Effect of CuO particle size on synthesis temperature and microstructure of Al2O3p-Al composites from Al-CuO system

Al2O3p-Al composites were synthesized using an in-situ reaction in the 80%Al-20%CuO (mass fraction) system. The effects of the CuO particle size on the synthesis temperature and microstructure of the composites were investigated by various methods. The results indicate that the CuO particle size has a significant effect on the temperature at which the complete reaction in the Al-CuO system occurs: the temperature is 200 °C lower in the Al-CuO system containing CuO particles with sizes less than 6 μm than that containing CuO particles with sizes less than 100 μm. The interfacial bonding between Al2O3 particles and Al is not complete when the temperature is below a critical value. The morphology of the Al2O3 particles varies from ribbon-like shape to near spherical shape when the temperature is above a critical value. These two critical temperatures are affected by the particle size of CuO, and the critical temperature of the sample containing CuO particles with sizes less than 6 μm is 100 °C lower than that of the sample containing CuO particles with sizes less than 100 μm.