Ternary heavy alloy based on tungsten-nickel-manganese

• US 5,863,492 A
• Filed: 06/13/1997
• Issued: 01/26/1999
• Est. Priority Date: 04/16/1991
• Status: Expired due to Fees

• Current Assignee: Southwest Research Institute
• Original Assignee: Southwest Research Institute
• Inventors: Bose, Animesh
• Primary Examiner(s): Simmons, David A.
• Assistant Examiner(s): Koehler, Robert R.
• Application Number:
  US08/874,360
• Time in Patent Office: 592 Days
• Field of Search: 420/430, 419/38
• US Class Current: 420/430
• CPC Class Codes: B22F 2201/013 Hydrogen
• CPC Class Codes: B22F 2201/11 Argon
• CPC Class Codes: B22F 3/101 Changing atmosphere
• CPC Class Codes: C22C 1/045 Alloys based on refractory metals
• CPC Class Codes: C22F 1/18 High-melting or refractory metals or alloys based thereon
• CPC Class Codes: F42B 12/74 of the core or solid body

Abstract

A high density, high strength and high compressive strain tungsten heavy alloy consists essentially of tungsten in the amount of approximately 90% by weight, and the rest Mn and Ni in an amount sufficient to cause sintering at between 1100° and 1400° C. The W-Ni-Mn alloy exhibits characteristics of intense shear bands (which could indicate failure by adiabatic shear during high strain-rate dynamic testing) thus making it an attractive material for kinetic energy penetrators. Moreover, the alloy provides an inexpensive high density material which can be produced in furnaces for conventional ferrous powder metal part manufacturing and other conventional non-ferrous powder metal part manufacturing by lowering the sintering temperature by 2000° to 300° C.

Claims

1. A tungsten heavy alloy based on W-Ni-Mn having high density, high strength, and high compressive strains consisting essentially of:

W in the amount of at least 80% by weight; and

the remaining amount of Mn and Ni in a sufficient amount to lower the sintering temperature of said alloy to between 1100° and

1400°

C.

2. The heavy alloy of claim 1, further comprising a sufficient amount of Mn to cause said alloy to fail in adiabatic shear when said alloy undergoes a high strain rate.

3. The alloy of claim 1, wherein said Mn is in the amount of approximately 6% by weight;

and said Ni is in the amount of 4% by weight.

4. The alloy of claim 1, wherein said Mn is in the amount sufficient to cause a sintering temperature of between 1100°

and 1300°

C.

5. The alloy of claim 1, wherein the sintered density of said alloy is approximately 15.72 to approximately 16.07 grams per cubic centimeter for sintering temperatures in a range from 1100°

centigrade to 130°

centigrade.

6. The alloy of claim 1, wherein said alloy has an average grain size of approximately less than 10 microns for sintering temperatures less than 1300°

centigrade.

7. The alloy of claim 1, wherein said alloy may be plastically deformed to a strain of at least 0.30 in compression.

8. The tungsten heavy alloy of claim 1 having high density, high strength, and high compressive strains, said alloy having a surface comprising:

a plurality of light metallic grains consisting essentially of a pure W; and

a plurality of alloy matrices comprising W, Mn, and Ni, said matrices of a grayish shade darker than said light metallic grains, said matrices interspersed with said light metallic grains.