Fe-ni-mn-al-cr alloys and methods for production thereof

Inactive Publication Date: 2014-09-25
TRUSTEES OF DARTMOUTH COLLEGE THE +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides alloys with exceptional strength and ductility. The alloys have an average composition of 25% to 35% iron, 15% to 25% nickel, 30% to 40% manganese, 10% to 20% aluminum, and the remainder consisting of at least one of chromium, molybdenum, cobalt, and aluminum. The alloys have a unique structure with two distinct structural phases, which can be a face-centered cubic phase or a body-centered cubic phase. The concentration of iron and manganese in the f.c.c. phase is greater than the amount of nickel or aluminum. The addition of chromium to the alloy results in improved resistance to corrosion and oxidation. The alloys can be used in various applications such as aerospace, automotive, and industrial applications.

Problems solved by technology

Equipment that incorporates these new materials in component parts may have a longer service life, require less maintenance or achieve an improved performance level.

Method used

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  • Fe-ni-mn-al-cr alloys and methods for production thereof
  • Fe-ni-mn-al-cr alloys and methods for production thereof
  • Fe-ni-mn-al-cr alloys and methods for production thereof

Examples

Experimental program
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Effect test

example 1

Preparation and Characterization of Fe30Ni20Mn35Al15

[0062]A quaternary alloy of Fe30Ni20Mn35Al15 composition was prepared by well known arc melting and casting techniques. A quantity of material including 24 g Fe, 17 g Ni, 27 g Mn and 5 g Al was placed in a water-cooled copper mold and heated until molten using the arc melting technique. Ingots were flipped and melted a minimum of three times under argon to ensure mixing. Quenching was done by allowing the alloy to rapidly cool in the copper mold to a temperature of ˜30° C. in approximately 10 minutes. A eutectic transformation was carried out by holding the quenched ingots at about 1215° C. for about 30 minutes. For this composition, the eutectic transformation temperature, as shown in the differential thermal analysis curve, was between about 1210-1290° C., or between about 1212-1250° C. or between about 1214-1230° C. In some embodiments, a 5% excess of Mn may be added to the starting materials because Mn accounts for the majorit...

example 2

Preparation and Characterization of FexNi50-xMn50-yAly±5%

[0074]Various alloys are cast with a composition:

FexNi50-xMn50-yAly,  Formula (2)

where x ranges from 25 to 35 atomic percent plus or minus 5%, and y ranges from 10 to 20 atomic percent plus or minus 5%.

[0075]The alloys are cast using the aforementioned arc melting technique and heated to a eutectic transformation temperature range of between about 1210-1290° C., or between about 1212-1250° C. or between about 1214-1230° C. The alloys are expected to be strong and ductile with a range of mechanical properties that can be manipulated by composition variations within the disclosed range.

[0076]FIGS. 9A-C show SEM images of (a) Fe28Ni18Mn33Al21; (b) Fe29Ni19Mn34Al18 and (c) Fe28Ni21Mn33Al18.In these images the B2 phase is brighter and the f.c.c. phase darker. The B2 and f.c.c. structures of the Fe28Ni18Mn33Al21 alloy are finer than those of the other two alloys.

[0077]FIGS. 10A-D show SEM images of: (a) Fe31Ni18Mn38Al13; (b) Fe29Ni1...

example 3

[0080]Characterization of a Phase Diagram Near a Eutectic Transformation

[0081]A portion of a phase diagram near a eutectic transformation may be constructed by varying percentages of Fe, Ni, Mn, Al and M as described in the context of Formula (1), except the subscripts a, b, c, d, and e, may be any value. The constituents are processed as described in Examples 1 and 2 to ascertain the presence or absence of eutectic transformation products. The preferred metals include combinations of Fe, Ni, Mn, and Al, in which case the ranges for x and y shown in Formula (2) may be any value. When adjusting the respective subscripts a, b, c, d, e, x and / or y, it is suggested to increase or decrease the individual ranges or combinations of ranges in steps of five percent from the values shown in Formulas (1) and (2), at least until the resulting alloy does not show evidence of a eutectic transformation. For alloys that contain four or five constituents, it is routine in the art that several hundre...

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Abstract

Alloys including iron, nickel, manganese, aluminum and chromium are disclosed. The alloys have high strength and ductility. The alloys are prepared from readily available transition metals, and can be used in applications where properties similar to steel are necessary or advantageous.

Description

RELATED APPLICATIONS[0001]This application is a continuation in part application of U.S. application Ser. No. 12 / 867,712, international filing date Feb. 13, 2009 which is hereby incorporated by reference and which is the national stage of International Application No. PCT / US09 / 34123, filed Feb. 13, 2009, which claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61 / 028,809, filed Feb. 14, 2008, which is incorporated by reference herein.GOVERNMENT INTERESTS[0002]The United States Government has rights in this invention under Contract No. NSF-DMR-0505774 and NSF DMR-0905229 between the National Science Foundation (NSF) and Dartmouth College and also under Contract DE-FG02-07ER46392, between the U.S. Department of Energy and Dartmouth College.BACKGROUND[0003]1. Field of the Invention[0004]This invention relates to novel alloys and methods of producing the alloys. More specifically, the alloys are strong and ductile microstructured alloys having lamellar struct...

Claims

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Application Information

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IPC IPC(8): C22C30/00C22C22/00C22C38/04C22C38/08C22C38/06
CPCC22C30/00C22C38/08C22C22/00C22C38/04C22C38/06C22F1/16
InventorBAKER, IANMENG, FANLINGQIU, JINGWEN
OwnerTRUSTEES OF DARTMOUTH COLLEGE THE