Ti—Al二元粉末机械合金化过程中组织结构的变化

对二元Ti-Al粉末进行机械球磨,结果表明,随着球磨时间的增加,粉末颗粒度初期有明显增加,然后急剧下降,再变缓,最终不再变化;Ti-Al粉末在机械合金化过程中,先形成了枣羔式Ti在Al中的镶嵌,现形成明显的片层结构,随时间延长,片层间距又迅速减小直至Ti/Al界面消失,最终形成非晶,但并无Ti-Al金属间化合物的形成,且随球磨速度的增加片层细化速率加快。

Evolution of Microstructures of Ti/Al Binary Powders During Mechanical Alloying Process

The mechanically milled Ti-Al binary composite powders were observed and analyzed using SEM, EPM and TEM. The experimental results show that with increasing milling time, particle sizes of composite powders remarkably and rapidly increase at first, then greatly decrease, and finally decrease to a constant. The Ti particles form "jujube-cake" in Al powders during mechanical alloying. With increasing time, a obvious lamellar structure forms, lamellar spacing decreases and TiIA1 interfaces disappear, and finally amorphous structure forms. However, the Ti-Al intermetallic compounds did not produce during the whole process.