (Al-Si oppure Cu-Si), il che limita notevolmente la sua applicazione. Inoltre, la temperatura richiesta in questo brevetto è relativamente elevata (900<o>C-1800<o>C), di solito superiore a 900<o>C, dando come risultato un elevato costo di produzione. U.S. Patent No. 5509555 discloses a method of producing an article by pressure-free reactive infiltration. In this invention, a porous preform containing at least carbon can be infiltrated by liquid infiltrating alloys containing at least two elements between Al and Si or Cu and Si. The wettability is obtained together with the infiltration process thanks to the formation of silicon carbide. There are compositional limits both for the preform (it must contain carbon) and for the infiltrating alloys (Al-Si or Cu-Si), which considerably limits its application. Furthermore, the temperature applied for in this patent is relatively high (900 <o> C-1800 <o> C), usually above 900 <o> C, resulting in a high production cost.

Il Brevetto Europeo No. 0291441 descrive un metodo per realizzare un composito a matrice di alluminio tramite infiltrazione spontanea di una massa permeabile di riempitivo ceramico con alluminio fuso, dove la lega di alluminio della matrice contiene almeno circa l’1 per cento in peso di magnesio, e il processo avviene in un’atmosfera contenente dal 10 al 100% in volume di azoto, essendo il rimanente gas non ossidante, con la temperatura compresa tra 700<o>C e 1200<o>C. I compositi a matrice di alluminio prodotti contengono tipicamente nitruro di alluminio nella matrice di alluminio come fase discontinua, che si forma durante l’infiltrazione grazie alla reazione tra la matrice di alluminio (anche grazie alla presenza di magnesio) e l’atmosfera di azoto, e si ritiene che abbia un effetto positivo sull’infiltrazione spontanea. Il controllo richiesto dell’atmosfera e della composizione della lega della matrice complicano il processo, aumentano il costo di produzione e limitano l’applicazione (soltanto una lega di alluminio contenente magnesio può servire come matrice). The European Patent No. 0291441 describes a method for making an aluminum matrix composite by spontaneous infiltration of a permeable mass of ceramic filler with molten aluminum, where the aluminum alloy of the matrix contains at least about 1 percent by weight of magnesium. , and the process takes place in an atmosphere containing from 10 to 100% by volume of nitrogen, the remaining gas being non-oxidizing, with the temperature between 700 <o> C and 1200 <o> C. The aluminum matrix composites produced typically contain aluminum nitride in the aluminum matrix as a discontinuous phase, which is formed during infiltration thanks to the reaction between the aluminum matrix (also thanks to the presence of magnesium) and the nitrogen atmosphere, and is believed to have a positive effect on spontaneous infiltration. The required control of the atmosphere and of the alloy composition of the matrix complicate the process, increase the cost of production and limit the application (only an aluminum alloy containing magnesium can serve as a matrix).

Il Brevetto Europeo No. 0115742 descrive un componente di celle elettrolitiche per la produzione di alluminio con una struttura composita di una matrice pre-formata di ceramica infiltrata da alluminio. Esso prevede un modo per rendere bagnabile da parte dell’alluminio fuso un materiale non bagnabile (quale ossido di alluminio) tramite pre-rivestimento di un agente bagnante sulla sua superficie. L’agente bagnante può essere scelto tra litio, magnesio, calcio, titanio, cromo, ferro, cobalto, nichel, zirconio o afnio ed i diboruri di titanio, zirconio, afnio e niobio. Tuttavia, il processo di pre-rivestimento aumenterebbe notevolmente il costo dell’apparecchiatura e della produzione. Inoltre, la temperatura richiesta è di solito troppo elevata (con rivestimento di Ni, 1200<o>C per 12 ore) cosicché esso non è adatto per un’applicazione commerciale. European Patent No. 0115742 describes a component of electrolytic cells for the production of aluminum with a composite structure of a pre-formed matrix of aluminum infiltrated ceramic. It provides a way to make a non-wettable material (such as aluminum oxide) wettable by molten aluminum by pre-coating a wetting agent on its surface. The wetting agent can be chosen from lithium, magnesium, calcium, titanium, chromium, iron, cobalt, nickel, zirconium or hafnium and the diborides of titanium, zirconium, hafnium and niobium. However, the pre-coating process would significantly increase the cost of equipment and production. Furthermore, the required temperature is usually too high (with Ni coating, 1200 <o> C for 12 hours) so that it is not suitable for a commercial application.

Il Brevetto Europeo No. 0368784 descrive un metodo per fabbricare compositi a matrice metallica tramite infiltrazione spontanea del materiale riempitivo o della preforma con metalli fusi, dove si ritiene che l’infiltrazione sia indotta dalla comunicazione tra l’atmosfera di infiltrazione e il materiale riempitivo o la preforma, o il metallo della matrice, che fornirebbe un agente di miglioramento dell’infiltrazione o un suo precursore all’interfaccia tra matrice e riempitivo. Come sviluppo del documento EP0291441, questo brevetto allarga significativamente l’applicazione. Il punto saliente è tuttavia dato dalla necessità della presenza di azoto insieme ad un precursore di un agente di miglioramento dell’infiltrazione, quale magnesio/stronzio, oppure della presenza di ossigeno insieme a zinco/calcio, che permette alla matrice fusa di alluminio di infiltrare spontaneamente il riempitivo. Analogamente al documento EP0291441, si ottiene la bagnabilità contemporaneamente all’infiltrazione durante la formazione dell’agente di miglioramento dell’infiltrazione. Il controllo richiesto dell’atmosfera e della composizione della lega della matrice complica il processo, aumenta il costo di produzione e limita l’applicazione. European Patent No. 0368784 describes a method of fabricating metal matrix composites by spontaneous infiltration of the filler material or preform with molten metals, where infiltration is believed to be induced by communication between the infiltrating atmosphere and the filler material or the preform, or matrix metal, which would provide an infiltration enhancing agent or precursor thereof at the matrix-filler interface. As a development of document EP0291441, this patent significantly broadens the application. The salient point, however, is given by the need for the presence of nitrogen together with a precursor of an agent for improving infiltration, such as magnesium / strontium, or the presence of oxygen together with zinc / calcium, which allows the molten aluminum matrix to infiltrate the filler spontaneously. Similarly to document EP0291441, wettability is obtained simultaneously with infiltration during the formation of the infiltration improvement agent. The required control of the atmosphere and of the alloy composition of the matrix complicates the process, increases the cost of production and limits the application.

