Mechanically alloyed nanocrystalline Cu80Co20 investigated by AP/FIM and 3DAP

The Cu80Co20 was mechanically alloyed from the pure elements by ball milling during 28 hours. The powder was compacted into tablets at room temperature applying a pressure of 0.5 GPa. Microstructural investigations of the as-prepared alloy, and after annealing at 400 degrees C for 2 hours in vacuum were carried out by atom probe field ion microscopy (AP/FIM) and three dimensional atom probe (3DAP). A nanocrystalline structure of the mechanically alloyed Cu80Co20 was observed by FIM with grain sizes between 15 and 80 nm. AP/FIM and 3DAP measurements indicate the as-prepared state as a highly supersaturated alloy, which after heat treatment showed nanocrystalline Co precipitates with a Cu content of about 1.3 at. %.