Lead-free projectiles and methods of manufacture

摘要

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 uniaxially pressing and 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 the molten mixture into a mold. A ceramic powder may be added to the copper-iron mixture prior to forming to produce a frangible projectile. The method may further include the step of adding another elemental powder to enhance strength, toughness, density, or hardness.

主权项

1. A method of making a lead-free projectile, comprising the steps of:
producing an iron-copper alloy by melting the metals together at a predetermined ratio of iron to copper; rapidly quenching the molten alloy to produce a fine-grained microstructure with uniformly distributed copper and iron phases, wherein the iron and copper phases are in the range of 50 microns or less in any dimension; and shaping the alloy into a bullet-shaped form a temperature below 1083° C., the melting point of copper.