Il Brevetto Europeo No. 1178127 descrive un metodo per produrre un composito a matrice metallica per infiltrazione senza pressione, senza il controllo dell’atmosfera. In questo brevetto, un metallo di accelerazione dell’infiltrazione (magnesio) ed un riempitivo di rinforzo (carburo di silicio) sono caricati in un contenitore di alluminio con il 30%-70% di spazio pieno d’aria; quindi, il contenitore di alluminio viene sigillato e fuso in una fusione di metallo di matrice. Dopo l’infiltrazione, avviene la solidificazione del metallo del bagno di fusione e della matrice e si ottiene un composito. In questo brevetto, il contenitore di alluminio sigillato con aria residua all’interno genera una pressione ad alta temperatura che contribuisce all’infiltrazione iniziale, ed i prodotti di reazione di magnesio ed aria migliorano la bagnabilità e contribuiscono all’infiltrazione finale. Analogamente ai documenti EP0368784 ed EP0291441, è richiesta la presenza di azoto/ossigeno e del precursore dell’agente di miglioramento dell’infiltrazione, inoltre in questo brevetto è previsto un contenitore di alluminio sigillato con il 30%-70% di aria per controllare l’atmosfera, il che potrebbe semplificare il processo e ridurre il costo di produzione. Tuttavia, in questo brevetto, il composito prodotto si raffredda insieme al bagno del metallo della matrice, il che rende difficile separarlo dalla matrice solidificata. Analogamente al documento EP0368784, grazie alla presenza di ossigeno ed azoto, il metallo di accelerazione dell’infiltrazione è scelto tra un metallo contenente magnesio, calcio o zirconio. L’aggiunta di questo tipo di metallo di accelerazione dell’infiltrazione probabilmente modifica la composizione finale del materiale della matrice. The European Patent No. 1178127 describes a method for producing a metal matrix composite by infiltration without pressure, without controlling the atmosphere. In this patent, an infiltration acceleration metal (magnesium) and a reinforcing filler (silicon carbide) are loaded into an aluminum container with 30% -70% of air-filled space; then, the aluminum container is sealed and melted into a matrix metal casting. After infiltration, solidification of the metal of the melt bath and of the matrix takes place and a composite is obtained. In this patent, the sealed aluminum container with residual air inside generates a high temperature pressure that contributes to the initial infiltration, and the reaction products of magnesium and air improve wettability and contribute to the final infiltration. Similarly to documents EP0368784 and EP0291441, the presence of nitrogen / oxygen and the precursor of the infiltration enhancing agent is required, furthermore in this patent an aluminum container sealed with 30% -70% air is provided to control the atmosphere, which could simplify the process and reduce the cost of production. However, in this patent, the composite produced cools together with the metal bath of the matrix, which makes it difficult to separate it from the solidified matrix. Similarly to document EP0368784, thanks to the presence of oxygen and nitrogen, the infiltration acceleration metal is chosen from a metal containing magnesium, calcium or zirconium. The addition of this type of infiltration acceleration metal probably modifies the final composition of the matrix material.

Scopo della presente invenzione è risolvere i suddetti problemi della tecnica anteriore, fornendo un processo semplificato per il controllo flessibile della percentuale di rinforzo e per migliorare ulteriormente il campo di applicazione della tecnologia dell’infiltrazione senza pressione, e così si prevede nella presente invenzione un nuovo approccio per fabbricare compositi a matrice di alluminio, in cui la maggior parte dei materiali di rinforzo quali ossidi (ossido di alluminio, ossido di silicio, ecc.), carburi (SiC, TiC, B4C ecc.), boruri (TiB2, AlB, MgB2), nitruri (AlN, TiN, Si3N4) possono essere infiltrati senza pressione tramite alluminio o leghe di alluminio fusi in un campo di temperature di 700<o>C-1500<o>C, tramite il mescolamento con una quantità sufficiente di polvere di alluminio o di lega di alluminio, in un ambiente protettivo quale un’atmosfera di azoto, argo o vuoto. The object of the present invention is to solve the aforementioned problems of the prior art, by providing a simplified process for flexible control of the percentage of reinforcement and to further improve the field of application of the pressure-less infiltration technology, and thus a new invention is envisaged in the present invention. approach to fabricate aluminum matrix composites, in which most of the reinforcing materials such as oxides (aluminum oxide, silicon oxide, etc.), carbides (SiC, TiC, B4C etc.), borides (TiB2, AlB, MgB2), nitrides (AlN, TiN, Si3N4) can be infiltrated without pressure through molten aluminum or aluminum alloys in a temperature range of 700 <o> C-1500 <o> C, by mixing with a sufficient amount of powder aluminum or aluminum alloy, in a protective environment such as a nitrogen, argon or vacuum atmosphere.

I suddetti ed altri scopi e vantaggi dell’invenzione, quali risulteranno dal seguito della descrizione, vengono raggiunti con un metodo per la fabbricazione di compositi a matrice di alluminio tramite infiltrazione senza pressione come quello descritto nella rivendicazione 1. Forme di realizzazione preferite e varianti non banali della presente invenzione formano l’oggetto delle rivendicazioni dipendenti. The above and other objects and advantages of the invention, as will emerge from the following description, are achieved with a method for the manufacture of aluminum matrix composites by pressureless infiltration such as that described in claim 1. Preferred embodiments and variants not banal elements of the present invention form the subject of the dependent claims.

Resta inteso che tutte le rivendicazioni allegate formano parte integrante della presente descrizione. It is understood that all the attached claims form an integral part of the present description.

La presente invenzione verrà meglio descritta da alcune forme preferite di realizzazione, fornite a titolo esemplificativo e non limitativo, con riferimento ai disegni allegati, in cui: The present invention will be better described by some preferred embodiments, provided by way of non-limiting example, with reference to the attached drawings, in which:

- la Figura 1 è una vista schematica in sezione laterale di un crogiuolo in cui si può realizzare l’esempio 1 del metodo della presente invenzione; - Figure 1 is a schematic side section view of a crucible in which example 1 of the method of the present invention can be realized;

- la Figura 2 è una vista schematica in sezione laterale di un crogiuolo in cui si può realizzare l’esempio 2 del metodo della presente invenzione; e - Figure 2 is a schematic side section view of a crucible in which example 2 of the method of the present invention can be realized; And

- la Figura 3 è un diagramma schematico delle principali fasi del metodo secondo la presente invenzione. Figure 3 is a schematic diagram of the main steps of the method according to the present invention.

