Effect of Al(Cr) content on the distribution of Al2O3(Cr2O3) particles formed by internal oxidation

This investigation was conducted to study the effect of Al(Cr) content in Cu-Al(Cr) pre-alloyed powders on the distribution of Al2O3(Cr2O3) particles formed by internal oxidation. The results show that the distribution of Al2O3 particles is different with the change of Al content in Cu-Al system. When the Al content is above 1.2wt.%, the Al2O3 particles tend to distribute along the grain boundaries of copper matrix, whereas when the Al content is above 2.0wt.%, the Al2O3 particles have distributed along the grain boundaries. However, it is interesting to note in Cu-Cr system that most of the formed Cr2O3 particles prefer to distribute in the grain of copper matrix when the Cr content is less than 5wt.%, which is quite different from that of Cu-Al system.