Crystallization of Cu50Ti50and Cu66Ti34metallic glasses

Abstract

Detailed studies of the crystallization behaviour of the melt-spun Cu₅₀Ti₅₀ and Cu₆₆ Ti₃₄ metallic glasses have been made by differential thermal analysis, X-ray diffraction and microhardness measurements. The samples were isochronally annealed from room temperature up to 1200 K. It was found that crystallization occurs at ∼ 700 K for both glasses, and that for Cu₅₀Ti₅₀ this involves the appearance of tetragonal CuTi and Cu₄ Ti₃ phases, while for Cu₆₆Ti₃₄ it involves the formation of the tetragonal Cu₃Ti₂ phase and orthorhombic Cu₂Ti and β′'-Cu₃ Ti phases. Crystallization products of both glasses showed strong preferred orientation, as evidenced by X-ray diffraction. The structural changes on annealing may be correlated with changes observed in the microhardness of the annealed samples.