EP0185598B1 - Rotary anode for an x-ray tube - Google Patents
Rotary anode for an x-ray tube Download PDFInfo
- Publication number
- EP0185598B1 EP0185598B1 EP85420225A EP85420225A EP0185598B1 EP 0185598 B1 EP0185598 B1 EP 0185598B1 EP 85420225 A EP85420225 A EP 85420225A EP 85420225 A EP85420225 A EP 85420225A EP 0185598 B1 EP0185598 B1 EP 0185598B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- emissive material
- base body
- anode according
- anode
- ray tube
- 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
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 present invention relates to an anode, in particular a rotating anode intended to equip an X-ray tube.
- X-ray tubes used mainly in radiology are equipped with disc-shaped amodes or anticathodes whose function is to emit X-radiation from the parts of their surface which are subjected to the action of a flow of electrons coming from a cathode with a sufficiently high kinetic energy.
- this basic body had to have, at the same time, a high melting temperature, a high specific heat and a good coefficient of thermal conductivity.
- molybdenum we turned to graphite because it had a much higher specific heat and also because it was lighter, which simplified its rotation in the case of anodes rotating.
- problems with cracking of the active zone due, both to reactions which occur between the tungsten layer and the graphite and which lead to fragile intermediate layers and to differences in expansion between the materials present.
- it has been recommended to deposit a barrier layer between graphite and tungsten which can be, for example, pure rhenium as taught in French patent 1,575,117.
- This product is a nitrogenous aluminum compound, with the chemical formula AIN which can be obtained in powder form and whose thermal and mechanical properties allow it to be shaped by conventional sintering techniques to give a solid of density 3 , 26 approximately, that is to say a little larger than graphite but, clearly smaller than that of molybdenum.
- This product also has a relatively high melting temperature and in particular a good coefficient of thermal conductivity which makes it possible to channel and evacuate throughout the anode the significant thermal flux created in the active area.
- the Applicant has found perfect adhesion between the elements of the composite thus formed, a quality which is maintained over time. under the action of electron fluxes of very high kinetic energy.
- the anode according to the invention finds its application in all X-ray tubes including the most recent models implementing high powers and rotational speeds which can be greater than 10,000 revolutions / minute.
Landscapes
- X-Ray Techniques (AREA)
- Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
- Ceramic Products (AREA)
- Electrolytic Production Of Metals (AREA)
Abstract
Description
La présente invention a pour objet une anode, notamment une anode tournante destinée à équiper un tube à rayons X.The present invention relates to an anode, in particular a rotating anode intended to equip an X-ray tube.
L'homme de l'art sait que les tubes à rayons X utilisés principalement en radiologie sont équipés d'amodes ou anticathodes en forme de disque dont la fonction est d'émettre un rayonnement X à partir des parties de leur surface qui sont soumises à l'action d'un flux d'électrons provenant d'une cathode avec une énergie cinétique suffisamment grande.Those skilled in the art know that X-ray tubes used mainly in radiology are equipped with disc-shaped amodes or anticathodes whose function is to emit X-radiation from the parts of their surface which are subjected to the action of a flow of electrons coming from a cathode with a sufficiently high kinetic energy.
Il est également connu que dans un tube à rayons X l'énergie cinétique des électrons n'est transformée en énergie de rayons X que dans une proportion voisine de 1 %, de sorte que la majeure partie de l'énergie des électrons se convertit en chaleur.It is also known that in an X-ray tube the kinetic energy of the electrons is only transformed into X-ray energy in a proportion close to 1%, so that most of the energy of the electrons is converted into heat.
C'est pourquoi, à l'origine, ces anodes étaient constituées exclusivement par un matériau ayant, outre de bonnes caractéristiques d'émissivité de rayons X, une temperature de fusion très élevée, tel que, par exemple, le tungstène et ses alliages avec le rhénium notamment. Par la suite, les techniciens s'étant inquiétés du prix de revient élevé et du poids de ces anodes, se sont aperçus qu'il suffisait de fabriquer avec le tungstène seulement les parties qui recevaient les électrons, c'est-à-dire les "zones actives" ou les "pistes focales" de l'anode. On s'est alors orienté vers des anodes composites formées d'un corps de base en un produit mieux adapté que le tungstène, ledit corps étant muni de zones actives obtenues par revêtement de tungstène ou de ses alliages.This is why, at the origin, these anodes consisted exclusively of a material having, in addition to good characteristics of emissivity of X-rays, a very high melting temperature, such as, for example, tungsten and its alloys with rhenium in particular. Thereafter, the technicians having worried about the high cost price and the weight of these anodes, realized that it was enough to manufacture with tungsten only the parts which received the electrons, that is to say the "active zones" or the "focal tracks" of the anode. We then turned to composite anodes formed from a basic body in a product better suited than tungsten, said body being provided with active zones obtained by coating tungsten or its alloys.
