|Publication number||US3888636 A|
|Publication date||Jun 10, 1975|
|Filing date||Nov 10, 1972|
|Priority date||Feb 1, 1971|
|Publication number||US 3888636 A, US 3888636A, US-A-3888636, US3888636 A, US3888636A|
|Inventors||Sczerzenie Francis E, Zaleski Frank I|
|Original Assignee||Us Health|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (68), Classifications (19) |
|External Links: USPTO, USPTO Assignment, Espacenet|
High density, high ductility, high strength tungsten-nickel-iron alloy & process of making therefor
US 3888636 A
United States Patent 1 Sczerzenie et a1.
[ HIGH DENSITY, HIGH DUCTILITY, HIGH STRENGTH TUNGSTEN-NICKEL-IRON ALLOY & PROCESS OF MAKING THEREFOR  Inventors: Francis E. Sczerzenie; Frank I.
Zaleski, both of Philadelphia, Pa.
 Assignee: Government of the United States as represented by the Secretary of the Army, Washington, DC.
22 Filed: Nov. 10, 1972 211 Appl. No; 305,640
Related US. Application Data  Continuation of Ser. No. 111,757, Feb. 1, 1971,
 US. Cl. 29/182; 75/176; 75/227; 102/52  Int. Cl 1322f 5/00; F42b 13/04  Field of Search 102/52; 75/176, 214, 221, 75/224, 227; 148/32, 126; 29/182  References Cited UNITED STATES PATENTS 2,793,951 15/1957 Green et al 75/176 X [4 1 June 10, 1975 Primary Examiner-C. Lovell Attorney, Agent, or Firm-Nathan Edelberg; Robert P. Gibson; Arthur M. Suga [5 7 ABSTRACT A very heavy tungsten alloy for use as armor piercing penetrators and the like, the alloy having high mechanical strength and yet being sufficiently ductile so as not to fracture or fragment upon impact with enemy targets, and preferably comprising about 97.0 weight tungsten, and 1.5 weight each of nickel and iron.
2 Claims, N0 Drawings HIGH DENSITY, HIGH DUCTILITY, HIGH STRENGTH TUNGSTEN-NlCKEL-IRON ALLOY & PROCESS OF MAKING THEREFOR The invention described herein may be manufactured, used and licensed by or for the Government for governmental purpose without the payment to us of any royalty thereon.
This is a continuation of application Ser. No. 111,757, filed Feb. 1, 1971, now abandoned.
This invention relates to heavy metal alloys and more particularly concerns alloys of W-Ni-Fe having high strength and high ductility characteristics Preformed penetrators for armor-piercing projectiles and the like for modern day munitions should desirably be of very high density as well as possessing high strength and ductility. Without sufficient ductility, the penetrator may fragment or fracture upon impact with an enemy target. If the target comprises but a single armor layer, fragmenting of the penetrator upon impact therewith might not be unduly detrimental. However, where enemy targets comprise spaced armored layers, as in many modern tanks and flying craft, it is imperative that the penetrator remain integral upon impact if successful penetration of the layers is to be achieved.
Thus, prior art alloy penetrators, if capable of achieving sufficiently high densities were either brittle and/or of low strength, or, if sufficiently strong and ductile, did not possess a critical density of at least about 18.5 g/cc.
It is therefore an object of this invention to provide a heavy metal alloy having a nominal density of at least about 18.5 g/cc.
Another object is to provide such an alloy having high strength and high ductility properties, thus making it suitable for preformed penetrators for warhead application.
The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the specification that follows.
In accordance with the above objects, we have discovered that a W base alloy which includes minor proportions of Ni and Fe, will yield a highly ductile and strong alloy having a high density.
More specifically, we have found that when about 97.0 weight of W is formed into an alloy containing Ni and Fe in about a l to 1 proportion through our powder metallurgical processes that an alloy having a nominal density of about 18.5 g/cc is achieved while yielding an average elongation in 1 inch of about 1 1%, an ultimate tensile strength averaging 137 ksi. and a yield strength (0.2% offset) of about 100 ksi.
