Synthesis and characterization of nanocrystalline CoTi intermetallic compound prepared by mechanical alloying

摘要

In the present investigation, the nanocrystalline CoTi intermetallic compound was synthesized by mechanical alloying (MA) of the elemental powders. In all MA runs, the ball-to-powder weight ratio was 5:1. The phase evo-lution and microstructural changes of the powders during mechanical alloying were investigated by means of X-ray diffractometry, scanning electron microscopy, high-resolution transmission electron microscopy and microhardness measurements. The results showed that after an optimum mechanical alloying time of 30 h, a CoTi intermetallic phase with the crystallite size of less than 10 nm, the particle size of about 10 urn and the lattice strain of 0.6% was achieved. The nanocrystalline CoTi intermetallic compound exhibited high micro-hardness value of about 480 Hv.