EP0415847B1 - X-ray tube rotating anticathode - Google Patents
X-ray tube rotating anticathode Download PDFInfo
- Publication number
- EP0415847B1 EP0415847B1 EP90402388A EP90402388A EP0415847B1 EP 0415847 B1 EP0415847 B1 EP 0415847B1 EP 90402388 A EP90402388 A EP 90402388A EP 90402388 A EP90402388 A EP 90402388A EP 0415847 B1 EP0415847 B1 EP 0415847B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- support
- anticathode
- matrix
- fibres
- sic
- 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
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J35/00—X-ray tubes
- H01J35/02—Details
- H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
- H01J35/08—Anodes; Anti cathodes
- H01J35/10—Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes
- H01J35/108—Substrates for and bonding of emissive target, e.g. composite structures
Definitions
- the invention relates to an X-ray tube anticathode designed so that it can rotate at very high speed.
- the anticathodes of X-ray tubes are rotating discs consisting of a support at least partially coated with an active layer of a refractory metal. They are used in medical devices such as scanners.
- the current trend of manufacturers of medical devices is to be able to increase the power received by the anticathode and / or to reduce the size of the impact spot of the electronic bombardment so as to improve the definition of the image obtained.
- This desire to increase the power or to decrease the size of the spot is limited by the slowness of the anticathode to dissipate the stored heat and, consequently, by the increase in the temperature of the focal track up to the melting temperature of the material constituting the active layer of the anti-cathode on which this track is formed.
- the support of the anticathode is made of a carbonaceous material consisting of a polycrystalline graphite whose expansion coefficient is compatible with that of the refractory metal such as tungsten, a tungsten-rhenium alloy or a molybdenum-based alloy. which is fixed (for example by brazing) or deposited (for example in the vapor phase or electrolytically) on this support.
- the refractory metal such as tungsten, a tungsten-rhenium alloy or a molybdenum-based alloy.
- the coefficient of expansion of a carbon-carbon composite is 0.5.10 ⁇ 6 ° K ⁇ 1 at 25 ° C and 2.106 ° K ⁇ 1 at 1000 ° C
- the coefficient of expansion of a metallic layer of tungsten-rhenium alloy is 4.10 ⁇ 6 ° K ⁇ 1 at 25 ° C and 4.5.10 ⁇ 6 ° K ⁇ 1 at 1000 ° C).
- An anticathode is thus produced having a mechanical resistance which allows it to rotate at very high speed, but the manufacture of the anti cathode is complicated by the incompatibility of the expansion coefficients of the carbon-carbon composite support on the one hand and of the graphite-metallic layer assembly on the other hand.
- the presence of a graphite substrate between the metallic layer and the composite support necessitates interposing between the graphite substrate and the metallic layer a very thin rhenium sublayer serving as an anti-carburizing barrier, as in conventional anodes. with graphite support.
- the temperature of use of the anticathode is thereby limited and its cost increased.
- the present invention specifically relates to an X-ray tube anticathode designed so that it can rotate at very high speed without the risk of bursting, while having a simpler and less costly structure than existing anticathodes and being able to be used for higher power densities or higher powers.
- a rotating X-ray tube anticathode comprising a support at least partially coated with an active layer of refractory metal, characterized in that the layer of refractory metal is in direct contact with the support, which is made of a composite material formed from ceramic fibers embedded in a ceramic matrix (ceramic / ceramic composite), this material having a coefficient of dilation adapted to that of the refractory metal.
- the speed of rotation of the anticathode can reach and even exceed 20,000 revolutions / min without the need for d 'Interpose between the support and the refractory metal an intermediate layer of graphite nor, therefore, an anti-carburizing undercoat.
- the anticathode can thus operate at much higher interface / active layer interface temperatures and therefore increase the performance of the X-ray tube.
- the removal of the intermediate graphite layer and the rhenium sublayer leads at an appreciable price gain.
- the support is made of a composite material chosen from a group comprising SiC fibers / SiC matrix; SiC fibers / Si3 N4 matrix; C fibers / SiC matrix; C fibers / B4C matrix; C fibers / Si3N4 matrix; SiC fibers / B4C matrix; and Ti B2 fibers / Ti B2 matrix.
