Effect of Al content on the properties and microstructure of Al2O3-Cu composite prepared by internal oxidation

摘要

Combining high-energy milling with internal oxidation, Al2O3-Cu composite was prepared. The effect of Al content on hardness and electrical conductivity of the composite material was studied. The exothermic effect of Al resulting from internal oxidation during fabricating Al2O3-Cu composite was also calculated and discussed. The results show that Al content has a great effect on the properties and microstructure of the Al2O3-Cu composite. When Al content is less than 0.8 wt% and the internal oxidation temperature is at 1223 K, the properties of the composite are improved with the increase in Al content. In contrary, the properties of the composite will decrease while the Al content is more than 0.8 wt%. The main reason for this case is the melting of a part of Cu resulting from the greater exothermic effect with increasing Al content. The influence of exothermic effect on the oxidation and sintering temperature is predominant for the specimen preparing procedure. In this context, the choices of heating rate and the internal oxidation temperature should be varied with Al content.