Stable nanocrystalline ordering alloy systems and methods of identifying same

Patent metadata

Field	Value
Publication number	US-9791394-B2
Application number	US-201414282691-A
Country	US
Kind code	B2
Filing date	May 20, 2014
Priority date	May 21, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

Provided in one embodiment is a method of identifying a stable phase of an ordering binary alloy system comprising a solute element and a solvent element, the method comprising: determining at least three thermodynamic parameters associated with grain boundary segregation, phase separation, and intermetallic compound formation of the ordering binary alloy system; and identifying the stable phase of the ordering binary alloy system based on the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter by comparing the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter with a predetermined set of respective thermodynamic parameters to identify the stable phase; wherein the stable phase is one of a stable nanocrystalline phase, a metastable nanocrystalline phase, and a non-nanocrystalline phase.

First claim

What is claimed:

1. A method of identifying a stable phase of an alloy system comprising a solute element and a solvent element, the method comprising:
(A) determining at least a first thermodynamic parameter associated with grain boundary segregation of the alloy system, a second thermodynamic parameter associated with phase separation of the alloy system, and a third thermodynamic parameter associated with intermetallic compound formation of the alloy system; and
(B) identifying the stable phase of the alloy system based on the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter by comparing the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter with a predetermined set of respective thermodynamic parameters to identify the stable phase;
wherein:
the stable phase is one of a stable nanocrystalline phase, a metastable nanocrystalline phase, and a non-nanocrystalline phase,
the alloy system is one in which an intermetallic compound may be formed, and
the alloy system has a negative enthalpy of mixing.

2. The method of claim 1 , wherein (A) further comprises determining at least one of the at least three thermodynamic parameters with an assumption that the alloy system is a non-dilute alloy system.

3. The method of claim 1 , further comprising making the stable phase of the alloy system.

4. The method of claim 1 , wherein (B) further comprises identifying boundary parameters that delineate the stable phase as a function of the at least three thermodynamic parameters.

5. The method of claim 1 , further comprising:
determining at least a first thermodynamic parameter associated with grain boundary segregation of a different alloy system, a second thermodynamic parameter associated with phase separation of the different alloy system, and a third thermodynamic parameter associated with intermetallic compound formation of the different alloy system; and
identifying a stable phase of the different alloy system by, at least, comparing the first thermodynamic parameter of the different alloy system, the second thermodynamic parameter of the different alloy system, and the third thermodynamic parameter of the different alloy system with a predetermined set of respective thermodynamic parameters to identify the stable phase of the different alloy system;
wherein the stable phase of the different alloy system is one of a stable nanocrystalline phase of the different alloy system, a metastable nanocrystalline phase of the different alloy system, and a non-nanocrystalline phase of the different alloy system.

6. The method of claim 1 , wherein in (A) the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter are determined at a predetermined temperature.

7. The method of claim 1 , wherein in (A) the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter are determined at a temperature of about 1000 K.

8. The method of claim 1 , wherein in the case where the stable phase is the stable nanocrystalline phase, the method further comprises identifying the stable phase of the alloy system as one of a dual-phase nanocrystalline phase, a dual-phase nanocrystalline and amorphous phase, and an amorphous phase.

9. The method of claim 1 , wherein the alloy system is substantially free of a classical segregation-stabilized nanocrystalline phase.

10. The method of claim 1 , wherein (A) comprises calculating a free energy of formation of an intermetallic compound of the alloy system as the third thermodynamic parameter.

11. The method of claim 10 , wherein (A) comprises calculating an enthalpy of mixing of the alloy system as the second thermodynamic parameter.

12. The method of claim 11 , wherein (A) comprises calculating an enthalpy of segregation of the alloy system as the first thermodynamic parameter.

13. The method of claim 12 , wherein (A) further comprises determining a fourth thermodynamic parameter that is a free energy of mixing as a function of at least one of (i) concentration of grain boundary in the alloy system, (ii) grain size of the alloy system, (iii) concentration of the solute element in the alloy system, and (iv) concentration of the solvent element in the alloy system.

14. The method of claim 1 , further comprising electrodepositing a stable phase of the alloy system.

15. The method of claim 1 , further comprising vapor depositing a stable phase of the alloy system.

16. The method of claim 1 , further comprising plasma spraying a stable phase of the alloy system.

17. The method of claim 1 , further comprising mechanically alloying a stable phase of the alloy system.

18. The method of claim 1 , further comprising solidifying a stable phase of the alloy system.

19. The method of claim 1 , wherein the alloy system is a binary alloy system.

20. A non-transitory computer-readable recording medium, comprising a program stored therein that makes an information processor execute the method recited in claim 1 .

21. A system comprising (i) at least one memory storing processor-executable instructions and (ii) at least one information processor coupled to the at least one memory, wherein upon execution of the processor-executable instructions the processor implements the method recited in claim 1 .

Assignees

• Massachusetts Inst Technology

Inventors

• Murdoch Heather A
• Schuh Christopher A

Classifications

• C22C1/11

  Making amorphous alloys · CPC title

• C22C19/03

  based on nickel · CPC title

• G01N25/02 Primary

  by investigating changes of state or changes of phase; by investigating sintering {(investigating or analysing oils or hydrocarbon fluids by measuring cloud point or pour point G01N33/2811)} · CPC title

• C22C27/04

  Alloys based on tungsten or molybdenum · CPC title

• C22C14/00

  Alloys based on titanium · CPC title