X-ray diffraction method

• US 7,844,028 B2
• Filed: 01/24/2003
• Issued: 11/30/2010
• Est. Priority Date: 01/25/2002
• Status: Expired due to Fees

• Current Assignee: Isis Innovation Limited
• Original Assignee: Isis Innovation Limited
• Inventors: Korsunsky, Alexander M.
• Primary Examiner(s): Glick; Edward J
• Assistant Examiner(s): Midkiff; Anastasia
• Application Number:
  US10/502,432
• Publication Number:
  US 20060176998A1
• Time in Patent Office: 2,867 Days
• Field of Search: 378 70- 78, 378/84, 378/85
• US Class Current: 378/73
• CPC Class Codes: G01N 23/20 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials

Abstract

An X-ray diffraction method for the analysis of polycrystalline materials, the method comprising: (a) providing a polycrystalline material for analysis; (b) providing a polychromatic X-ray source, wherein the source produces X-rays by accelerating charged particles to energies of no more than 1 MeV; (c) collimating X-rays from the polychromatic X-ray source into a beam having a divergence in the range of from 10⁻⁴ to 10⁻² radians; (d) exposing at least a portion of the polycrystalline material to the collimated X-ray beam, whereby the beam is diffracted; (e) collecting at least some of the diffracted X-rays in an energy dispersive X-ray detector or array; and (f) analysing the collected, diffracted X-rays.

Claims

1. An X-ray diffraction method for the analysis of polycrystalline materials, the method comprising:

(a) providing a polycrystalline material for analysis;

(b) providing a polychromatic X-ray source, wherein the source produces X-rays by accelerating charged particles to energies of no more than 1 MeV;

(c) collimating X-rays from the polychromatic X-ray source into a beam having a divergence in the range of from 10<sup>−

4</sup> to 10<sup>−

2</sup> radians;

(d) exposing at least a portion of the polycrystalline material to the collimated X-ray beam, whereby the beam is diffracted;

(e) collecting at least some of the diffracted X-rays in an energy dispersive X-ray detector or array; and

(f) analyzing the collected, diffracted x-rays;

(g) quantitatively mapping a lattice parameter in the polycrystalline material using said analyzed, collected, diffracted x-rays.

2. A method as claimed in claim 1, wherein the source produces X-rays by accelerating charged particles to energies of no more than 500 keV.

3. A method as claimed in claim 1, wherein the energy dispersive X-ray detector has a relative energy resolution of from 0.5×

10<sup>−

2</sup> to 5×

10<sup>−

2</sup>.

4. A method as claimed in claim 1, wherein the energy of the collimated X-ray beam is ≧

60 keV.

5. A method as claimed in claim 1, wherein the collimated X-ray beam penetrates the polycrystalline material to an attenuation depth of ≧

1 mm.

6. A method as claimed in claim 1, further comprising moving the collimated X-ray beam relative to the polycrystalline material.

7. A method as claimed in claim 6, comprising scanning the collimated X-ray beam across at least a portion of the polycrystalline material, while keeping the polycrystalline material stationary.

8. A method as claimed in claim 1, wherein the collected, diffracted X-rays are analysed in order to determine a structural and/or chemical characteristic of the polycrystalline material.

9. A method as claimed in claim 8, wherein the structural characteristic is the lattice parameter.

10. A method as claimed in claim 9, wherein lattice parameter determination is used to provide information on phase distributions, stresses and/or strains in the polycrystalline material.

11. A method as claimed in claim 10, wherein lattice parameter determination is used to map phase distributions, stresses and/or strains in the polycrystalline material.

12. A method as claimed in claim 11, wherein lattice parameter determination is used to map phase distributions, stresses and/or strains in the polycrystalline material at a depth of ≧

1 mm.

13. A method as claimed in claim 1, wherein the polycrystalline material is an engineering article or component part thereof.

14. A method as claimed in claim 1, wherein the polycrystalline material comprises a metal or alloy, ceramic or crystalline polymer, including combinations of two or more thereof.

15. A method as claimed in claim 1, wherein the polycrystalline material is a composite material comprising a crystalline phase.

16. A method as claimed in claim 15, wherein the metal matrix composite material is a glass and/or ceramic reinforced metal matrix composite material.

17. A method as claimed in claim 1, wherein said portion of the polycrystalline material has a thickness of ≧

1 mm.

24. A method as claimed in claim 4, wherein the energy of the collimated X-ray beam has a range of from 100 to 300 KeV.

18. An apparatus for X-ray diffraction analysis of polycrystalline materials, the apparatus comprising:

(i) a polychromatic X-ray source, wherein the source produces X-rays by accelerating charged particles to energies of no more than 1 MeV;

(ii) means for collimating X-rays from the polychromatic X-ray source into a beam having a divergence in the range of from 10<sup>−

4</sup> to 10<sup>−

2</sup> radians;

(iii) an energy dispersive X-ray detector or array for collecting at least some of the diffracted X-rays resulting, in use, from exposing at least a portion of a polycrystalline material to the collimated X-ray beam; and

(iv) means for analyzing the collected, diffracted x-rays;

(v) means for quantitatively mapping a lattice parameter in the polycrystalline material using said analyzed, collected, diffracted x-rays.

19. An apparatus as claimed in claim 18, wherein the polychromatic source is moveable with respect to a polycrystalline material to be analysed.

20. An apparatus as claimed in claim 18, wherein the collimated X-ray beam is adapted, in use, to scan, across the polycrystalline material, while the polycrystalline material is maintained stationary.

21. A method of quantitatively mapping the sub-surface distribution of the crystal lattice parameter in a polycrystalline material, the method comprising:

(a) providing a sample for analysis, wherein the sample comprises a polycrystalline material;

(b) providing a polychromatic X-ray source, wherein the source produces X-rays by accelerating charged particles to energies of no more than 1 MeV;

(c) collimating X-rays from the polychromatic X-ray source into a beam having a divergence in the range of from 10<sup>−

4</sup> to 10<sup>−

2</sup> radians, and a penetration depth of ≧

1 mm

(d) scanning the collimated X-ray beam across the sample, whereby the beam is diffracted;

(e) collecting at least some of the diffracted X-rays in an energy dispersive X-ray detector or array; and

(f) analysing the collected, diffracted X-rays to map the lattice parameter in the polycrystalline material.

22. A method as claimed in claim 21, wherein the polycrystalline material is a natural material or an engineering material, including a component formed therefrom.

23. A method as claimed in claim 21, further including:

(g) transforming the map of the lattice parameter into a map of sub-surface engineering stresses and/or strains.