纳米Al_(2)O_3/2024铝基复合材料的显微组织及力学性能

Microstructure and Mechanical Properties of Nano-Al2O3/2024 Aluminum Matrix Composites

利用球磨预分散-搅拌铸造法制备纳米Al2O3/2024复合材料,并对所制备的铝基复合材料进行了显微组织及力学性能的研究。结果表明,经球磨预分散后,纳米颗粒团聚现象明显消除,纳米Al2O3呈单颗粒分散于Al粉表面;复合粉体添加法有效避免了超细增强颗粒和基体润湿性差和分散性较差的问题,实现纳米Al2O3颗粒均匀弥散分布于基体合金中;纳米Al2O3颗粒的加入显著提高基体合金的力学性能。与传统搅拌铸造相比,所制备的Al2O3/2024复合材料的抗拉强度、屈服强度和显微硬度分别提高了58%、59%和16%。

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.