Frangible metal bullets, ammunition and method of making such articles
AssigneeSinterFire Inc.
InventorJoseph C. Benini
Life of this patent
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Abstract
A frangible metal bullet, a method for making it, and ammunition made therefrom. The frangible metal bullet is formed from a mixture of metal particles and metal or metalloid binder forming material which is compacted into the desired shape, heated to a temperature above that needed to form at least one intermetallic compound but below the temperature of joining of the metal particles by sintering and below the temperature of formation of substantial amounts of a ductile alloy of the metal of the particles and the metal or metalloid binder forming material and then cooled. Such bullets have sufficient strength to maintain their integrity during firing but disintegrate into powder on impact and can be formulated to be lead-free.
Claims23
A frangible metal bullet comprising:
- a plurality of metal particles;
- a brittle binder for joining said metal particles, said binder consisting essentially of at least one intermetallic compound.
A frangible, lead-free, metal bullet comprising:
- a plurality of metal particles, said metal being selected from the group consisting of:
- copper, copper-base alloys, iron, nickel and chromium;
- a metal or metalloid binder forming material disposed to form a brittle binder comprised of at least one intermetallic compound at a treatment temperature below the temperature of metal particle to metal particle bonding or the formation of significant quantities of a binder/metal particle alloy.
A frangible metal bullet comprising:
- a plurality of unsintered metal particles;
- an intermetallic compound binder joining said metal particles to form said metal bullet.
A method of making a frangible metal bullet, said method comprising the steps of:
- forming a mixture comprising metal particles and a metal or metalloid binder forming material disposed to form at least one intermetallic compound at a treatment temperature below the temperature for joining said metal particles and formation of substantial amounts of a ductile alloy of said metal particles and said binder forming material;
- compacting said mixture to form a green compact in the shape of said bullet;
- heating said green compact to said treatment temperature for a time sufficient to form an effective amount of at least one brittle intermetallic compound, thereby forming a shaped metal precursor;
- and
- returning said metal precursor to room temperature to form said frangible metal bullet.
A lead-free cartridge comprising:
- a cartridge case having a neck;
- a lead-free primer composition;
- propellant within said case;
- and
- a frangible, lead-free, metal bullet comprised of a plurality of unsintered metal particles joined with a brittle binder consisting essentially of at least one intermetallic compound formed from a binder forming material, said metal particles comprising a metal selected from the group consisting of copper, iron, nickel, chromium, tungsten and their alloys, said bullet being in said case neck.
Dependencies are inferred from the claim text.