Rotary X-ray anode

Patent metadata

Field	Value
Publication number	US-9368318-B2
Application number	US-201213980585-A
Country	US
Kind code	B2
Filing date	Jan 17, 2012
Priority date	Jan 19, 2011
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A rotary X-ray anode has a support body and a focal track formed on the support body. The support body and the focal track are produced as a composite by powder metallurgy. The support body is formed from molybdenum or a molybdenum-based alloy and the focal track is formed from tungsten or a tungsten-based alloy. Here, in the conclusively heat-treated rotary X-ray anode, at least one portion of the focal track is located in a non-recrystallized and/or in a partially recrystallized structure.

First claim

The invention claimed is:

1. A rotary X-ray anode, comprising:
a powder-metallurgically produced composite formed of a support body and a focal track on said support body;
said support body being formed of molybdenum or a molybdenum-based alloy;
said focal track being formed of tungsten or a tungsten-based alloy; and
wherein, in a conclusively heat-treated rotary X-ray anode, at least one portion of said focal track is present in a non-recrystallized or a partially recrystallized structure;
wherein the at least one portion of said focal track has a mean small-angle grain boundary spacing of ≦10 μm;
wherein the mean small-angle grain boundary spacing can be determined by a measurement process in which grain boundaries, grain boundary portions and small-angle grain boundaries with a grain boundary angle of ≧5° are determined on a radial cross-sectional area running perpendicular to said focal track plane in a region of the at least one portion of the focal track;
to determine the mean small-angle grain boundary spacing parallel to the focal track plane, a group of lines which runs parallel to the cross-sectional area and is made up of lines each running parallel to the focal track plane and at a spacing of in each case 17.2 μm in relation to one another is placed into the grain boundary pattern thereby obtained, respectively the spacings between in each case two mutually adjacent intersections between the respective line and lines of the grain boundary pattern are determined on the individual lines, and the mean value of these spacings is determined as the mean small-angle grain boundary spacing parallel to the focal track plane;
to determine the mean small-angle grain boundary spacing perpendicular to the focal track plane, a group of lines which runs parallel to the cross-sectional area and is made up of lines each running perpendicular to the focal track plane and at a spacing of in each case 17.2 μm in relation to one another is placed into the grain boundary pattern obtained, respectively the spacings between in each case two mutually adjacent intersections between the respective line and lines of the grain boundary pattern are determined on the individual lines, and the mean value of these spacings is determined as the mean small-angle grain boundary spacing perpendicular to the focal track plane; and
the mean small-angle grain boundary spacing is determined as a geometric mean value of the mean small-angle grain boundary spacing parallel to the focal track plane and of the mean small-angle grain boundary spacing perpendicular to the focal track plane.

2. The rotary X-ray anode according to claim 1 , wherein said at least one portion of said focal track has, in a direction perpendicular to a focal track plane, a preferential texturing in a <111> direction with a texture coefficient TC (222) of ≧4 determinable by way of X-ray diffraction and a preferential texturing in a <001> direction with a texture coefficient TC (200) of ≧5 determinable by way of X-ray diffraction.

3. The rotary X-ray anode according to claim 1 , wherein the following relationship for the texture coefficients TC (222) and TC (310) determinable by way of X-ray diffraction is satisfied for the portion of the focal track perpendicular to the focal track plane:
TC (222) /TC (310) ≧5.

4. The rotary X-ray anode according to claim 1 , wherein the at least one portion of said focal track has a hardness of ≧350 HV 30.

5. The rotary X-ray anode according to claim 1 , wherein the at least one portion of said focal track is present in a partially recrystallized structure.

6. The rotary X-ray anode according to claim 5 , wherein:
crystal grains formed in the partially recrystallized structure by new grain formation are surrounded by a deformation structure; and
in terms of a cross-sectional area through the partially recrystallized structure, the crystal grains have an areal proportion in a range of 10% to 80%.

7. The rotary X-ray anode according to claim 1 , wherein said at least one portion of said focal track has a preferential texturing in a <101> direction in directions parallel to a plane of said focal track plane.

8. The rotary X-ray anode according to claim 1 , wherein at least one portion of said support body is present in a non-recrystallized or partially recrystallized structure.

9. The rotary X-ray anode according to claim 8 , wherein the at least one portion of said support body has a hardness of ≧230 HV 10.

10. The rotary X-ray anode according to claim 8 , wherein:
said at least one portion of said support body has a preferential texturing in a <111> direction and in a <001> direction perpendicular to the focal track plane; and/or said at least one portion of said support body has a preferential texturing in the <101> direction in directions parallel to said focal track plane.

11. The rotary X-ray anode according to claim 8 , wherein said at least one portion of said support body has an elongation at break of ≧2.5% at room temperature.

12. The rotary X-ray anode according to claim 1 , wherein said support body is formed of a molybdenum-based alloy, having further alloying constituents including at least one alloying constituent selected from the group consisting of Ti, Zr and Hf, and at least one alloying constituent selected from the group consisting of C and N.

13. A method of generating X-ray radiation which comprises providing a rotary X-ray anode according to claim 1 in an X-ray tube and generating the X-ray radiation therewith.

14. A method of producing a rotary X-ray anode, the method which comprises:
providing a starting body produced as a composite by pressing and sintering corresponding starting powders, the starting body having a support body portion made of molybdenum or a molybdenum-based mixture and a focal track portion, formed on the support body portion, made of tungsten or a tungsten-based mixture;
forging the starting body; and
subjecting the body to a heat treatment during the forging step, after the forging step, or during and after the forging step, to form a rotary X-ray anode according to claim 1 ;
adjusting a temperature of the heat treatment and a processing time of the heat treatment such that, in the finally and conclusively heat-treated rotary X-ray anode, at least one portion of the focal track obtained from the focal track portion is present in a non-recrystallized and/or in a partially recrystallized structure.

15. The method according to claim 14 , which comprises carrying out the heat treatment at temperatures in a range of 1300° C.-1500° C.

16. The method according to claim 14 , wherein the forged body has a degree of deformation in a range of 20% to 60% after completion of the forging step.

Assignees

• Eiter Johann
• Schatte Jürgen
• Glatz Wolfgang
• Knabl Wolfram
• Leichtfried Gerhard
• SCHÖNAUER Stefan
• Plansee Se

Inventors

• Eiter Johann
• Schatte Jürgen
• Glatz Wolfgang
• Knabl Wolfram
• Leichtfried Gerhard
• SCHÖNAUER Stefan

Classifications

• H01J35/108 Primary

  Substrates for and bonding of emissive target, e.g. composite structures · CPC title

• H01J2235/081

  Target material · CPC title

• H01J2235/085

  Target treatment, e.g. ageing, heating · CPC title

• H01J35/101

  Arrangements for rotating anodes, e.g. supporting means, means for greasing, means for sealing the axle or means for shielding or protecting the driving · CPC title