Bulk Nanostructured Cu-2.5vol.Al_2O_3 Alloy Synthesized Using High Energy Mechanical Milling

摘要

Fully dense bulk nanostructured lumps, balls and disks of Cu-2.5vol.%Al_2O_3 alloy with various grain sizes were produced by using different high energy mechanical milling routes. It has been found that with room temperature milling only, the powder particles are first gradually turned into lumps and then the lumps are turned into balls and disks. In the meantime, the average grain size of the Cu phase decreases with milling time. Cryomilling causes a decrease of the grain size, but has no consolidation effect. It is clear that a combination of cryomilling and room temperature milling is much more effective than just room temperature milling in producing the bulk nanostructured Cu alloy. The highest hardness achieved is 2.5GPa. It appears that the small volume fraction of Al_2O_3 nanoparticles significantly strengthens the Cu alloy.