Pour assurer sa fonction correctement, ce corps de base devait avoir, à la fois, une température de fusion élevée, une grande chaleur spécifique et un bon coefficient de conductibilité thermique. On a d'abord utilisé le molybdène puis on s'est tourné vers le graphite parce qu'il avait une chaleur spécifique beaucoup plus élevée et aussi parce qu'il était plus léger, ce qui simplifiait sa mise en rotation dans le cas des anodes tournantes. Mais on s'est alors heurté à des problèmes de fissuration de la zone active dûs, à la fois à des réactions qui se produisent entre la couche de tungstène et le graphite et qui conduisent à des couches intermédiaires fragiles et à des différences de dilatation entre les matériaux en présence. Pour remédier à ce défaut on a préconisé de déposer une couche barrière entre le graphite et le tungstène qui peut être, par exemple, du rhénium pur comme cela est enseigné dans le brevet français 1 575 117. De plus, le développement de la radiologie a conduit les concepteurs de matériel à étudier l'accroissement de la vitesse de rotation de l'anode et à rechercher des vitesses pouvant dépasser largement 10.000 tours/minute. A ces vitesses, les qualités mécaniques du corps de base doivent être élevées et ce corps doit posséder une faible densité, une chaleur spécifique élevée et un bon coefficient de conductibilité thermique.To ensure its proper function, this basic body had to have, at the same time, a high melting temperature, a high specific heat and a good coefficient of thermal conductivity. We first used molybdenum then we turned to graphite because it had a much higher specific heat and also because it was lighter, which simplified its rotation in the case of anodes rotating. But we then encountered problems with cracking of the active zone due, both to reactions which occur between the tungsten layer and the graphite and which lead to fragile intermediate layers and to differences in expansion between the materials present. To remedy this defect, it has been recommended to deposit a barrier layer between graphite and tungsten which can be, for example, pure rhenium as taught in French patent 1,575,117. In addition, the development of radiology has leads the designers of equipment to study the increase in the speed of rotation of the anode and to seek speeds which can greatly exceed 10,000 revolutions / minute. At these speeds, the mechanical qualities of the basic body must be high and this body must have a low density, high specific heat and a good coefficient of thermal conductivity.
Consciente des avantages que procuraient les anodes composites dont le corps de base est moins dense que le molybdène, la demanderesse a cherché à trouver un matériau répondant à ces critères et qui, à la différence du graphite, ne nécessite pas la présence d'une couche barrière et permet par ses caractéristiques mécaniques élevées d'atteindre des vitesses de rotation pouvant dépasser 10.000 tours/minute.Aware of the advantages of composite anodes whose base body is less dense than molybdenum, the applicant sought to find a material which meets these criteria and which, unlike graphite, does not require the presence of a layer barrier and allows by its high mechanical characteristics to reach rotation speeds that can exceed 10,000 revolutions / minute.
Ses recherches ont abouti à la mise au point d'une anode caractérisée en ce que le corps de base est constitué par du nitrure d'aluminium.His research led to the development of an anode characterized in that the basic body is made of aluminum nitride.
Ce produit est un composé azoté de l'aluminium, de formule chimique AIN qui peut être obtenu à l'état de poudre et dont les propriétés thermiques et mécaniques permettent la mise en forme par les techniques classiques de frittage pour donner un solide de densité 3,26 environ, c'est-à-dire un peu plus grande que le graphite mais, nettement plus petite que celle du molybdène. Ce produit possède également une température de fusion relativement élevée et notamment un bon coefficient de conductibilité thermique qui permet de canaliser et d'évacuer dans toute l'anode le flux thermique important créé dans la zone active. Ce sont là autant de caractéristiques qui en font un produit intéressant pour la confection des anodes mais qui ne suffiraient pas à être compétitif vis-à-vis du graphite ou des anodes en métal massif, s'il n'avait pas été découvert par la demanderesse, que ledit produit pouvait être revêtu directement par le matériau émissif sans avoir besoin de prévoir une couche d'accrochage ou une couche barrière et si ledit produit ne présentait pas les caractéristiques mécaniques permettant son utilisation à des vitesses de rotation élevées.This product is a nitrogenous aluminum compound, with the chemical formula AIN which can be obtained in powder form and whose thermal and mechanical properties allow it to be shaped by conventional sintering techniques to give a solid of density 3 , 26 approximately, that is to say a little larger than graphite but, clearly smaller than that of molybdenum. This product also has a relatively high melting temperature and in particular a good coefficient of thermal conductivity which makes it possible to channel and evacuate throughout the anode the significant thermal flux created in the active area. These are all characteristics which make it an interesting product for the manufacture of anodes but which would not be sufficient to be competitive vis-à-vis graphite or anodes in solid metal, if it had not been discovered by the Applicant, that said product could be coated directly with the emissive material without the need to provide a bonding layer or a barrier layer and if said product did not have the mechanical characteristics allowing its use at high rotational speeds.