- a material formed of SiC fibers embedded in an SiC matrix will preferably be chosen.
- the refractory metal is in known manner either tungsten or a tungsten-rhenium alloy.
- the ceramic / ceramic composite used in accordance with the invention to produce the Support for a rotating X-ray tube anticathode comprises a fiber reinforcement which can be formed either by a stack of two-dimensional fabrics, or by a three-dimensional fabric. From this reinforcement, the composite is obtained by impregnating the fibrous tissue in the liquid or gas phase with the material constituting the ceramic matrix of the composite.
- the density of the fibers in the composite material obtained is advantageously greater than 40% and the total porosity rate of this material is less than 20%.
- the coefficient of expansion of this composite is approximately 3 ⁇ 10 ⁇ 6 ° K ⁇ 1 to 25 ° C and 4 x 10 ⁇ 6 ° K ⁇ 1 at 1000 ° C.
- This coefficient of expansion should be compared to that of the tungsten-rhenium alloy, of which it is recalled that it is approximately 4 x 10 ⁇ 6 ° K ⁇ 1 at 25 ° C and 4.5 x 10 ⁇ 6 ° K ⁇ 1 at 1000 ° C.
- the metal active layer is placed in accordance with the invention directly in contact with the support of the anticathode.
- the connection between the metallic active layer and the support can be achieved in different ways.
- the metal layer can be made integral with the support of ceramic / ceramic material by brazing, deposited on this support by electrolysis by molten salt, by vapor deposition (CVD), by sputtering (PVD), by magnetron sputtering, by plasma projection, etc.
- the metal layer can also be secured to the support by recess or embedding, so that the two materials are nested and made mechanically integral.
- the support of the anticathode can also be made in other ceramic / ceramic composite materials which are chosen mainly so that their coefficient of expansion is as close as possible to the coefficient of expansion refractory metal with which this support is coated.
- examples of other composite materials that can thus be used to carry out the support of the anticathode are given in table II below:
- the problems of incompatibility of expansion coefficients previously encountered with the use of anticathode supports made of carbon / carbon composite material are thus resolved. This avoids crippling cracks that appear in the active metal layer of tungsten or tungsten-rhenium alloy when the latter is assembled directly on such a support. It also avoids having to interpose between this metal layer and the support any intermediate layer intended to solve the problems posed by the migration of carbon atoms in the metal layer.
Landscapes
- Ceramic Products (AREA)
- X-Ray Techniques (AREA)
- Physical Vapour Deposition (AREA)
- Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
- Materials For Medical Uses (AREA)
Abstract
Description
L'invention concerne une anticathode de tube à rayons X conçue de façon à pouvoir tourner à très grande vitesse.The invention relates to an X-ray tube anticathode designed so that it can rotate at very high speed.
Les anticathodes de tubes à rayons X sont des disques tournants constitués d'un support revêtu au moins partiellement d'une couche active en un métal réfractaire. Elles sont utilisées dans des appareils médicaux tels que les scanners.The anticathodes of X-ray tubes are rotating discs consisting of a support at least partially coated with an active layer of a refractory metal. They are used in medical devices such as scanners.
La tendance actuelle des constructeurs d'appareils médicaux est de pouvoir augmenter la puissance reçue par l'anticathode et/ou de réduire la taille du spot d'impact du bombardement électronique de manière à améliorer la définition de l'image obtenue. Ce désir d'augmenter la puissance ou de diminuer la taille du spot est limité par la lenteur de l'anticathode à évacuer la chaleur emmagasinée et, par voie de conséquence, par l'élévation de la température de la piste focale jusqu'à la température de fusion du matériau constituant la couche active de l'anti cathode sur laquelle est formée cette piste.The current trend of manufacturers of medical devices is to be able to increase the power received by the anticathode and / or to reduce the size of the impact spot of the electronic bombardment so as to improve the definition of the image obtained. This desire to increase the power or to decrease the size of the spot is limited by the slowness of the anticathode to dissipate the stored heat and, consequently, by the increase in the temperature of the focal track up to the melting temperature of the material constituting the active layer of the anti-cathode on which this track is formed.
