高能球磨时间对W-Cu纳米晶复合粉体组织和性能的影响

Effect of ball milling time on microstructure and properties of nanocrystalline W-Cu composite powder

采用机械合金化法制备W-20%Cu(质量分数)纳米晶复合粉体。通过XRD,SEM等方法对球磨后的复合粉体进行表征,研究球磨时间对复合粉体的物相成分、晶粒尺寸、微观应变以及表面形貌的影响,并探讨机械合金化过程中过饱和固溶体的形成机制。结果表明:随着球磨时间的延长,W的晶粒尺寸及晶格常数不断减小,微观应变逐渐增大;球磨40 h后W的平均晶粒尺寸为22 nm左右;机械合金化工艺可显著提高Cu在W中的固溶度;复合粉体的最终形态为细小均匀的颗粒状。

Nanocrystalline W-20%Cu （mass fraction） composite powder were fabricated by mechanical alloying （MA）. The as-milled composite powder was characterized by XRD and SEM, respectively. The effect of milling time on the phase components, crystallite size, microstrain and morphology of the composites were studied, the mechanism of forming supersaturated solid solution during MA was also investigated. The results show that crystallite size and lattice parameter of W-Cu powder decrease with increasing ball milling time, whereas the mircostrain increase. When the powder was ball milled for 40 h, the average crystalline size of the W was about 22 nm; the solid solubility of Cu dissolved in W is largely extended after 40 h ball milling and the structure of the powder is nearly spherical.