High-strength nanostructured alloys

• US 7,815,850 B2
• Filed: 09/07/2006
• Issued: 10/19/2010
• Est. Priority Date: 03/09/2004
• Status: Active Grant

• Current Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Original Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Inventors: Wittmann, Markus Wolfgang, Hanna, James Anthony, Baker, Ian
• Primary Examiner(s): King; Roy
• Assistant Examiner(s): KIECHLE, CAITLIN ANNE
• Application Number:
  US11/517,036
• Publication Number:
  US 20070187010A1
• Time in Patent Office: 1,503 Days
• Field of Search: 148/442, 420/581
• US Class Current: 420/581
• CPC Class Codes: C22C 1/00 Making non-ferrous alloys by electrothermic methods C22B4/00; by electrolysis C25C1/24, C25C3/36
• CPC Class Codes: C22C 19/03 based on nickel
• CPC Class Codes: C22C 22/00 Alloys based on manganese
• CPC Class Codes: C22C 30/00 Alloys containing less than 50% by weight of each constituent
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/08 containing nickel C22C38/105 takes precedence

Abstract

Biphasic alloys, formed through a spinodal decomposition process, are disclosed. The alloys have improved strength and hardness, over single phase alloys, due to coherency strain between the phases. They are prepared from readily available transition metals, and they can be used to make large, high-strength parts, for example, of types that cannot be made by extrusion, forging or cold working techniques.

Claims

1. An intermetallic composition formed by spinodal decomposition in at least two distinct structural phases, each of said phases being quaternary, and the intermetallic composition having an average composition comprising from 9% to 41% iron, 9% to 41% nickel, 9% to 41% manganese and 9% to 41% aluminum, wherein the composition is described in terms of atomic percentages.

2. The intermetallic composition of claim 1, wherein the microscopic content varies with localized nanostructure.

3. The intermetallic composition of claim 1, wherein the composition comprises 30% iron, 20% nickel, 25% manganese and 25% aluminum.

4. The intermetallic composition of claim 3, wherein the composition comprises a yield strength of at least 1400 MPa at room temperature.

5. The intermetallic composition of claim 3, wherein the composition comprises a yield strength of at least 2000 MPa at room temperature.

6. The intermetallic composition of claim 1, further comprising a coating.

7. The intermetallic composition of claim 6, wherein the coating is selected from the group consisting of polymeric coatings, silicon-based coatings, metal oxide coatings, gold, platinum, silver, carbon-based coatings, adhesives, and combinations thereof.

8. An intermetallic composition formed by spinodal decomposition in at least two distinct body-centered cubic structural phases, each of said phases being quaternary, and the intermetallic composition having an average composition comprising from 9% to 41% iron, 9% to 41% nickel, 9% to 41% manganese and 9% to 41% aluminum, wherein the composition is described in terms of atomic percentages.

9. The intermetallic composition of claim 8, wherein the composition comprises 30% iron, 20% nickel, 25% manganese and 25% aluminum.