Facendo riferimento alle Figure, è illustrata e descritta una forma di realizzazione preferita del metodo per la fabbricazione di compositi a matrice di alluminio tramite infiltrazione senza pressione della presente invenzione. Risulterà immediatamente ovvio che si potranno apportare a quanto descritto innumerevoli varianti e modifiche (per esempio relative a forma, dimensioni, disposizioni e parti con funzionalità equivalenti) senza discostarsi dal campo di protezione dell'invenzione come appare dalle rivendicazioni allegate. With reference to the Figures, a preferred embodiment of the method for manufacturing aluminum matrix composites by pressure-less infiltration of the present invention is illustrated and described. It will be immediately obvious that innumerable variations and modifications (for example relating to shape, dimensions, arrangements and parts with equivalent functionality) can be made to what has been described without departing from the scope of the invention as appears from the attached claims.

Nel metodo della presente invenzione, una massa permeabile o preforma comprendente almeno un tipo di rinforzo e polvere di alluminio o di lega di alluminio può essere infiltrata tramite alluminio o una lega di alluminio fusi in un ambiente protettivo senza l’applicazione di pressione aggiuntiva. I materiali di rinforzo comprendono ossidi (ossido di alluminio, ossido di silicio, ecc.), carburi (SiC, TiC, B4C ecc.), boruri (TiB2, AlB, MgB2ecc.), nitruri (AlN, TiN, Si3N4ecc.). Tale polvere di alluminio può essere identica al metallo della matrice oppure diversa dal metallo della matrice come composizione. E’ richiesta una quantità sufficiente di alluminio per una buona infiltrazione e la quantità dipende dalle proprietà del rinforzo, dalla polvere di alluminio e dalla preforma, ed anche dalla temperatura di infiltrazione, poiché la dimensione del rinforzo e della polvere di alluminio e la porosità della preforma hanno un’influenza evidente sull’infiltrazione. In generale, una temperatura superiore, una dimensione di rinforzo maggiore ed una porosità di preforma inferiore avranno un’influenza positiva sull’infiltrazione. Dopo un tempo di infiltrazione sufficiente, i compositi ottenuti possono essere estratti direttamente dal bagno di alluminio fuso ad una temperatura relativamente bassa di circa 680<o>C, e raffreddati all’aria, oppure potranno essere raffreddati insieme al bagno di alluminio fuso in un forno e quindi tagliati dai residui solidificati. In the method of the present invention, a permeable mass or preform comprising at least one type of reinforcement and aluminum or aluminum alloy powder can be infiltrated through aluminum or an aluminum alloy fused in a protective environment without the application of additional pressure. Reinforcement materials include oxides (aluminum oxide, silicon oxide, etc.), carbides (SiC, TiC, B4C etc.), borides (TiB2, AlB, MgB2 etc.), nitrides (AlN, TiN, Si3N4 etc.). Such aluminum powder can be identical to the metal of the matrix or different from the metal of the matrix in composition. A sufficient amount of aluminum is required for good infiltration and the amount depends on the properties of the reinforcement, the aluminum powder and the preform, as well as the infiltration temperature, since the size of the reinforcement and the aluminum powder and the porosity of the preforms have an obvious influence on infiltration. In general, a higher temperature, a larger reinforcement dimension and a lower preform porosity will have a positive influence on infiltration. After a sufficient infiltration time, the obtained composites can be extracted directly from the molten aluminum bath at a relatively low temperature of about 680 ° C, and air-cooled, or they can be cooled together with the molten aluminum bath in a oven and then cut from the solidified residues.

Riepilogando, il metodo inventivo per la fabbricazione di compositi a matrice di alluminio tramite infiltrazione senza pressione comprende le fasi di: In summary, the inventive method for fabricating aluminum matrix composites by pressureless infiltration includes the steps of:

- preparazione, come pre-bagnabilità, di una massa/preforma permeabile comprendente almeno un tipo di rinforzo e polvere di alluminio o lega di alluminio; e - preparation, as pre-wettability, of a permeable mass / preform comprising at least one type of reinforcement and aluminum or aluminum alloy powder; And

- messa in comunicazione di rinforzo e polvere di alluminio per generare un’infiltrazione spontanea di tale massa/preforma permeabile tramite alluminio o lega di alluminio fusa in un ambiente protettivo ad una temperatura di infiltrazione senza l’applicazione di una pressione aggiuntiva. - communication of reinforcement and aluminum powder to generate a spontaneous infiltration of this permeable mass / preform through molten aluminum or aluminum alloy in a protective environment at an infiltration temperature without applying additional pressure.

In particolare, si prevede che la fase di preparazione come pre-bagnabilità comprenda le sotto-fasi di: In particular, the preparation phase as pre-wettability is expected to include the sub-phases of:

- pesatura del rinforzo; - reinforcement weighing;

- pesatura della polvere di alluminio o lega di alluminio; - weighing of aluminum or aluminum alloy powder;

- miscelazione meccanica di rinforzo e polvere di alluminio o lega di alluminio; - mechanical mixing of reinforcement and aluminum or aluminum alloy powder;

- realizzazione della preforma al verde; e - creation of the green preform; And

- riscaldamento della preforma al verde in atmosfera protettiva. - heating of the green preform in a protective atmosphere.

Ancora in particolare, la fase di miscelazione meccanica viene effettuata alternativamente come: Still in particular, the mechanical mixing step is carried out alternatively as:

- miscelazione a secco, che genera polveri della miscela; o - dry mixing, which generates dust from the mixture; or

- miscelazione ad umido, che genera una miscela con solvente, sottoposta alternativamente ad essiccamento per ottenere polveri della miscela, oppure a pressatura o colata su nastro. - wet mixing, which generates a mixture with solvent, alternatively subjected to drying to obtain powders of the mixture, or to pressing or casting on a belt.