Le plus souvent, le support de l'anticathode est réalisé en un matériau carboné constitué par un graphite polycristallin dont le coefficient de dilatation est compatible avec celui du métal réfractaire tel que du tungstène, un alliage tungstène-rhénium ou un alliage à base de molybdène qui est fixé (par exemple par brasure) ou déposé (par exemple en phase vapeur ou par voie électrolytique) sur ce support.Most often, the support of the anticathode is made of a carbonaceous material consisting of a polycrystalline graphite whose expansion coefficient is compatible with that of the refractory metal such as tungsten, a tungsten-rhenium alloy or a molybdenum-based alloy. which is fixed (for example by brazing) or deposited (for example in the vapor phase or electrolytically) on this support.
Afin de maintenir la température de la piste focale à des valeurs acceptables en régime permanent et/ou transitoire, tout en augmentant la puissance ou en diminuant la taille du spot, une solution consisterait à accroître sensiblement la vitesse de rotation des anticathodes, pour atteindre des vitesses par exemple égales ou supérieures à 20000 tours/mn. Malheureusement, les graphites polycristallins qui constituent habituellement le support des anticathodes ne présentent pas une résistance mécanique suffisante. En effet, ils éclatent sous l'effet de la force centrifuge avant d'atteindre une tel le vitesse.In order to maintain the temperature of the focal track at acceptable values under steady and / or transient conditions, while increasing the power or decreasing the size of the spot, one solution would consist in significantly increasing the speed of rotation of the anticathodes, in order to achieve for example equal speeds or higher than 20,000 rpm. Unfortunately, the polycrystalline graphites which usually constitute the support for anticathodes do not have sufficient mechanical strength. Indeed, they burst under the effect of centrifugal force before reaching such speed.
Par ailleurs, dans les anticathodes conventionnelles à support graphite revêtues d'une couche d'alliage tungstène-rhénium, il est nécessaire d'interposer une très fine sous-couche de rhénium. En effet, à partir de quelques centaines de degrés, les atomes de carbone du graphite ont tendance à migrer pour former avec le tungstène une couche fragile de carbure de tungstène provoquant une décohésion entre substrat et couche active et perturbant le transfert thermique. Le rhénium, jusqu'à une température d'environ 1200°C, empêche cette migration et joue donc le rôle de barrière anticarburation. Cependant, au-dessus de cette température, le rhénium est de moins en moins efficace et l'anticathode dépasse alors sa limite de fonctionnement. De plus, le rhénium est un produit cher qui contribue à augmenter le prix de l'anticathode.Furthermore, in conventional graphite-supported anticathodes coated with a layer of tungsten-rhenium alloy, it is necessary to interpose a very thin sublayer of rhenium. Indeed, from a few hundred degrees, the carbon atoms of graphite tend to migrate to form with tungsten a fragile layer of tungsten carbide causing decohesion between substrate and active layer and disrupting heat transfer. Rhenium, up to a temperature of around 1200 ° C, prevents this migration and therefore plays the role of anti-carburization barrier. However, above this temperature, the rhenium is less and less effective and the anticathode then exceeds its operating limit. In addition, rhenium is an expensive product which contributes to increasing the price of the anticathode.
D'autres matériaux moins onéreux tels que SiC, TaC pourraient jouer le rôle de barrière anticarburation. Mais l'addition d'une étape supplémentaire dans le procédé est toujours une cause de surcoût.Other less expensive materials such as SiC, TaC could play the role of anti-carburizing barrier. But the addition of an additional step in the process is always a cause of additional cost.
Dans le document EP-A-0 236 241, on a proposé de réaliser une anticathode à partir d'un support composite formé de fibres de carbone noyées dans une matrice de carbone (composite "carbone-carbone"). Un tel matériau composite présente une résistance mécanique beaucoup plus grande que les graphites polycristallins utilisés précédemment, ce qui permet de faire tourner l'anti cathode à très grande vitesse sans risque d 'éclatement du disque sous l'effet de la force centrifuge.In document EP-A-0 236 241, it has been proposed to produce an anticathode from a composite support formed of carbon fibers embedded in a carbon matrix ("carbon-carbon" composite). Such a composite material has a much greater mechanical resistance than the polycrystalline graphites used previously, which makes it possible to rotate the anti-cathode at very high speed without risk of bursting of the disc under the effect of centrifugal force.