En effet quelle que soit la nature du métal ou alliage constituant la zone active et la manière de le déposer sur le corps de base, la demanderesse a constaté une adhérence parfaite entre les éléments du composite ainsi constitué, qualité qui se maintient dans le temps même sous l'action de flux d'électrons de très grande énergie cinétique.Indeed, whatever the nature of the metal or alloy constituting the active area and the manner of depositing it on the base body, the Applicant has found perfect adhesion between the elements of the composite thus formed, a quality which is maintained over time. under the action of electron fluxes of very high kinetic energy.
C'est ainsi qu'ont été réalisés des dépôts d'épaisseur comprise entre 0,5 et 2 mm de tungstène, de rhénium, d'iridium, d'osmium et de leurs alliages ou de leurs composés du type carbure, nitrure, borure suivant des procédés très différents tels que l'électrolyse en bain de sel fondu, le dépôt en phase vapeur qu'il soit physique ou chimique, la fixation par brasage ou autre méthode de fixation d'éléments en métal fritté, sous forme de couronne, de portions de couronne, sur des surfaces planes ou en creux sans qu'on observe de phénomènes de décohésion ou d'altérations après de longues périodes d'utilisation dans des tubes de grande puissance mis en oeuvre dans les techniques radiologiques les plus modernes.This is how deposits with a thickness of between 0.5 and 2 mm were made of tungsten, rhenium, iridium, osmium and their alloys or their compounds of the carbide, nitride, boride type. according to very different processes such as electrolysis in a molten salt bath, vapor deposition, whether physical or chemical, fixing by brazing or other method of fixing elements made of sintered metal, in the form of a crown, crown portions, on flat or recessed surfaces without any observed phenomena of decohesion or deterioration after long periods of use in high-power tubes used in the most modern radiological techniques.
A titre d'exemple, on peut citer le cas d'une anode classique qui était utilisée dans des conditions de puissance et de temps telles que la température de la zone active était comprise entre 2500 et 300°C et que l'on a remplacé par une anode selon l'invention.By way of example, one can cite the case of a conventional anode which was used under power and time conditions such as the temperature of the active area was between 2500 and 300 ° C and that was replaced by an anode according to the invention.
Son emploi dans les mêmes conditions a conduit à un abaissement de la temperature de la zone active comprise entre 200 et 400° C ce qui montre les bonnes caractéristiques de transmission de chaleur du nitrure d'aluminium.Its use under the same conditions has led to a lowering of the temperature of the active zone of between 200 and 400 ° C. which shows the good heat transmission characteristics of aluminum nitride.
L'anode selon l'invention trouve son application dans tous les tubes à rayons X y compris les modèles les plus récents mettant en oeuvre des puissances élevées et des vitesses de rotation pouvant être supérieures à 10.000 tours/minute.The anode according to the invention finds its application in all X-ray tubes including the most recent models implementing high powers and rotational speeds which can be greater than 10,000 revolutions / minute.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT85420225T ATE39784T1 (en) | 1984-12-13 | 1985-12-10 | ROTATING ANODE FOR X-RAY TUBE. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8419398A FR2574988B1 (en) | 1984-12-13 | 1984-12-13 | ROTATING ANODE FOR X-RAY TUBE |
| FR8419398 | 1984-12-13 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0185598A1 EP0185598A1 (en) | 1986-06-25 |
| EP0185598B1 true EP0185598B1 (en) | 1989-01-04 |
Family
ID=9310746
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP85420225A Expired EP0185598B1 (en) | 1984-12-13 | 1985-12-10 | Rotary anode for an x-ray tube |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0185598B1 (en) |
| JP (1) | JPS61143929A (en) |
| AT (1) | ATE39784T1 (en) |
| DE (1) | DE3567318D1 (en) |
| FR (1) | FR2574988B1 (en) |
| SU (1) | SU1479013A3 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4975621A (en) * | 1989-06-26 | 1990-12-04 | Union Carbide Corporation | Coated article with improved thermal emissivity |
| JPH0793099B2 (en) * | 1990-07-27 | 1995-10-09 | 信淳 渡辺 | Method for manufacturing rotating anode X-ray tube target |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1178523B (en) * | 1962-07-04 | 1964-09-24 | Patra Patent Treuhand | X-ray tube rotating anode, in particular a plate-shaped rotating anode |
| US3459678A (en) * | 1966-01-03 | 1969-08-05 | Eastman Kodak Co | Olefin hydration catalyst |