In producing our inventive alloy, we blend fine, high purity tungsten, nickel and iron powders in a suitable apparatus, such as a Twin Shell blender, for example. The powders are at least about 99.9% pure and should pass through a 325 mesh screen, and preferably be of to 40 microns diameter. The blend is conditioned for compaction by a suitable synthetic atomized paraffin wax, preferably 2 to 5 microns in diameter. The wax functions as a die lubricant and to impart green strength to the molded piece. Table I below lists the weight percentages and effective ranges of our alloy compositions.
TABLE I 18.5 g/cc W-Ni-Fe Heavy Alloy The range of tungsten is critical in the above formulations. If the percentage tungsten is reduced below about weight the required nominal density of about 18.5 g/cc will not be achieved. If the tungsten percentage approaches about 98 weight the resultant matrix of Ni and Fe is weak and a high density alloy cannot be achieved.
The ratio of Ni to Fe is preferably 1 to 1, although we have found that ratios of about 40-60 to 60-40 are satisfactory.
The blended powdered metals with synthetic wax are then placed in a die and pressed to a green density compact of at least 1 1.6 g/cc. Any green density lower than about this value produces a sintered piece having a nominal density below 18.5 g/cc.
The pressed compact will now be placed in a furnace at about 540C under a dry (at least 40F dew point) reducing atmosphere (hydrogen or dissociated ammonia) and heated in a period of about 30 minutes to about 875C and maintained at this temperature for about another 30 minutes. The compact will then be rapidly transferred to another furnace also containing a dry reducing atmosphere, but which is maintained at a temperature ranging between about l,460 to 1,600C. At the higher temperature of 1,600C, greater densification results. However, above about 1,600C, the compact bloats and blisters. The compact is held at this temperature for about 1 to 2 hours for densification by liquid phase sintering. The matrix of Ni and Fe liquifies and very considerable shrinkage of the compact occurs after densification has taken place. No traces of the wax remains after this sintering operation. The piece may now be slow cooled and quenched to yield optimum mechanical properties. From a sintering temperature of about 1,600C, it is slow cooled to about 1,300-1,400C in a period of time which is dictated by the mass of the compact or piece. As a general rule, a cooling rate of about 15C/minute for each 40g of mass has been found quite satisfactory. One skilled in this art will know at approximately what rate pieces of varying sizes and masses should be cooled in order that voids will not be present in the piece and to insure total homogeneity in the matrix phase.
After the piece has been sufficiently slow cooled, it is quenched in a water-jacketed cooling chamber having a controlled atmosphere therein of hydrogen or dissociated ammonia.
Further uses for our inventive alloy reside in its effectiveness as an X-ray shield, even more effective than the currently used lead shielding. Our alloy may also be used advantageously in various other applications wherever an extremely high density material is needed.
We wish it to be understood that we do not desire to be limited to the exact details described, for obvious modifications will occur to a person skilled in the art.
1. A preformed penetrator for armor-piercing projectiles comprising an as-sintered alloy having at room temperature, a nominal dendity of 18.5 g/cc, a yield strength (.2% offset) of 100 ksi, an ultimate tensile strength of 137 ksi, an elongation in 1 inch of 1 1%, said alloy produced by the steps of blending fine powders of tungsten, nickel and iron with a minor proportion of an atomized synthetic wax to form a blended mix,
pressing said blended mix to a density of at least 1 1.6
g/cc to form a green compact,
sintering said green compact for densification thereof, and
cooling said densified sintered piece to form a finished piece devoid of voids and a matrix phase of nickel and iron totally homogeneous, said cooling being further characterized by the steps of slow-cooling said sintered piece to a temperature of about 1,300l,400C at a rate of about 15C/minute, and
quenching said slow-cooled piece to below about room temperature in a reducing atmosphere chamber, said alloy consisting of, by weight,
about 97% tungsten,
about 1.5% nickel, and
about 1.5% iron.
