Refractory metal plates

Patent metadata

Field	Value
Publication number	US-11443929-B2
Application number	US-202117155254-A
Country	US
Kind code	B2
Filing date	Jan 22, 2021
Priority date	Aug 6, 2007
Publication date	Sep 13, 2022
Grant date	Sep 13, 2022

Abstract

A refractory metal plate is provided. The plate has a center, a thickness, an edge, a top surface and a bottom surface, and has a crystallographic texture (as characterized by through thickness gradient, banding severity; and variation across the plate, for each of the texture components 100//ND and 111//ND, which is substantially uniform throughout the plate.

First claim

What is claimed is:

1. A method of forming a refractory metal plate, the method comprising:
(A) providing a workpiece having a size suitable for a target plate, the workpiece comprising a refractory metal;
(B) asymmetrically rolling the workpiece one or more times at an angle of incline between 2° and 20° relative to horizontal, thereby forming a rolled plate; and
(C) annealing the rolled plate to achieve substantially full recrystallization.

2. The method of claim 1 , wherein providing the workpiece comprises separating the workpiece from an ingot.

3. The method of claim 2 , wherein the ingot is an electron-beam-melted ingot.

4. The method of claim 1 , wherein providing the workpiece comprises separating the workpiece from a powder-metallurgy billet.

5. The method of claim 4 , further comprising providing the powder-metallurgy billet by a process comprising:
(a) cold isostatically pressing a refractory metal powder to a density of 60%-90% to form a preform;
(b) hot isostatically pressing the preform to a density of approximately 100% to form a billet; and
(c) annealing the billet.

6. The method of claim 1 , wherein the angle of incline is between 3° and 7°.

7. The method of claim 1 , wherein the workpiece is asymmetrically rolled a plurality of times during step (B).

8. The method of claim 7 , wherein the workpiece is rotated at a predetermined angle about a vertical axis between rolling passes.

9. The method of claim 7 , wherein the workpiece is flipped between rolling passes.

10. The method of claim 1 , further comprising, after step (C), bonding the plate to a backing plate.

11. The method of claim 1 , wherein after step (C):
the plate has a crystallographic texture as characterized by through thickness gradient, banding severity, and variation across the plate for at least one of the texture components 100//ND or 111//ND, using electron back-scatter diffraction with a 15 μm step in both the horizontal and vertical directions for each measurement;
an average through-thickness gradient is less than or equal to 6% per mm for 111//ND; and
a maximum through-thickness gradient is less than or equal to 13% per mm for 111//ND.

12. The method of claim 1 , wherein after step (C):
the plate has a crystallographic texture as characterized by through thickness gradient banding severity, and variation across the plate for at least one of the texture components 100//ND or 111//ND, using electron back-scatter diffraction with a 15 μm step in both the horizontal and vertical directions for each measurement; and an average banding severity is less than or equal to 6% per mm for 111//ND.

13. The method of claim 1 , wherein, after step (C):
the plate has a crystallographic texture as characterized by through thickness gradient, banding severity, and variation across the plate for at least one of the texture components 100//ND or 111//ND, using electron back-scatter diffraction with a 15 μm step in both the horizontal and vertical directions for each measurement; and a maximum banding severity is less than or equal to 8% per mm for 111//ND.

14. The method of claim 1 , further comprising, after step (C):
providing a substrate; and
sputtering the plate to form a film on the substrate, the film comprising the refractory metal.

15. The method of claim 1 , wherein the refractory metal comprises tantalum.

16. The method of claim 1 , further comprising annealing the workpiece before step (B).

17. The method of claim 1 , further comprising applying a lubricant to top and bottom surfaces of the workpiece before asymmetrically rolling the workpiece.

Assignees

• Starck H C Inc
• Materion Newton Inc

Inventors

• Jepson Peter R
• Bozkaya Dincer

Classifications

• B22F3/18

  by using pressure rollers · CPC title

• B21B2265/24

  asymmetric rolling · CPC title

• B21B1/22 Primary

  for rolling {plates, strips,} bands or sheets of indefinite length (B21B1/42 takes precedence) · CPC title

• B21B39/04

  Lifting or lowering work for conveying purposes, e.g. tilting tables arranged immediately in front of or behind the pass (turn-over or like manipulating means as such B21B39/20) · CPC title

• C22F1/18

  High-melting or refractory metals or alloys based thereon · CPC title