Inoltre, sono previste le fasi di: In addition, the phases of:

- fornitura di alluminio massivo; - supply of massive aluminum;

- immersione della preforma al verde nel bagno di alluminio; - immersion of the green preform in the aluminum bath;

- infiltrazione senza pressione ad una temperatura variabile tra 700 e 1500 °C; - infiltration without pressure at a variable temperature between 700 and 1500 ° C;

- formazione di un composito nel bagno di alluminio; - formation of a composite in the aluminum bath;

- estrazione del composito; - extraction of the composite;

- raffreddamento in aria o all'interno del bagno della matrice; ed - cooling in air or inside the matrix bath; and

- ottenimento del composito, oppure taglio del composito. - obtaining the composite, or cutting the composite.

La presente invenzione sarà ora descritta qui di seguito utilizzando alcuni esempi non limitativi del metodo per la fabbricazione di compositi a matrice di alluminio tramite infiltrazione senza pressione. The present invention will now be described below using some non-limiting examples of the method for manufacturing aluminum matrix composites by pressure-free infiltration.

Esempio 1 Example 1

In questo caso, polvere di ossido di alluminio di taglia 100 mesh e polvere di lega di alluminio 6061 di taglia -325 mesh sono state miscelate in una soluzione di etanolo, con un rapporto in peso di 6:8:10. Si è eseguita una macinazione a sfere a bassa velocità per 2 ore, quindi si è trasferita la sospensione in un becher pulito. Dopo un riposo di 30 minuti, si è estratto il precipitato e lo si è riscaldati ed agitato a 80 °C per 30 minuti, fino a quanto tutto l’etanolo rimasto è evaporato. In questo modo, si è preparata una miscela di ossido di alluminio e polveri di lega di alluminio 6061. Si è applicata una pressatura isostatica a freddo con una pressione tra 150 MPa e 200 MPa, e si è ottenuta una preforma con una porosità di circa il 20%. Si è preparato un rivestimento di polveri fini di ossido di alluminio in un crogiuolo refrattario (ossido di alluminio), e vi si è collocata all'interno la preforma e due masse di lega di alluminio 6061, con una delle masse sulla cima, ed un'altra sul fondo (Figura 1). Il crogiuolo è stato messo in un forno, ed il forno è stato ventilato con argo inerte per formare un'atmosfera protettiva. Il forno è stato riscaldato ad una velocità di 300-400 °C/h per 3-4 ore fino al raggiungimento di 1200 °C, mantenendo la temperatura per 2 ore. Dopo l'infiltrazione, il forno è stato raffreddato a temperatura ambiente, quindi si è interrotta l'applicazione di argo e si è estratto il crogiuolo, tagliando via infine i compositi derivati dai residui all'interno del crogiuolo. Si sono ottenuti compositi di Al2O3p/6061Al tramite infiltrazione senza pressione. Esempio 2 In this case, 100 mesh size aluminum oxide powder and -325 mesh size 6061 aluminum alloy powder were mixed in an ethanol solution, with a weight ratio of 6: 8: 10. Low speed ball grinding was performed for 2 hours, then the suspension was transferred to a clean beaker. After resting for 30 minutes, the precipitate was extracted and heated and stirred at 80 ° C for 30 minutes, until all the remaining ethanol has evaporated. In this way, a mixture of aluminum oxide and 6061 aluminum alloy powders was prepared. Cold isostatic pressing was applied with a pressure between 150 MPa and 200 MPa, and a preform with a porosity of about 20%. A coating of fine aluminum oxide powders was prepared in a refractory crucible (aluminum oxide), and placed inside the preform and two masses of 6061 aluminum alloy, with one of the masses on top, and a the other on the bottom (Figure 1). The crucible was placed in an oven, and the oven was ventilated with inert argon to form a protective atmosphere. The oven was heated at a rate of 300-400 ° C / h for 3-4 hours until reaching 1200 ° C, maintaining the temperature for 2 hours. After infiltration, the furnace was cooled to room temperature, then the argon application was stopped and the crucible removed, finally cutting off the composites derived from the residues inside the crucible. Composites of Al2O3p / 6061Al were obtained by infiltration without pressure. Example 2

In questo caso, si sono miscelate tramite agitazione, in una soluzione di butanolo, polvere di diboruro di titanio con dimensione di 2-10 micrometri e polvere di lega di alluminio 2024 di taglia -325 mesh a temperatura ambiente per 2 ore. Il rapporto in peso dei tre componenti (TiB2: 2024-Al: butanolo) era 1:1:2. Dopo agitazione, si è lasciata riposare la sospensione per 30 minuti fino a quando è avvenuta la sedimentazione. Si è rimosso lo strato superiore di liquido e si sono agitati i residui a 80 °C per altri 30 minuti, fino a quando si è rimosso tutto il liquido. Si sono sottoposte le polveri della miscela a pressatura isostatica a freddo per ottenere una preforma con una pressione di 150-200 MPa; la porosità della preforma era di circa il 25%-30%. Si sono disposte la preforma e le leghe di alluminio 2024 a matrice in crogiuoli refrattari come illustrato in Figura 2. Il crogiuolo è stato messo in un forno ed il forno è stato ventilato con gas azoto per formare un'atmosfera protettiva. Il forno è stato riscaldato alla temperatura di infiltrazione di 700 °C con un tasso di riscaldamento di 300-400 °C/h per circa 2 ore, mantenendo la temperatura a 700 °C per altre 2 ore per generare l'infiltrazione. Dopo l'infiltrazione, il forno è stato raffreddato a 680 °C in 30 minuti, e si è mantenuta la temperatura per altri 30 minuti. Quindi, si è interrotta l'applicazione di gas azoto, estraendo i compositi derivati e raffreddandoli in aria. Si sono ottenuti compositi TiB2p/2024 Al tramite infiltrazione senza pressione. In this case, titanium diboride powder with a size of 2-10 micrometers and 2024 aluminum alloy powder of size -325 mesh were mixed in a solution of butanol for 2 hours for 2 hours. The weight ratio of the three components (TiB2: 2024-Al: butanol) was 1: 1: 2. After stirring, the suspension was allowed to stand for 30 minutes until sedimentation took place. The top layer of liquid was removed and the residues stirred at 80 ° C for another 30 minutes, until all liquid was removed. The powders of the mixture were subjected to cold isostatic pressing to obtain a preform with a pressure of 150-200 MPa; the porosity of the preform was about 25% -30%. The preform and 2024 matrix aluminum alloys were placed in refractory crucibles as shown in Figure 2. The crucible was placed in an oven and the oven was vented with nitrogen gas to form a protective atmosphere. The oven was heated to the infiltration temperature of 700 ° C with a heating rate of 300-400 ° C / h for approximately 2 hours, maintaining the temperature at 700 ° C for a further 2 hours to generate the infiltration. After infiltration, the oven was cooled to 680 ° C in 30 minutes, and the temperature was maintained for another 30 minutes. Then, the application of nitrogen gas was stopped, extracting the derived composites and cooling them in air. TiB2p / 2024 Al composites were obtained by infiltration without pressure.