2. A process for fabricating an as-sintered heavy tungsten alloy preformed penetrator for use in armor piercing projectiles consisting of, by weight,
about 97% tungsten, about 1.5% nickel, and about 1.5% iron 5 and comprising the steps of blending fine powders of tungsten, nickel and iron with a minor proportion of an atomized synthetic wax to form a blended mix,
pressing said blended mix to a density of at least 1 1.6
g/cc to form a green compact,
sintering said green compact for densification thereof,
and cooling said densified sintered piece to form a finished piece devoid of voids and a matrix phase of nickel and iron totally homogeneous, said finished piece having at room temperature, a nominal density of at least about 18.5 g/cc, a yield strength (.2% offset) of lOOksi, an ultimate tensile strength of 137 ksi, and an elongation in 1 inch of l 1%, said cooling being further characterized by the steps of slow-cooling said sintered piece to a temperature of about 1,3001400C at a rate of about 15C/minute, and
quenching said slow-cooled piece to below about room temperature in a reducing atmosphere cham-
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2793951 *||Jun 18, 1954||May 28, 1957||Gen Electric Co Ltd||Powder metallurgical process for producing dense tungsten alloys|
|US3203349 *||Sep 17, 1963||Aug 31, 1965||Kohlswa Jernverks Ab||Projectile or the like, preferably for armor-piercing weapons, and a method of manufacturing such a projectile|
|US3370535 *||Apr 14, 1960||Feb 27, 1968||Aviation Uk||Armor piercing projectile|
|US3669656 *||May 11, 1970||Jun 13, 1972||Mallory & Co Inc P R||Tungsten base welding rod,method for making same and novel applications of same|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3979209 *||Feb 18, 1975||Sep 7, 1976||The United States Of America As Represented By The United States Energy Research And Development Administration||Ductile tungsten-nickel alloy and method for making same|
|US4458599 *||Aug 27, 1981||Jul 10, 1984||Gte Products Corporation||Frangible tungsten penetrator|
|US4605599 *||Dec 6, 1985||Aug 12, 1986||Teledyne Industries, Incorporated||High density tungsten alloy sheet|
|US4671181 *||Nov 5, 1979||Jun 9, 1987||Rheinmetall Gmbh||Anti-tank shell|
|US4698096 *||Oct 21, 1985||Oct 6, 1987||Rainer Schmidberger||Sintering process|
|US4744944 *||Aug 5, 1987||May 17, 1988||Gte Products Corporation||Process for producing tungsten heavy alloy billets|
|US4762559 *||Jul 30, 1987||Aug 9, 1988||Teledyne Industries, Incorporated||High density tungsten-nickel-iron-cobalt alloys having improved hardness and method for making same|
|US4801330 *||May 12, 1987||Jan 31, 1989||Rensselaer Polytechnic Institute||High strength, high hardness tungsten heavy alloys with molybdenum additions and method|
|US4811666 *||Jan 4, 1988||Mar 14, 1989||Lutfy Eric A||Solid projectiles|
|US4836108 *||Jun 6, 1988||Jun 6, 1989||Gte Products Corporation||Material for multiple component penetrators and penetrators employing same|
|US4851042 *||Jul 18, 1988||Jul 25, 1989||Rensselaer Polytechnic Institute||Hardness and strength of heavy alloys by addition of tantalum|
|US4872409 *||Aug 17, 1987||Oct 10, 1989||Rheinmetall Gmbh||Kinetic-energy projectile having a large length to diameter ratio|
|US4885031 *||Jan 4, 1988||Dec 5, 1989||Gte Products Corporation||Fine grain tungsten heavy alloys containing additives|
|US4888054 *||Jan 21, 1988||Dec 19, 1989||Pond Sr Robert B||Metal composites with fly ash incorporated therein and a process for producing the same|
|US4897117 *||Sep 13, 1988||Jan 30, 1990||Teledyne Industries, Inc.||Hardened penetrators|
|US4931252 *||May 27, 1988||Jun 5, 1990||Cime Bocuze||Process for reducing the disparities in mechanical values of tungsten-nickel-iron alloys|