Malheureusement, un tel matériau composite carbone-carbone a un coefficient de dilatation très différent de celui de la couche métallique. Ainsi, le coefficient de dilatation d'un composite carbone-carbone est de 0,5.10⁻⁶ °K⁻¹ à 25°C et de 2.10⁶ °K⁻¹ à 1000°C, alors que le coefficient de dilatation d'une couche métallique en alliage tungstène-rhénium est de 4.10⁻⁶ °K⁻¹ à 25°C et 4,5.10⁻⁶ °K⁻¹ à 1000°C).Unfortunately, such a composite material carbon-carbon has a coefficient of expansion very different from that of the metallic layer. Thus, the coefficient of expansion of a carbon-carbon composite is 0.5.10⁻⁶ ° K⁻¹ at 25 ° C and 2.10⁶ ° K⁻¹ at 1000 ° C, while the coefficient of expansion of a metallic layer of tungsten-rhenium alloy is 4.10⁻⁶ ° K⁻¹ at 25 ° C and 4.5.10⁻⁶ ° K⁻¹ at 1000 ° C).
Pour remédier à cet inconvénient, il est envisagé dans le document EP-A-0 236 241 de déposer la couche métallique sur un substrat en graphite de coefficient de di latation voisin de celui du métal, ce substrat en graphite étant associé d'une manière quelconque (brasure, collage, encastrement, etc.) au support composite carbone-carbone.To remedy this drawback, it is envisaged in document EP-A-0 236 241 to deposit the metal layer on a graphite substrate with a coefficient of dilation close to that of the metal, this graphite substrate being associated in a way any (brazing, bonding, embedding, etc.) to the carbon-carbon composite support.
On réalise ainsi une anticathode présentant une résistance mécanique qui lui permet de tourner à très grande vitesse, mais la fabrication de l'anti cathode se trouve compliquée par l' incompatibilité des coefficients de dilatation du support composite carbone-carbone d'une part et de l'ensemble graphite-couche métallique d'autre part. De plus, la présence d'un substrat en graphite entre la couche métallique et le support composite nécessite d'interposer entre le substrat en graphite et la couche métallique une très fine sous-couche de rhénium servant de barrière anticarburation, comme dans les anodes conventionnelles à support graphite. La température d'utilisation de l'anticathode s'en trouve limitée et son coût augmenté.An anticathode is thus produced having a mechanical resistance which allows it to rotate at very high speed, but the manufacture of the anti cathode is complicated by the incompatibility of the expansion coefficients of the carbon-carbon composite support on the one hand and of the graphite-metallic layer assembly on the other hand. In addition, the presence of a graphite substrate between the metallic layer and the composite support necessitates interposing between the graphite substrate and the metallic layer a very thin rhenium sublayer serving as an anti-carburizing barrier, as in conventional anodes. with graphite support. The temperature of use of the anticathode is thereby limited and its cost increased.
La présente invention a précisément pour objet une anticathode de tube à rayons X conçue de façon à pouvoir tourner à très grande vitesse sans risque d'éclatement, tout en présentant une structure plus simple et moins coûteuse que les anticathodes existantes et en pouvant être utilisée à des densités de puissance ou des puissances plus élevées.The present invention specifically relates to an X-ray tube anticathode designed so that it can rotate at very high speed without the risk of bursting, while having a simpler and less costly structure than existing anticathodes and being able to be used for higher power densities or higher powers.
Selon l'invention, ce résultat est obtenu au moyen d'une anticathode tournante de tube à rayons X, comprenant un support revêtu au moins partiellement d'une couche active de métal réfractaire, caractérisée par le fait que la couche de métal réfractaire est en contact direct avec le support, qui est réalisé en un matériau composite formé de fibres céramiques noyées dans une matrice céramique (composite céramique/céramique), ce matériau ayant un coefficient de di latation adapté à celui du métal réfractaire.According to the invention, this result is obtained at by means of a rotating X-ray tube anticathode, comprising a support at least partially coated with an active layer of refractory metal, characterized in that the layer of refractory metal is in direct contact with the support, which is made of a composite material formed from ceramic fibers embedded in a ceramic matrix (ceramic / ceramic composite), this material having a coefficient of dilation adapted to that of the refractory metal.
