Nano-Al2O3/2024 composites were fabricated by the pre-dispersion of ball milling and stirring casting

and microstructure and properties of the composites were investigated.The results show that the particles clustering in the as-received powder are eliminated effectively after the pre-dispersion treat ment of ball-milling

and the isolated Al2O3 nano-particles are uniformly dispersed on the surface of Al powder.Addition of the milled nano-Al2O3/Al composite powder instead of raw nano-particles can alleviate the problems associated with poor wettability

agglomeration and the nano-particle dispersion in the melt

realizing the homogeneous distribution of the nano-particle in the matrix.Mechanical properties of the composites are improved remarkably with introducing nano-particle.Compared with those of the composites prepared by conventional stirring casting

the tensile strength

yield strength and micro-hardness of the prepared Al2O3/2024 composites are increased by 59%

58% and 67%

respectively.