Esempio 3 Example 3

In questo caso, si sono miscelate con agitazione in una soluzione di etanolo polvere di carburo di titanio con dimensione di particelle di 2-10 micrometri e polvere di leghe di alluminio 7075 di taglia -325 mesh. Il loro rapporto in peso (TiC : 7075 : etanolo) era di 19:1:10; il processo di agitazione è durato 2 ore a temperatura ambiente per garantire una buona miscelazione della polvere di miscela. Si è lasciata riposare la sospensione per 30 minuti per avere la sedimentazione, quindi si è rimosso lo strato liquido superiore e si è continuato il processo di agitazione per altri 30 minuti a 80 °C per garantire la completa evaporazione di etanolo residuo. Dopo aver ottenuto una miscela di carburo di titanio e polvere di leghe di alluminio 7075 con una buona miscelazione, si è applicato un processo di pressatura isostatica a freddo per preparare la preforma. Con una pressione di 250 MPa - 300 MPa, la preforma ottenuta aveva una porosità pari a circa il 35%-40%. La preforma attaccata a metà delle due masse di leghe di alluminio 7075 è stata disposta all'interno di un crogiuolo refrattario e collocata in un forno ad alta temperatura. Si è utilizzata un'atmosfera sotto vuoto e un tasso di riscaldamento di 600 °C/h quando il grado di vuoto è risultato sotto a 0,01 pascal. Si è mantenuta la temperatura a 1100 °C per 2 ore, e si è poi raffreddato il forno a temperatura ambiente. Alla fine, si sono ottenuti compositi di TiCp/7075 Al tramite taglio del composito dall'alluminio solidificato del bagno di infiltrazione. In this case, titanium carbide powder with particle size of 2-10 micrometers and 7075 aluminum alloy powder of size -325 mesh were mixed with stirring in an ethanol solution. Their weight ratio (TiC: 7075: ethanol) was 19: 1: 10; the stirring process lasted 2 hours at room temperature to ensure a good mixing of the mixture powder. The suspension was allowed to stand for 30 minutes to have sedimentation, then the upper liquid layer was removed and the stirring process continued for another 30 minutes at 80 ° C to ensure complete evaporation of residual ethanol. After obtaining a mixture of titanium carbide and 7075 aluminum alloy powder with good mixing, a cold isostatic pressing process was applied to prepare the preform. With a pressure of 250 MPa - 300 MPa, the obtained preform had a porosity of about 35% -40%. The preform attached to the middle of the two masses of 7075 aluminum alloys was placed inside a refractory crucible and placed in a high-temperature furnace. A vacuum atmosphere and a heating rate of 600 ° C / h was used when the vacuum was below 0.01 pascal. The temperature was maintained at 1100 ° C for 2 hours, and the oven was then cooled to room temperature. Eventually, TiCp / 7075 Al composites were obtained by cutting the composite from the solidified aluminum of the infiltration bath.

Esempio 4 Example 4

Si sono miscelati con macinazione a sfere a bassa velocità, insieme a butanolo, per circa 2 ore, polvere di carburo di silicio UF10 e polvere di Al-Si10% di taglia -325 mesh con rapporto in peso pari a 5:1. Si è estratta la sospensione in un becher per la sedimentazione, lasciandola riposare per 30 minuti. Dopo aver rimosso lo strato di butanolo superiore, il sedimento della miscela è stato riscaldato ed agitato a 80 °C per altri 30 minuti per far evaporare il butanolo rimanente, fino a quanto la miscela è risultata completamente asciutta. Si è applicata pressatura isostatica alla polvere ben mescolata ad una pressione di 200 MPa -250 MPa a temperatura ambiente e la porosità della preforma ottenuta è stata di circa il 34%-38%. La preforma è stata posta a metà delle due masse di leghe di Al-10Si, disponendole all'interno di un crogiuolo refrattario e quindi riscaldandole a 1000 °C con un forno ad alta temperatura in un'atmosfera protettiva di argo. Il tasso di riscaldamento è stato di circa 300-400 °C/h e, dopo un mantenimento a 1000 °C per 2 ore, il forno è stato raffreddato a temperatura ambiente. I compositi derivati sono stati tagliati via dai residui solidificati e si è ottenuto SiCp/Al(Si). Low speed ball grinding, together with butanol, for about 2 hours, UF10 silicon carbide powder and 10% Al-Si powder of size -325 mesh with a weight ratio of 5: 1. The suspension was extracted into a beaker for sedimentation and left to stand for 30 minutes. After removing the top butanol layer, the mixture sediment was heated and stirred at 80 ° C for a further 30 minutes to evaporate the remaining butanol until the mixture was completely dry. Isostatic pressing was applied to the well mixed powder at a pressure of 200 MPa -250 MPa at room temperature and the porosity of the obtained preform was about 34% -38%. The preform was placed in the middle of the two masses of Al-10Si alloys, placing them inside a refractory crucible and then heating them to 1000 ° C with a high temperature oven in a protective argon atmosphere. The heating rate was about 300-400 ° C / h and, after holding at 1000 ° C for 2 hours, the oven was cooled to room temperature. The derived composites were cut away from the solidified residues and SiCp / Al (Si) was obtained.