On comprend aisément qu'en utilisant un matériau composite céramique/céramique dont le coefficient de dilatation est compatible avec celui du métal réfractaire, la vitesse de rotation de l'anticathode peut atteindre et même dépasser 20000 tours/mn sans qu'il soit nécessaire d' interposer entre le support et le métal réfractaire une couche intermédiaire de graphite ni, par conséquent, une sous-couche anti carburation. L'anticathode peut ainsi fonctionner à des températures d'interface support/couche active beaucoup plus élevées et donc accroître les performances du tube à rayons X. De plus, la suppression de la couche intermédiaire de graphite et de la sous-couche de rhénium conduit à un gain de prix appréciable.It is easily understood that by using a ceramic / ceramic composite material whose coefficient of expansion is compatible with that of the refractory metal, the speed of rotation of the anticathode can reach and even exceed 20,000 revolutions / min without the need for d 'Interpose between the support and the refractory metal an intermediate layer of graphite nor, therefore, an anti-carburizing undercoat. The anticathode can thus operate at much higher interface / active layer interface temperatures and therefore increase the performance of the X-ray tube. In addition, the removal of the intermediate graphite layer and the rhenium sublayer leads at an appreciable price gain.
Avantageusement, le support est réalisé en un matériau composite choisi dans un groupe comprenant fibres de SiC/matrice de SiC ; fibres de SiC/matrice de Si₃ N₄ ; fibres de C/matrice de SiC ; fibres de C/matrice de B₄C ; fibres de C/matrice de Si₃N₄ ; fibres de SiC/matrice de B₄C ; et fibres de Ti B₂/matrice de Ti B₂.Advantageously, the support is made of a composite material chosen from a group comprising SiC fibers / SiC matrix; SiC fibers / Si₃ N₄ matrix; C fibers / SiC matrix; C fibers / B₄C matrix; C fibers / Si₃N₄ matrix; SiC fibers / B₄C matrix; and Ti B₂ fibers / Ti B₂ matrix.
Parmi ces matériaux composites, on choisira de préférence un matériau formé de fibres de SiC noyées dans une matrice de SiC.Among these composite materials, a material formed of SiC fibers embedded in an SiC matrix will preferably be chosen.
Avantageusement, le métal réfractaire est de façon connue, soit du tungstène, soit un alliage tungstène-rhénium.Advantageously, the refractory metal is in known manner either tungsten or a tungsten-rhenium alloy.
Dans la pratique, le composite céramique/céramique utilisé conformément à l'invention pour réaliser le support d'une anticathode tournante de tube à rayons X comprend une armature de fibres qui peut être formée soit par un empilement de tissus bidimensionnels, soit par un tissu tridimensionnel. A partir de cette armature, le composite est obtenu par imprégnation en phase liquide ou gazeuse des tissus fibreux par le matériau constituant la matrice céramique du composite. La densité des fibres, dans le matériau composite obtenu, est avantageusement supérieure à 40 % et le taux de porosité totale de ce matériau est inférieur à 20 %.In practice, the ceramic / ceramic composite used in accordance with the invention to produce the Support for a rotating X-ray tube anticathode comprises a fiber reinforcement which can be formed either by a stack of two-dimensional fabrics, or by a three-dimensional fabric. From this reinforcement, the composite is obtained by impregnating the fibrous tissue in the liquid or gas phase with the material constituting the ceramic matrix of the composite. The density of the fibers in the composite material obtained is advantageously greater than 40% and the total porosity rate of this material is less than 20%.
Dans le cas où le matériau composite céramique/céramique est constitué de fibres de carbure de silicium noyées dans une mat ri ce de carbure de silicium, le coefficient de dilatation de ce composite est d'environ 3 x 10⁻⁶ °K⁻¹ à 25°C et 4 x 10⁻⁶ °K⁻¹ à 1000°C. Ce coefficient de dilatation est à rapprocher de ce lui de l'alliage tungstène-rhénium dont il est rappelé qu'il est d'environ 4 x 10⁻⁶ °K⁻¹ à 25°C et 4,5 x 10⁻⁶ °K⁻¹ à 1000°C.In the case where the ceramic / ceramic composite material consists of silicon carbide fibers embedded in a material of silicon carbide, the coefficient of expansion of this composite is approximately 3 × 10⁻⁶ ° K⁻¹ to 25 ° C and 4 x 10⁻⁶ ° K⁻¹ at 1000 ° C. This coefficient of expansion should be compared to that of the tungsten-rhenium alloy, of which it is recalled that it is approximately 4 x 10⁻⁶ ° K⁻¹ at 25 ° C and 4.5 x 10⁻⁶ ° K⁻¹ at 1000 ° C.
