nano-SiC_p/Al复合材料的高能球磨制备工艺

Fabrication of nano-SiC_p/Al composite by high energy ball milling

采用高能球磨粉末冶金法制备了10vol%nano-SiC颗粒增强纯Al基复合材料,研究了球磨时间和硬脂酸含量对复合粉末粒度和纳米颗粒分散均匀性的影响规律,并对复合材料的微观结构和拉伸性能进行了研究。结果表明,随球磨时间的延长,SiC颗粒在Al中的分散均匀性变好,而复合粉颗粒的粒径先减小后增大,在球磨时间为15h、过程控制剂硬脂酸含量为2wt%时复合粉末粒径最小。并采用此优化的混料工艺,制备出综合性能良好的nano-SiCp/Al复合材料,其抗拉强度达到392.7MPa,较纯Al提高了164.9%,伸长率达10.41%,较纯Al有所下降。复合材料的断裂机制是微孔聚集型断裂。

The aluminum matrix composite reinforced by 10vol% nano-SiC particles was fabricated by powder metallurgical process with high energy ball milling. Effects of milling time on both the composite powder size and the nano particles distribution were determined, as well as the microstructure and tensile properties of the composite were studied. The results indicate that with increasing milling time, the size of composite powders decreases first and then increases ,and reaches the smallest size for milling 15 h using 2wt% stearic acid as process control agents（PCA）. In addition, the distribution of SiCppartieles is improved. Using the optimum milling time and PCA content, nano-SiCp/Al composite with excellent comprehensive properties was fabricated successfully. The tensile strength of the obtained composite reaches 392. 7 MPa,increasing by 164. 9% compared with that of pure Al. While,the elongation shows a little decline and reaches 10. 41%. The fracture mechanism of composite is dimple mode.