Microstructure and hardness of MWCNTs/Al composite by friction stir processing
-
摘要: 采用搅拌摩擦加工技术(FSP)制备多壁碳纳米管增强铝基(MWCNTs/Al)复合材料, 并对该复合材料的显微结构和硬度进行分析。结果表明: MWCNTs/Al复合材料显微结构为细小的等轴晶, 晶粒大小不均匀; MWCNTs与Al基体界面结合良好, 界面处分布大量的位错, MWCNTs主要分布在晶内; 动态再结晶形核方式为亚晶形核, 在原始晶粒和已形成的亚晶内形核, 经动态再结晶使晶粒逐步细化; MWCNTs/Al复合材料的硬度随MWCNTs含量增加呈上升的趋势, 当CNTs体积分数为6%时, MWCNTs/Al复合材料硬度达HV 63.4, 为纯Al经5次FSP硬度的1.9倍。Abstract: Multi-walled carbon nanotubes(MWCNTs) reinforced Al matrix composites were prepared by friction stir processing(FSP). The microstructure and hardness of the composites were investigated. The results show that the MWCNTS/Al is composed of fine equiaxed grains but the grains are uneven. The interface between MWCNTs and the matrix is well binded. A large numbers of dislocations were distributed in the interface. MWCNTs mainly distributed within the aluminum grains. The grain refinement is realized by recrystallization through a subcrystal nucleating mode. The nucleis form nucleus in the primary grains and the formed subcrystal. Therefore, the grains are refined gradually. With increasing MWCNTs content, the hardness of MWCNTs/Al composite increases. When the volume fraction of MWCNTs is 6%, the microhardness is HV 63.4 which is 1.9 times as hard as Al made after 5 times of FSP.
-
Key words:
- friction stir processing /
- carbon nanotubes(CNTs) /
- equiaxed grain /
- grain refinement /
- hardness
-
点击查看大图
计量
- 文章访问数: 1181
- PDF下载量: 795
- 被引次数: 0
下载:
