Lead-free, corrosion-resistant projectiles and methods of manufacture
US9188416B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2015 |
| Grant date | Nov 17, 2015 |
| Priority date | — |
| Expiry date | Jun 12, 2035 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF42B8/14
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
To produce lead-free projectiles, iron and copper are melted at a predetermined ratio and rapidly quenched to yield a fine-grained microstructure with uniformly distributed copper and iron phases. The iron-copper alloy may be made into a powder through atomization, with the iron-copper molten metal being dispersed using a rapidly moving gas, liquid stream, or via mechanical dispersion. The step of forming the bullet may include solid-state sintering of the atomized powder, including heating at a temperature below 1083° C., the melting point of copper. Alternatively, the step of shaping the mixture into a bullet-shaped form may include casting and/or uniaxially pressing the mixture into a mold. A ceramic powder may be added to the copper-iron mixture prior to forming to produce a frangible projectile. Chromium, including chromium from recycled stainless steel, may be added to increase corrosion resistance and/or reduce manufacturing cost.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.