Pressing process for tungsten articles
OwnerDarryl D. Amickinventor
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Abstract
A manufacturing process for articles that are formed from powders containing tungsten and at least one binder. The manufacturing process includes compacting the mixture of powders under a first pressure to yield a desired intermediate structure, then reshaping the structure under a second pressure that is lower than the first pressure to yield the desired article. The binder utilized in the manufacturing process may include a metallic binder or a non-metallic binder, or both. The process is particularly suited for the manufacture of lead substitutes, including firearms projectiles, such as a bullet or shot. Such projectiles may be ferromagnetic or non-ferromagnetic, frangible or infrangible, and jacketed or unjacketed.
Claims55
A method for forming a tungsten-containing article, the method comprising:
- compacting a mixture comprising a tungsten-containing powder and a binder under a first pressure to yield an intermediate structure;
- and
- reshaping the structure by applying a second pressure that is lower than the first pressure to yield a tungsten-containing article having a different shape than the intermediate structure.
A method of manufacturing a firearms projectile, the method comprising:
- placing a mixture comprising a tungsten-containing powder and a binder into a die;
- applying a first pressure to the mixture to produce an intermediate structure, wherein the first pressure is applied by a compaction die assembly that includes a pair of punches having mixture-engaging faces adapted to engage the mixture as the first pressure is applied;
- and
- reshaping the intermediate structure by applying a second pressure to the intermediate structure to produce an article selected from the group consisting of a bullet and a bullet core, wherein the second pressure is lower than the first pressure, wherein the second pressure is applied by a reshaping punch assembly having a pair of punches with structure-engaging faces adapted to engage the intermediate structure as the second pressure is applied, and further wherein the article has a density that is greater than 9 g/cc, and further wherein the article has a shape that is different than the shape of the intermediate structure.
Dependencies are inferred from the claim text.