球磨时间对高粒径比SiC_p/6061Al复合粉末形貌及复合材料组织与性能的影响

Effect of milling time on morphology of composite powders as well as microstructure and properties of large size ratio SiC/6061Al composites

采用湿磨-高能球磨法对高粒径比的6061Al粉末和SiC混合粉末进行预处理,利用真空热压烧结法制备SiCp/6061Al复合材料。用XRD、SEM、TEM、拉伸强度等测试方法研究球磨时间对复合粉末形貌及复合材料组织和性能的影响。结果表明:在球磨过程中铝粉和SiC颗粒形成复合聚合体,采用乙醇做控制剂,可有效地抑制冷焊反应发生;随球磨时间延长,复合聚合体逐渐变薄并最终断裂;聚合体中碳化硅的含量先增高后降低;铝粉中晶粒尺寸逐渐降低,位错增多;SiC颗粒发生碎化,在基体中分布更加均匀;复合材料的拉伸强度提高,可达到258 MPa。

The large particle size ratio 6061 Al powder and SiC particles mixtures were pretreated by wet-high energy ball milling and subsequently sintered by vacuum hot pressing plus sintering. The effect of milling time on the powders morphology and performance of SiCp/6061 Al composites are studied by XRD, SEM, TEM and tensile strength test. The results show that the combination of mixture powders is generated and the cold weldding reaction is controlled effectually becacuse alcohol is used in the procedure of milling. With the increasing of milling time, the combinational composite is attenuated and fractured at last, the SiC particles content of the composite increases firstly and then decreases; the grain size of Al particles decreases and the dislocations of the Al matrix increases contrarily; the SiC particles break gradually and distribute more uniformly in the matrix, and the tensile strength of the composite increases.