Mechanical alloying and characteristics of spark plasma sintering of Ti-Al composite powders

摘要

The mechanical alloying process of Ti-Al composite powders were carried out by use of high energy ball-milling machine.Structure variations of powder mixtures during mechanical alloying and characteristic of spark plasma sintering were investigated.The results show that during milling,TiAl,Ti3Al and Ti2Al phase intermetallic compounds are formed,simultaneously with powder refinement for the (TiH2-45Al-0.2Si-5Nb) and (TiH2-45Al-0.2Si-7Nb) mixtures.The particle sizes of two powder mixtures are less than 300 nm after milling for 30 h.Sintering process of the milled powder can be completed in a short time by spark plasma sintering,and the sintering microstructure is composed of fine and homogeneous TiAl and Ti3Al phase.