Impact and Static Consolidation of Mechanically-Alloyed Mixture of Copper and Graphite Powders.

A mixture of copper and carbon powders was mechanically alloyed in a planetary ball mill. The supersaturated solid solubility of carbon in mechanically-alloyed copper is 25 at% C, as determined from the lattice parameter change. The supersaturated powder consolidated by static compression at 1.4 GPa, has the relative density of 95%, a Vickers hardness of 121, and a compressive strength of 1.4 GPa. In contrast, powder consolidated dynamically by a 90.1 g projectile traveling at a velocity of 38.1 m/s and at an estimated impact compression of 2.3 GPa after 0.4 GPa static precompression has a relative density of 96.3% and a Vickers hardness of 200. X-ray diffraction patterns shift to higher angles after impact compression. The supersaturated solid solubility of 18 at% C in Cu+20 at% C mechanically-alloyed powders was reduced to 12.5 at% C by impact compression. Mechanically-alloyed powders can be consolidated by impact and static pressures while retaining the effects of mechanical alloying; for example, supersaturated solid solubility. [ABSTRACT FROM AUTHOR]