Synthesis and properties of nanocrystalline nonferrous metals prepared by flow-levitation-molding method
来源期刊:中国有色金属学报(英文版)2007年第6期
论文作者:刘伟 杨天足 楚广 罗江山 唐永建
文章页码:1347 - 1351
Key words:nanocrystalline; nonferrous metals; flow-levitation-molding; density; microhardness; electrical resistivity
Abstract: Nanocrystalline nonferrous metals (Cu, Al, and Ag) were synthesized by flow-levitation-molding method. The microstructure of the as-prepared nanocrystalline metals was characterized by XRD and FESEM. The microhardness and electrical resistivity were tested by the HMV-2 type Microhardness Tester and 6157 type Electrometer, respectively. The synthesis process was also studied. The results show that the spheriform particles in nanocrystalline metals have average grain size of 20-30 nm. The relative density of nanocrystalline Cu, Al, and Ag are 95.1%, 98.1% and 98.3%, respectively. The microhardness of nanocrystalline Cu, Al and Ag are 2.01, 2.11 and 1.26 GPa respectively, which are larger than those of their coarse-grained counterparts by the factor of 4.5, 14, and 2.5, respectively. The electrical resistivity of nanocrytalline Cu at room temperature is 1.5×10-7 Ω·m, which is higher than coarse-grained Cu by a factor of 7.5. The pressure is the predominant factor influencing the density of the as-prepared nanocrystalline nonferrous metals.
基金信息:the National Natural Science Foundation of China