| DE2201979C3 (en) * | 1972-01-17 | 1979-05-03 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Process for the production of a blackened layer on rotating anodes of X-ray tubes |
| US3819971A (en) * | 1972-03-22 | 1974-06-25 | Ultramet | Improved composite anode for rotating-anode x-ray tubes thereof |
| AT336143B (en) * | 1975-03-19 | 1977-04-25 | Plansee Metallwerk | X-ray anode |
| CA1142211A (en) * | 1978-11-20 | 1983-03-01 | Richard G. Weber | Rotatable x-ray target having off-focal track coating |
| JPS56141153A (en) * | 1980-04-03 | 1981-11-04 | Toshiba Corp | Target for x-ray tube |
-
1984
- 1984-12-13 FR FR8419398A patent/FR2574988B1/en not_active Expired
-
1985
- 1985-12-10 EP EP85420225A patent/EP0185598B1/en not_active Expired
- 1985-12-10 DE DE8585420225T patent/DE3567318D1/en not_active Expired
- 1985-12-10 AT AT85420225T patent/ATE39784T1/en not_active IP Right Cessation
- 1985-12-11 SU SU853985468A patent/SU1479013A3/en active
- 1985-12-11 JP JP60278846A patent/JPS61143929A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| FR2574988B1 (en) | 1988-04-29 |
| JPH023263B2 (en) | 1990-01-23 |
| SU1479013A3 (en) | 1989-05-07 |
| EP0185598A1 (en) | 1986-06-25 |
| DE3567318D1 (en) | 1989-02-09 |
| JPS61143929A (en) | 1986-07-01 |
| ATE39784T1 (en) | 1989-01-15 |
| FR2574988A1 (en) | 1986-06-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4090103A (en) | X-ray target | |
| US5008918A (en) | Bonding materials and process for anode target in an x-ray tube | |
| CA2196589C (en) | Titanium nitride doped with boron, substrate coating based on this new compound, with good hardness conferring very good resistance to wear, and parts bearing such a coating | |
| US5148463A (en) | Adherent focal track structures for X-ray target anodes having diffusion barrier film therein and method of preparation thereof | |
| EP0273161B1 (en) | X-ray tube target | |
| EP1060497A1 (en) | X-ray tube rotating anode | |
| US4978051A (en) | X-ray tube target | |
| JPH05217532A (en) | Focus tracking strucutre of anode of x-ray tube and its manufacture | |
| EP0185598B1 (en) | Rotary anode for an x-ray tube | |
| NL8104258A (en) | IMPROVED PLATE FOR ROENTGEN TUBES. | |
| US5352489A (en) | Method for manufacturing a rotary anode for X-ray tube | |
| FR2655191A1 (en) | ANODE FOR X-RAY TUBE. | |
| US5099506A (en) | X-ray rotary anode | |
| JPH0598423A (en) | Chrome coating film for preventing oxidation of titanium | |
| JPH01209626A (en) | Method of manufacturing rotary anode for x-ray tube and rotary anode obtained by the method | |
| US20070207338A1 (en) | X-ray target and method for manufacturing same | |
| JPS598252A (en) | Rotary target for x-ray tube and its production method | |
| EP0112206B1 (en) | Method of coating metallic surfaces with carbides | |
| JPH0719533B2 (en) | Method of manufacturing rotating target for X-ray tube | |
| FR2593325A1 (en) | Graphite rotating anode for X-ray tube | |
| JPH07251293A (en) | Method for hard facing by welding onto aluminum alloy surface | |
| JPH0480493B2 (en) | ||
| JP2004197116A (en) | Hearth liner for electron beam deposition | |
| JPH02288136A (en) | X-ray tube target and manufacture of same and x-ray tube | |
| JPH03122955A (en) | Rotary anode target for x-ray tube |
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 BE DE GB IT |
|
| 17P | Request for examination filed |
Effective date: 19860730 |
|
| 17Q | First examination report despatched |
Effective date: 19880330 |
|
| GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
| AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE DE GB IT |
|
| REF | Corresponds to: |
Ref document number: 39784 Country of ref document: AT Date of ref document: 19890115 Kind code of ref document: T |
|
| ITF | It: translation for a ep patent filed |
Owner name: ING. A. GIAMBROCONO & C. S.R.L. |
|
| REF | Corresponds to: |
Ref document number: 3567318 Country of ref document: DE Date of ref document: 19890209 |
|
| GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) | ||
| 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 | ||
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19931115 Year of fee payment: 9 Ref country code: DE Payment date: 19931115 Year of fee payment: 9 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: AT Payment date: 19931117 Year of fee payment: 9 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 19931206 Year of fee payment: 9 |
|
| ITTA | It: last paid annual fee | ||
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19941210 Ref country code: AT Effective date: 19941210 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Effective date: 19941231 |
|
| BERE | Be: lapsed |
Owner name: COMURHEX SOC. POUR LA CONVERSION DE L'URANIUM EN Effective date: 19941231 |
|
| GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19941210 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19950901 |