Preparation of Ti-Si Amorphous Powders and their Shock Consolidation

Abstract

Ti-Si powder mixtures were milled in a low energy rotational ball mill under Ar atmosphere, and the milled powders were dynamically compacted by using a propellant gun. During milling of Ti_100-XSi_X powder mixtures containing 20-50 at.%Si, the α-Ti and Si phases were progressively refined to average grain sizes of 20-30 nm in diameter and subsequently, the structure was amorphized. By dynamically compacting the amorphous Ti₅₀Si₅₀ powder at a shock pressure of 32.6 GPa, a partially crystallized amorphous alloy having an extremely high hardness (Hv??1300) was obtained. By annealing the materials at 1023K for 1h, crystallization and grain growth occurred to about 15-20 nm, and the hardness was increased to a maximum value (Hv??1700).