Esempio 5 Example 5

In questo caso, polvere di silicio di taglia -325 mesh e polvere di alluminio di taglia -325 mesh con un rapporto in peso di 1:10 sono state aggiunte in un solvente di miscela di etanolo, butanolo ed olio di pesce. La sospensione è stata miscelata con un legante di polivinil butirrale (PVB) e polietilen glicole (PEG), tramite macinazione a sfere a bassa velocità per 12 ore. Si sono aggiunte gradualmente fibre tagliate di carburo di silicio di diametro 12 micrometri e lunghezza 10 mm, nell'impasto liquido già miscelato in una giara per macinazione a sfere. L'impasto liquido è stato agitato per altre 6 ore, quindi si sono rimosse le bolle di gas dall'impasto stesso, riducendo la pressione dell'aria. Si sono realizzati nastri su uno strumento di colata su nastro con l'impasto liquido finale. I nastri asciugati in aria sono stati dapprima bagnati con un solvente ottenuto dalla miscela di alcol polivinilico (PVA), etanolo e butanolo; quindi li si è impilati per formare una massa. Si è ottenuta la preforma sgrassando la massa in un forno ad una temperatura di 500 °C protetta da gas argo inerte. Due masse di leghe di Al-10Si sono state intercalate alla preforma preparata e disposte in un crogiuolo refrattario all'interno di un forno, protette da gas argo inerte. La temperatura del forno è stata innalzata ad un tasso di circa 300-400 °C/h per 2-3 ore, ed è stata tenuta a 900 °C per 2 ore fino al completamento dell'infiltrazione. Il forno è stato raffreddato a temperatura ambiente, si è separato l'alluminio connesso, e si sono ottenuti compositi di SiCsf/Al-10Si. In this case, silicon powder of size -325 mesh and aluminum powder of size -325 mesh with a weight ratio of 1:10 were added in a solvent of mixture of ethanol, butanol and fish oil. The suspension was mixed with a binder of polyvinyl butyral (PVB) and polyethylene glycol (PEG), by ball milling at low speed for 12 hours. Cut silicon carbide fibers with a diameter of 12 micrometers and a length of 10 mm were gradually added to the slurry already mixed in a ball-milling jar. The slurry was stirred for another 6 hours, then the gas bubbles were removed from the slurry, reducing the air pressure. Tapes were made on a tape casting tool with the final slurry. The air-dried tapes were first wetted with a solvent obtained from the mixture of polyvinyl alcohol (PVA), ethanol and butanol; then they were stacked to form a mass. The preform was obtained by degreasing the mass in an oven at a temperature of 500 ° C protected by inert argon gas. Two masses of Al-10Si alloys were interleaved with the prepared preform and placed in a refractory crucible inside an oven, protected by inert argon gas. The oven temperature was raised at a rate of about 300-400 ° C / h for 2-3 hours, and held at 900 ° C for 2 hours until the infiltration was completed. The furnace was cooled to room temperature, the connected aluminum separated, and SiCsf / Al-10Si composites were obtained.

Esempio 6 Example 6

In questo caso, si è utilizzato come rinforzo delle micro-fibre di carburo di silicio con dimensioni di 1,5 micrometri di diametro e circa 18 micrometri di lunghezza. Le micro-fibre di carburo di silicio sono state agitate con lega di alluminio Al-10Si di taglia -325 mesh per 2 ore per renderle molto ben miscelate; il loro rapporto in peso era di 10:1. Si è preparata la preforma dalla miscela tramite pressatura isostatica a freddo con una pressione di 200-250 MPa e la porosità della preforma è risultata intorno al 25%. La preforma è stata infiltrata in modo simile a quanto descritto nell'Esempio 5, tranne che la temperatura di infiltrazione è stata di 850 °C. Si è raffreddato il forno a temperatura ambiente, si sono estratti i residui dal crogiuolo, si è separato l'alluminio connesso, e si sono ottenuti compositi di SiCw/Al-10Si. In this case, silicon carbide micro-fibers with dimensions of 1.5 micrometers in diameter and about 18 micrometers in length were used as reinforcement. The silicon carbide micro-fibers were stirred with aluminum alloy Al-10Si of size -325 mesh for 2 hours to make them very well mixed; their weight ratio was 10: 1. The preform was prepared from the mixture by cold isostatic pressing with a pressure of 200-250 MPa and the porosity of the preform was found to be around 25%. The preform was infiltrated in a similar way to that described in Example 5, except that the infiltration temperature was 850 ° C. The furnace was cooled to room temperature, the residues were extracted from the crucible, the connected aluminum separated, and SiCw / Al-10Si composites were obtained.

Esempio 7 Example 7

Una polvere di nitruro di titanio della dimensione di 2-10 micrometri è stata miscelata on leghe di alluminio 2219 con un rapporto in peso di 3:2 tramite agitazione per 2 ore. Dopo essere stata miscelata a fondo, la miscela di polveri è stata pressata a freddo per formare una preforma tramite pressatura isostatica ad una pressione di 200-250 MPa, e la porosità della preforma è risultata intorno al 30-35%. La preforma è stata infiltrata in modo simile all'Esempio 2, tranne che la temperatura di infiltrazione è stata di 750 °C e le leghe della matrice erano una lega di alluminio 2219. Dopo l'infiltrazione, si è raffreddato il forno a 680 °C in 30 minuti, mantenendo la temperatura per altri 30 minuti. Quindi, si è interrotta l'applicazione del gas azoto, si sono raccolti i compositi derivati e li si è raffreddati in aria. Si sono ottenuti compositi di TiNp/2219 Al tramite infiltrazione senza pressione. A 2-10 micrometer size titanium nitride powder was mixed with 2219 aluminum alloys with a weight ratio of 3: 2 by stirring for 2 hours. After being thoroughly mixed, the powder mixture was cold pressed to form a preform by isostatic pressing at a pressure of 200-250 MPa, and the porosity of the preform was found to be around 30-35%. The preform was infiltrated similarly to Example 2 except that the infiltration temperature was 750 ° C and the matrix alloys were 2219 aluminum alloy. After infiltration, the oven was cooled to 680 ° C in 30 minutes, maintaining the temperature for another 30 minutes. Then, the nitrogen gas application was stopped, the derived composites were collected and cooled in air. TiNp / 2219 Al composites were obtained by pressure-free infiltration.

