The attrition-milled powder mixtures of Al and Al2O3 were oxidized below 140$0^{circ}C$ for 1 hr and post-sintered at 150$0^{circ}C$ and 1$600^{circ}C$ for 2 hr. During attrition milling, ZrO2 was added to the system by grinding effect of ZrO2 balls. The average particle size of the powder mixtures was decreased by the attrition milling as the aluminum content decrease. Above 120$0^{circ}C$, sintering behaviro was observed on the fine Al2O3 particles resulted from the oxidation of Al. The specimens heat-treated at 140$0^{circ}C$ for 1 hr showed the bending strength of 166 MPa and hardness of 220 MPa. The specimens post-sintered at 1$600^{circ}C$ for 2hr had a linear shrinkage of 9~12% and a relative density of about 95%. After the post-sintering, the specimens having 55 vol% Al content revealed the bending strength of 513 MPa and hardness of 718 MPa. The Weibull modulus to the bending strength was about 16.