|US4938799 *||Oct 5, 1988||Jul 3, 1990||Cime Bocuze||Heavy tungsten-nickel-iron alloys with very high mechanical characteristics and process for the production of said alloys|
|US4970960 *||Oct 18, 1989||Nov 20, 1990||Feldmann Fritz K||Anti-material projectile|
|US4990195 *||Jan 3, 1989||Feb 5, 1991||Gte Products Corporation||Process for producing tungsten heavy alloys|
|US5008071 *||Nov 25, 1988||Apr 16, 1991||Gte Products Corporation||Method for producing improved tungsten nickel iron alloys|
|US5306364 *||Jun 9, 1992||Apr 26, 1994||Agency For Defense Development||High toughness tungsten based heavy alloy containing La and Ca. manufacturing thereof|
|US5377880 *||Nov 10, 1993||Jan 3, 1995||Lumson S.R.L.||Fluid substance dispenser with deformable head|
|US5523048 *||Jul 29, 1994||Jun 4, 1996||Alliant Techsystems Inc.||Method for producing high density refractory metal warhead liners from single phase materials|
|US5789698 *||Jan 30, 1997||Aug 4, 1998||Cove Corporation||Projectile for ammunition cartridge|
|US5821441 *||Feb 27, 1996||Oct 13, 1998||Sumitomo Electric Industries, Ltd.||Tough and corrosion-resistant tungsten based sintered alloy and method of preparing the same|
|US5847313 *||Aug 28, 1997||Dec 8, 1998||Cove Corporation||Projectile for ammunition cartridge|
|US5863492 *||Jun 13, 1997||Jan 26, 1999||Southwest Research Institute||Ternary heavy alloy based on tungsten-nickel-manganese|
|US5956558 *||Apr 30, 1997||Sep 21, 1999||Agency For Defense Development||Fabrication method for tungsten heavy alloy|
|US6136105 *||Jun 12, 1998||Oct 24, 2000||Lockheed Martin Corporation||Process for imparting high strength, ductility, and toughness to tungsten heavy alloy (WHA) materials|
|US6156093 *||Dec 14, 1999||Dec 5, 2000||Lockheed Martin Corporation||High strength, ductility, and toughness tungsten heavy alloy (WHA) materials|
|US6413294 *||Jun 23, 2000||Jul 2, 2002||Lockheed Martin Corporation||Process for imparting high strength, ductility, and toughness to tungsten heavy alloy (WHA) materials|
|US6447715 *||Jan 14, 2000||Sep 10, 2002||Darryl D. Amick||Methods for producing medium-density articles from high-density tungsten alloys|
|US6551376||Apr 21, 2000||Apr 22, 2003||Doris Nebel Beal Inter Vivos Patent Trust||Method for developing and sustaining uniform distribution of a plurality of metal powders of different densities in a mixture of such metal powders|
|US6607692||Dec 31, 2001||Aug 19, 2003||Doris Nebel Beal Intervivos Patent Trust||Method of manufacture of a powder-based firearm ammunition projectile employing electrostatic charge|
|US6749802||Jan 30, 2002||Jun 15, 2004||Darryl D. Amick||Pressing process for tungsten articles|
|US6823798||Oct 17, 2003||Nov 30, 2004||Darryl D. Amick||Tungsten-containing articles and methods for forming the same|
|US6827756 *||Jan 17, 2003||Dec 7, 2004||Poongsan Corporation||Tungsten heavy alloy for penetrating splinter shell and forming method thereof|
|US6884276||Sep 9, 2002||Apr 26, 2005||Darryl D. Amick||Methods for producing medium-density articles from high-density tungsten alloys|
|US6960319 *||Oct 27, 1995||Nov 1, 2005||The United States Of America As Represented By The Secretary Of The Army||Tungsten alloys for penetrator application and method of making the same|
|US7000547||Oct 29, 2003||Feb 21, 2006||Amick Darryl D||Tungsten-containing firearm slug|
|US7059233||Oct 31, 2003||Jun 13, 2006||Amick Darryl D||Tungsten-containing articles and methods for forming the same|
|US7175803 *||Jun 14, 2004||Feb 13, 2007||Varian Medical Systems Technologies, Inc.||X-ray tube and method of manufacture|
|US7217389||Jan 7, 2002||May 15, 2007||Amick Darryl D||Tungsten-containing articles and methods for forming the same|