Compte tenu du fait que ces coefficients de dilatation du support composite et de l'alliage métallique sont adaptés, la couche active métallique est placée conformément à l'invention directement au contact du support de l'anticathode.Given the fact that these expansion coefficients of the composite support and of the metal alloy are suitable, the metal active layer is placed in accordance with the invention directly in contact with the support of the anticathode.
La liaison entre la couche active métallique et le support peut être réalisée de différentes manières. Ainsi, la couche métallique peut être rendue solidaire du support en matériau céramique/céramique par brasure, déposée sur ce support par électrolyse par sel fondu, par dépôt en phase vapeur (CVD), par pulvérisation cathodique (PVD), par pulvérisation magnétron, par projection-plasma, etc.. La couche métallique peut aussi être solidarisée au support par embrèvement ou encastrement, de telle sorte que les deux matériaux soient imbriqués et rendus mécaniquement solidaires.The connection between the metallic active layer and the support can be achieved in different ways. Thus, the metal layer can be made integral with the support of ceramic / ceramic material by brazing, deposited on this support by electrolysis by molten salt, by vapor deposition (CVD), by sputtering (PVD), by magnetron sputtering, by plasma projection, etc. The metal layer can also be secured to the support by recess or embedding, so that the two materials are nested and made mechanically integral.
A titre d'exemple, on pourra choisir pour la réalisation du support de l'anticathode des composites SiC/SiC ayant les caractéristiques données dans le tableau I suivant :
Comme on a déjà eu l 'occasion de le mentionner, le support de l'anticathode peut aussi être réalisé dans d'autres matériaux composites céramique/céramique qui sont choisis principalement afin que leur coefficient de dilatation soit aussi proche que possible du coefficient de dilatation du métal réfractaire dont ce support est revêtu. Des exemples d'autres matériaux composites qui peuvent ainsi être utilisés pour réaliser le support de l'anticathode sont donnés dans le tableau II ci-dessous :
Conformément à l'invention, on règle ainsi les problèmes d' incompatibilité de coefficients de dilatation rencontrés précédemment avec l 'utilisation de supports d'anticathodes en matériau composite carbone/carbone. On évite ainsi les fissures rédhibitoires qui apparaissent dans la couche métallique active en tungstène ou en alliage tungstène-rhénium lorsque cette dernière est assemblée directement sur un tel support. On évite aussi d'avoir à interposer entre cette couche métallique et le support une couche intermédiaire quelconque destinée à résoudre les problèmes posés par la migration des atomes de carbons dans la couche métallique.According to the invention, the problems of incompatibility of expansion coefficients previously encountered with the use of anticathode supports made of carbon / carbon composite material are thus resolved. This avoids crippling cracks that appear in the active metal layer of tungsten or tungsten-rhenium alloy when the latter is assembled directly on such a support. It also avoids having to interpose between this metal layer and the support any intermediate layer intended to solve the problems posed by the migration of carbon atoms in the metal layer.
Il devient ainsi possible de faire tourner l'anticathode à une vitesse très grande qui peut atteindre ou même dépasser 20000 tours/mn, tout en en simplifiant la fabrication et en en réduisant le coût.It thus becomes possible to rotate the anticathode at a very high speed which can reach or even exceed 20,000 rpm, while simplifying the manufacture and reducing the cost.
Des modélisations thermiques ont ainsi montré qu'à diamètre équivalent, des anticathodes réalisées conformément à 'invention peuvent recevoir des puissances bien supérieures à celles acceptables pour des anticathodes à support en graphite selon la technique couramment utilisée.Thermal modeling has thus shown that, for an equivalent diameter, anticathodes produced in accordance with the invention can receive powers much higher than those acceptable for anticathodes with graphite support according to the technique commonly used.