Sono state illustrate e descritte in precedenza alcune forme di realizzazione preferite della presente invenzione: ovviamente, agli esperti nel ramo risulteranno immediatamente evidenti numerose varianti e modifiche, funzionalmente equivalenti alle precedenti, che ricadono nel campo di protezione dell'invenzione come evidenziato nelle rivendicazioni allegate. Some preferred embodiments of the present invention have been illustrated and described above: obviously, numerous variants and modifications, functionally equivalent to the previous ones, which fall within the scope of the invention as highlighted in the attached claims, will be immediately apparent to those skilled in the art.

Claims (12)

RIVENDICAZIONI 1. Metodo per produrre compositi a matrice di alluminio tramite infiltrazione senza pressione, comprendente le fasi di: - preparazione, come pre-bagnabilità, di una massa/preforma permeabile comprendente almeno un tipo di rinforzo e polvere di alluminio o leghe di alluminio; e - messa in comunicazione di rinforzo e polvere di alluminio per generare un’infiltrazione spontanea di detta massa/preforma permeabile tramite alluminio o leghe di alluminio fusi in un ambiente protettivo ad una temperatura di infiltrazione senza pressione aggiuntiva. 2. Metodo secondo la rivendicazione 1, in cui detta massa/preforma permeabile è preparata tramite un processo di pressatura a freddo, pressatura a caldo, o colata su nastro, e la porosità di detta massa/preforma permeabile è inferiore all’80%. 3. Metodo secondo la rivendicazione 1 o 2, in cui detto rinforzo è di materiale ceramico. 4. Metodo secondo la rivendicazione 1 o 2, in cui detto rinforzo comprende polveri, micro-fibre, o fibre tagliate. 5. Metodo secondo la rivendicazione 3, in cui detteo materiale ceramico comprende ossidi, carburi, nitruri, o boruri. 6. Metodo secondo la rivendicazione 3, in cui detto materiale ceramico comprende ossido di silicio, ossido di alluminio, carburo di titanio, carburo di silicio, carburo di bodo, diboruro di titanio, boruro di alluminio, boruro di magnesio, nitruro di alluminio, nitruro di titanio, o nitruro di silicio. 7. Metodo secondo la rivendicazione 1, in cui detto ambiente protettivo comprende un'atmosfera di azoto, argo, o vuoto. 8. Metodo secondo la rivendicazione 1, in cui la fase di preparazione come pre-bagnabilità comprende le sotto-fasi di: - pesatura del rinforzo; - pesatura della polvere di alluminio o lega di alluminio; - miscelazione meccanica di rinforzo e polvere di alluminio o lega di alluminio; - realizzazione della preforma al verde; e - riscaldamento della preforma al verde in atmosfera protettiva. 9. Metodo secondo la rivendicazione 8, in cui la fase di miscelazione meccanica è eseguita in alternativa tramite: - miscelazione a secco, che genera polveri della miscela; o - miscelazione ad umido, che genera una miscela con solvente, sottoposta alternativamente ad essiccamento per ottenere polveri della miscela, oppure a pressatura o gettata a nastro. 10. Metodo secondo la rivendicazione 8 o 9, comprendente quindi le fasi di: - fornitura di alluminio massivo; - immersione della preforma al verde nel bagno di alluminio; - infiltrazione senza pressione ad una temperatura variabile tra 700 e 1500 °C; - formazione di un composito nel bagno di alluminio; - estrazione del composito; - raffreddamento in aria o all'interno del bagno di matrice; ed - ottenimento del composito, oppure taglio del composito. 11. Metodo secondo la rivendicazione 1, in cui la temperatura per detta infiltrazione spontanea è al di sopra di 650 °C. 12. Metodo secondo la rivendicazione 1, in cui detta massa/preforma permeabile contiene almeno l'1% in volume di materiali metallici. RIVENDICAZIONI 1. Method for producing aluminum matrix composites through pressure-less infiltration, comprising the steps of: - preparing, as pre-wettability, a permeable mass/preform comprising at least one type of reinforcement and aluminum or aluminum alloys powder; and - communicating reinforcement and aluminum powder to generate a spontaneous infiltration of said permeable mass/preform with molten aluminum or aluminum alloys in a protecting environment at an infiltration temperature without additional pressure. CLAIMS 1. Method for producing aluminum matrix composites by pressure-free infiltration, comprising the steps of: - preparation, as pre-wettability, of a permeable mass / preform comprising at least one type of reinforcement and aluminum powder or aluminum alloys; And - communication of reinforcement and aluminum powder to generate a spontaneous infiltration of said permeable mass / preform through aluminum or aluminum alloys fused in a protective environment at an infiltration temperature without additional pressure. 2. Method according to claim 1, wherein said permeable mass / preform is prepared by a process of cold pressing, hot pressing, or casting on tape, and the porosity of said permeable mass / preform is less than 80%. Method according to claim 1 or 2, wherein said reinforcement is of ceramic material. The method according to claim 1 or 2, wherein said reinforcement comprises powders, micro-fibers, or chopped fibers. 5. A method according to claim 3, wherein said ceramic material comprises oxides, carbides, nitrides, or borides. The method according to claim 3, wherein said ceramic material comprises silicon oxide, aluminum oxide, titanium carbide, silicon carbide, bodo carbide, titanium diboride, aluminum boride, magnesium boride, aluminum nitride, titanium nitride, or silicon nitride. 7. A method according to claim 1, wherein said protective environment comprises a nitrogen, argon, or vacuum atmosphere. Method according to claim 1, wherein the preparation step as pre-wettability comprises the sub-steps of: - reinforcement weighing; - weighing of aluminum or aluminum alloy powder; - mechanical mixing of reinforcement and aluminum or aluminum alloy powder; - creation of the green preform; And - heating of the green preform in a protective atmosphere. Method according to claim 8, wherein the mechanical mixing step is alternatively performed by: - dry mixing, which generates dust from the mixture; or - wet mixing, which generates a mixture with solvent, alternatively subjected to drying to obtain powders of the mixture, or by pressing or casting on a belt. 10. Method according to claim 8 or 9, thus comprising the steps of: - supply of massive aluminum; - immersion of the green preform in the aluminum bath; - infiltration without pressure at a variable temperature between 700 and 1500 ° C; - formation of a composite in the aluminum bath; - extraction of the composite; - cooling in air or inside the matrix bath; and - obtaining the composite, or cutting the composite. Method according to claim 1, wherein the temperature for said spontaneous infiltration is above 650 ° C. Method according to claim 1, wherein said permeable mass / preform contains at least 1% by volume of metallic materials. CLAIMS 1. Method for producing aluminum matrix composites through pressure-less infiltration, comprising the steps of: - preparing, as pre-wettability, a permeable mass / preform comprising at least one type of reinforcement and aluminum or aluminum alloys powder; and - communicating reinforcement and aluminum powder to generate a spontaneous infiltration of said permeable mass / preform with molten aluminum or aluminum alloys in a protecting environment at an infiltration temperature without additional pressure. 