|US7329382||Apr 25, 2005||Feb 12, 2008||Amick Darryl D||Methods for producing medium-density articles from high-density tungsten alloys|
|US7383776||Apr 9, 2004||Jun 10, 2008||Amick Darryl D||System and method for processing ferrotungsten and other tungsten alloys, articles formed therefrom and methods for detecting the same|
|US7399334||May 10, 2005||Jul 15, 2008||Spherical Precision, Inc.||High density nontoxic projectiles and other articles, and methods for making the same|
|US7422720||May 10, 2005||Sep 9, 2008||Spherical Precision, Inc.||High density nontoxic projectiles and other articles, and methods for making the same|
|US7547345 *||Feb 22, 2002||Jun 16, 2009||Halliburton Energy Services, Inc.||High performance powdered metal mixtures for shaped charge liners|
|US7637161||Apr 19, 2006||Dec 29, 2009||Raytheon Utd Inc.||Substrate penetrating acoustic sensor|
|US7690312 *||Jan 20, 2005||Apr 6, 2010||Smith Timothy G||Tungsten-iron projectile|
|US7770521 *||Jun 3, 2005||Aug 10, 2010||Newtec Services Group, Inc.||Method and apparatus for a projectile incorporating a metastable interstitial composite material|
|US7811354||May 31, 2009||Oct 12, 2010||Halliburton Energy Services, Inc.||High performance powdered metal mixtures for shaped charge liners|
|US7886666||Feb 24, 2010||Feb 15, 2011||Newtec Services Group, Inc.||Method and apparatus for a projectile incorporating a metastable interstitial composite material|
|US7950330 *||Feb 18, 2010||May 31, 2011||Continuous Metal Technology, Inc.||Tungsten-iron projectile|
|US8001879||Jan 5, 2011||Aug 23, 2011||Newtec Services Group, Inc.||Method and apparatus for a projectile incorporating a metastable interstitial composite material|
|US8122832||May 11, 2007||Feb 28, 2012||Spherical Precision, Inc.||Projectiles for shotgun shells and the like, and methods of manufacturing the same|
|US8230789||Aug 23, 2011||Jul 31, 2012||Nowtec Services Group, Inc.||Method and apparatus for a projectile incorporating a metastable interstitial composite material|
|US8985026||Nov 20, 2012||Mar 24, 2015||Alliant Techsystems Inc.||Penetrator round assembly|
|CN102091859A *||Dec 28, 2010||Jun 15, 2011||西安华山钨制品有限公司||High-density tungsten alloy complex part molding process|
|CN102091859B||Dec 28, 2010||Jan 9, 2013||西安华山钨制品有限公司||High-density tungsten alloy complex part molding process|
|EP0297001A1 *||Jun 21, 1988||Dec 28, 1988||Cime Bocuze||Process for decreasing the range of values of the mechanical characteristics of tungsten-nickel-iron alloys|
|EP0326713A1 *||Dec 29, 1988||Aug 9, 1989||GTE Products Corporation||Improved tungsten nickel iron alloys|
|EP0769131A1 *||Jun 29, 1995||Apr 23, 1997||Lockheed Martin Energy Systems, Inc.||Non-lead, environmentally safe projectiles and method of making same|
|EP0779966A2 *||Jun 5, 1996||Jun 25, 1997||Lockheed Martin Energy Systems, Inc.||Non-lead, environmentally safe projectiles and explosives containers|
|EP0997700A1 *||Oct 30, 1998||May 3, 2000||SM Schweizerische Munitionsunternehmung AG||Non-polluting jacketed bullet and manufacturing method therefor|
|WO2000026605A1 *||Oct 18, 1999||May 11, 2000||Olivier Chene||Production of a low-polluting jacketed bullet|
|WO2003027340A1 *||Sep 20, 2002||Apr 3, 2003||Cime Bocuze||High-power tungsten-based sintered alloy|
|WO2008051278A2 *||Mar 21, 2007||May 2, 2008||Benjamin Dolgin||Substrate penetrating acoustic sensor|
| || |
|U.S. Classification||75/248, 419/25, 102/501, 75/230, 420/430|
|International Classification||F42B12/00, B22F3/24, C22C27/00, C22C27/04, F42B12/74, C22C1/04|
|Cooperative Classification||F42B12/74, C22C1/045, B22F3/24, C22C27/04|
|European Classification||C22C27/04, C22C1/04F, B22F3/24, F42B12/74|