Claims (5)
- Rotating X-ray tube anticathode including a support coated with at least partly an active refractory metal film, characterized in that the active refractory metal film is in direct contact with the support made of a composite material formed of ceramic fibres embedded in a ceramic matrix, this material having a coefficient of expansion close to that of the refractory metal.
- Anticathode according to claim 1, characterized in that the support is made of a composite material selected from the group including: Sic fibres/Sic matrix; Sic fibres/Si₃N₄ matrix; C fibres/SiC matrix; C fibres /B₄C matrix; C fibres/Si₃N₄ matrix; Sic fibres/B₄C matrix; and TiB₂ fibres/TiB₂ matrix.
- Anticathode according to claim 2, characterized in that the support is made of a composite material formed of SiC fibres embedded in a SiC matrix.
- Anticathode according to any one of the claims 1 to 3, characterized in that the refractory metal is selected from the group including tungsten and rhenium/tungsten alloys.
- Anticathode according to any one of the claims 1 to 4, characterized in that the composite material includes woven fibres, the density of the fibres in the material being greater than 40% and the total porosity of the material being less than 20%.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8911441 | 1989-08-31 | ||
| FR8911441A FR2651370B1 (en) | 1989-08-31 | 1989-08-31 | ROTATING ANTICATHODE OF X-RAY TUBE. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0415847A1 EP0415847A1 (en) | 1991-03-06 |
| EP0415847B1 true EP0415847B1 (en) | 1994-12-07 |
Family
ID=9385037
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP90402388A Expired - Lifetime EP0415847B1 (en) | 1989-08-31 | 1990-08-29 | X-ray tube rotating anticathode |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US5031201A (en) |
| EP (1) | EP0415847B1 (en) |
| AT (1) | ATE115333T1 (en) |
| DE (1) | DE69014779D1 (en) |
| FR (1) | FR2651370B1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL9000061A (en) * | 1990-01-10 | 1991-08-01 | Philips Nv | ROTARY TURNAROOD. |
| DE19626094C2 (en) * | 1996-05-02 | 2000-10-19 | Siemens Ag | Anode body for an X-ray tube |
| JP3143086B2 (en) * | 1997-10-14 | 2001-03-07 | 核燃料サイクル開発機構 | SiC composite sleeve and method of manufacturing the same |
| DE10021716B4 (en) * | 2000-05-04 | 2005-01-05 | Siemens Ag | Rotary piston tube |
| US20070207338A1 (en) * | 2006-03-01 | 2007-09-06 | Plasma Processes, Inc. | X-ray target and method for manufacturing same |
| DE102011083064B4 (en) * | 2011-09-20 | 2013-06-13 | Siemens Aktiengesellschaft | Rotary anode and method for producing a base body for a rotary anode |
| WO2015142762A1 (en) | 2014-03-17 | 2015-09-24 | Brown Roy A | Surgical targeting systems and methods |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3314881A1 (en) * | 1983-04-25 | 1984-10-25 | Siemens AG, 1000 Berlin und 8000 München | X-ray tube anode |
| JPS6012653A (en) * | 1983-07-01 | 1985-01-23 | Hitachi Ltd | X-ray tube target |
| JPH0719533B2 (en) * | 1984-06-22 | 1995-03-06 | 株式会社日立製作所 | Method of manufacturing rotating target for X-ray tube |
| JPS643947A (en) * | 1987-06-25 | 1989-01-09 | Hitachi Ltd | Rotary anode target for x-ray tube |
| JPS6454648A (en) * | 1987-08-26 | 1989-03-02 | Hitachi Ltd | Rotating anode target for x-ray tube |
| FR2625606B1 (en) * | 1987-12-30 | 1995-05-19 | Thomson Cgr | METHOD FOR MANUFACTURING A ROTATING ANODE FOR X-RAY TUBE, AND ROTATING ANODE OBTAINED ACCORDING TO THIS METHOD |
-
1989
- 1989-08-31 FR FR8911441A patent/FR2651370B1/en not_active Expired - Fee Related
-
1990
- 1990-08-24 US US07/572,718 patent/US5031201A/en not_active Expired - Fee Related
- 1990-08-29 EP EP90402388A patent/EP0415847B1/en not_active Expired - Lifetime
- 1990-08-29 AT AT90402388T patent/ATE115333T1/en not_active IP Right Cessation
- 1990-08-29 DE DE69014779T patent/DE69014779D1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US5031201A (en) | 1991-07-09 |