2. Method according to claim 1, wherein said permeable mass/preform is prepared by a process of cold pressing, hot pressing, tape casting, and the porosity of said permeable mass/preform is lower than 80%. 2. Method according to claim 1, wherein said permeable mass / preform is prepared by a process of cold pressing, hot pressing, tape casting, and the porosity of said permeable mass / preform is lower than 80%. 3. Method according to claim 1 or 2, wherein said reinforcement is of ceramic material. 3. Method according to claim 1 or 2, wherein said reinforcement is of ceramic material. 4. Method according to claim 1 or 2, wherein said reinforcement comprises powders, micro-fibres, chopped fibers. 4. Method according to claim 1 or 2, wherein said reinforcement comprises powders, micro-fibers, chopped fibers. 5. Method according to claim 3, wherein said ceramic material comprises oxides, carbides, nitrides, borides. 5. Method according to claim 3, wherein said ceramic material comprises oxides, carbides, nitrides, borides. 6. Method according to claim 3, wherein said ceramic material comprises silica, alumina, titanium carbide, silicon carbide, boron carbide, titanium diboride, aluminum boride, magnesium boride, aluminum nitride, titanium nitride, silicon nitride. 6. Method according to claim 3, wherein said ceramic material comprises silica, alumina, titanium carbide, silicon carbide, boron carbide, titanium diboride, aluminum boride, magnesium boride, aluminum nitride, titanium nitride, silicon nitride. 7. Method according to claim 1, wherein said protecting environment comprises nitrogen, argon, vacuum atmosphere. 7. Method according to claim 1, wherein said protecting environment comprises nitrogen, argon, vacuum atmosphere. 8. Method according to claim 1, wherein the step of preparing as pre-wettability comprises the substeps of: - weighing the reinforcement; - weighing the aluminum or aluminum alloys powder; - mechanically mixing reinforcement and aluminum or aluminum alloys powder; - making a green preform; and - heating the green preform in a protecting environment. 8. Method according to claim 1, wherein the step of preparing as pre-wettability comprises the substeps of: - weighing the reinforcement; - weighing the aluminum or aluminum alloys powder; - mechanically mixing reinforcement and aluminum or aluminum alloys powder; - making a green preform; and - heating the green preform in a protecting environment. 9. Method according to claim 8, wherein the step of mechanically mixing is alternatively performed through: - dry mixing, which generates mixture powders; or - humid mixing, which generates a mixture with solvent, alternatively subjected to drying to obtain mixture powders or to pressing or tape casting. 9. Method according to claim 8, wherein the step of mechanically mixing is alternatively performed through: - dry mixing, which generates mixture powders; or - humid mixing, which generates a mixture with solvent, alternatively subjected to drying to obtain mixture powders or to pressing or tape casting. 10. Method according to claim 8 or 9, comprising then the steps of: - providing massive aluminum; - immersing the green preform in an aluminum bath; - pressurelessly infiltrating at a temperature ranging between 700 and 1500 °C; - forming a composite in the aluminum bath; - extracting the composite and cooling(or cooling within the matrix bath); - obtaining the composite or cutting out the composite. 10. Method according to claim 8 or 9, comprising then the steps of: - providing massive aluminum; - immersing the green preform in an aluminum bath; - pressurelessly infiltrating at a temperature ranging between 700 and 1500 ° C; - forming a composite in the aluminum bath; - extracting the composite and cooling (or cooling within the matrix bath); - obtaining the composite or cutting out the composite. 11. Method according to claim 1, wherein the temperature for said spontaneous infiltration is above 650 °C. 11. Method according to claim 1, wherein the temperature for said spontaneous infiltration is above 650 ° C. 12. Method according to claim 1, wherein said permeable mass/preform contains at least 1% in volume of metallic materials.12. Method according to claim 1, wherein said permeable mass / preform contains at least 1% in volume of metallic materials.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0291441A1 (en) * 1987-05-13 1988-11-17 Lanxide Technology Company, Lp. Metal matrix composites
EP0368784A1 (en) * 1988-11-10 1990-05-16 Lanxide Technology Company, Lp. A method of forming a metal matrix composite body by a spontaneous infiltration technique
US5626914A (en) * 1992-09-17 1997-05-06 Coors Ceramics Company Ceramic-metal composites
US5676907A (en) * 1992-09-17 1997-10-14 Coors Ceramics Company Method for making near net shape ceramic-metal composites

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4600481A (en) 1982-12-30 1986-07-15 Eltech Systems Corporation Aluminum production cell components
US5287911A (en) * 1988-11-10 1994-02-22 Lanxide Technology Company, Lp Method for forming metal matrix composites having variable filler loadings and products produced thereby
US5020584A (en) * 1988-11-10 1991-06-04 Lanxide Technology Company, Lp Method for forming metal matrix composites having variable filler loadings and products produced thereby
US5509555A (en) 1994-06-03 1996-04-23 Massachusetts Institute Of Technology Method for producing an article by pressureless reactive infiltration
CN1345382A (en) 1999-12-21 2002-04-17 日立金属株式会社 Method for producing metal-based composite material

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0291441A1 (en) * 1987-05-13 1988-11-17 Lanxide Technology Company, Lp. Metal matrix composites
EP0368784A1 (en) * 1988-11-10 1990-05-16 Lanxide Technology Company, Lp. A method of forming a metal matrix composite body by a spontaneous infiltration technique
US5626914A (en) * 1992-09-17 1997-05-06 Coors Ceramics Company Ceramic-metal composites
US5676907A (en) * 1992-09-17 1997-10-14 Coors Ceramics Company Method for making near net shape ceramic-metal composites

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