Study-on mechanical alloying and subsequent heat treatment of the Ti-Si system

Elemental powder mixtures of TixSi100-x were mechanically alloyed by using a planetary ball mill. XRD, SEM, TEM and DTA were used to characterize thei r mechanical alloying process. After milling for 45 h, Ti75Si25, Ti62.5Si37 .5 and Ti50Si50 powders were amorphized completely; however, no obvious amo rphization was observed for Ti33.3Si66.7 and Ti25Si75 powders. By using Mie dema model, a thermodynamics analysis was performed. Annealing the as-mille d powders in vacuum at 860 degrees C for 1 h, the as-milled Ti62.5Si37.5 po wders transformed into Ti5Si3 intermetallics, and Ti33.3Si66.7 transformed into TiSi2 intermetallics completely. (C) 2000 Elsevier Science B.V. All ri ghts reserved.