机械合金化钛、锡、碳混合粉体中锡晶须的形成机理

Formation Mechanism of Sn Whiskers in Mechanical Alloying Mixed Powder of Ti,Sn,C

将质量比为2…1…1的钛粉、锡粉和碳粉混合,在高能球磨机中进行机械合金化,再进行室温时效处理,研究了机械合金化粉体中锡晶须的物相组成、微观结构及形成机理。结果表明:经机械合金化和室温时效处理后,混合粉体中出现絮状物,絮状物由锡晶须组成;锡晶须为体心正方结构β-Sn单晶体,呈柱状、丘状或结节状、纽结或弯折状和针状,直径约为100 nm,晶带轴为β-Sn的[011]晶带轴;在机械合金化产生的热量和巨大应力作用下,锡发生再结晶定向生长形成锡晶须。

The mixture of Ti powder,Sn powder and C powder with mass ratio of 2…1…1 was mechanically alloyed in a simoloyer mill,and then was treated by aging at room temperature.The phase composition,microstructure and formation mechanism of Sn whiskers in the mechanical alloying powder were studied.The results show that flocs appeared in the power mixture after mechanical alloying and aging at room temperature,and were composed of Sn whiskers.The Sn whiskers were columnar,collicular-shaped or nodular,knotted or curved,and needle-shaped single crystal β-Sn with body centered tetragonal structure.The whisker had a diameter of about 100 nm,and the zone axis was [011] zone axis of β-Sn.Under heat and huge stresses produced by mechanical alloying,the recrystallization and direct growth of Sn occurred,and then Sn whiskers were obtained.