| ATE115333T1 (en) | 1994-12-15 |
| EP0415847A1 (en) | 1991-03-06 |
| DE69014779D1 (en) | 1995-01-19 |
| FR2651370B1 (en) | 1991-12-06 |
| FR2651370A1 (en) | 1991-03-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3040132B2 (en) | Composite composed of graphite and refractory metal | |
| EP0415847B1 (en) | X-ray tube rotating anticathode | |
| JPH04223032A (en) | X-ray tube target | |
| WO2010070574A1 (en) | Attachment of a high-z focal track layer to a carbon-carbon composite substrate serving as a rotary anode target | |
| JPH0793117B2 (en) | Anode of X-ray tube having diffusion barrier layer in focal track region | |
| US5204891A (en) | Focal track structures for X-ray anodes and method of preparation thereof | |
| EP0236241B1 (en) | Support for rotating the anti-cathode of an x-ray tube | |
| FR2625035A1 (en) | ROTATING ANODE OF COMPOSITE MATERIAL FOR X-RAY TUBE | |
| WO1999045564A1 (en) | X-ray tube rotating anode | |
| FR2467483A1 (en) | RONTGEN TUBE WITH A ROTATING ANODE WHOSE BASE BODY IS IN GRAPHITE AND METHOD OF MANUFACTURING ANODE FOR SUCH A TUBE | |
| FR2625605A1 (en) | ROTATING ANODE FOR X-RAY TUBE | |
| JPS63211547A (en) | X ray tube target | |
| US6301333B1 (en) | Process for coating amorphous carbon coating on to an x-ray target | |
| JP4498477B2 (en) | Carbon composite material for reducing atmosphere furnace and method for producing the same | |
| EP0660400B1 (en) | Thermoconductive element, usable in electronics as a support of a printed circuit or a component and its method of fabrication | |
| FR2655191A1 (en) | ANODE FOR X-RAY TUBE. | |
| EP0323366A1 (en) | Manufacturing method of a rotating anode of an X-ray tube | |
| US5099506A (en) | X-ray rotary anode | |
| EP2591489B1 (en) | X-ray emitting anode and process for manufacturing such an anode | |
| EP0185598B1 (en) | Rotary anode for an x-ray tube | |
| EP1200973B1 (en) | Improved oxide-coated cathode and method for making same | |
| FR2593325A1 (en) | Graphite rotating anode for X-ray tube | |
| EP0430768A1 (en) | Composite base anode for X-ray tube | |
| EP0430767A1 (en) | X-ray tube anode of high mechanical resistance | |
| FR2692829A1 (en) | Fabrication of a component from a composite material - with an intermetallic matrix possessing a low temperature eutectic or peritectic reaction |
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): AT DE ES GB IT NL |
|
| 17P | Request for examination filed |
Effective date: 19910809 |
|
| 17Q | First examination report despatched |
Effective date: 19940208 |
|
| GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
| AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT DE ES GB IT NL |
|
| 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 FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;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.SCRIBED TIME-LIMIT Effective date: 19941207 Ref country code: ES Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY Effective date: 19941207 Ref country code: AT Effective date: 19941207 Ref country code: GB Effective date: 19941207 Ref country code: NL Effective date: 19941207 |
|
| REF | Corresponds to: |
Ref document number: 115333 Country of ref document: AT Date of ref document: 19941215 Kind code of ref document: T |
|
| RAP2 | Party data changed (patent owner data changed or rights of a patent transferred) |
Owner name: COMURHEX SOCIETE POUR LA CONVERSION DE L'URANIUM E |
|
| REF | Corresponds to: |
Ref document number: 69014779 Country of ref document: DE Date of ref document: 19950119 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19950308 |
|
| NLV1 | Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act | ||
| GBV | Gb: ep patent (uk) treated as always having been void in accordance with gb section 77(7)/1977 [no translation filed] |
Effective date: 19941207 |
|
| 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 |
|
| 26N | No opposition filed |