Synthesis of amorphous/crystalline composite using electroless copper plated amorphous powder

Abstract

An amorphous/crystalline composite was synthesized by warm extrusion of copper-deposited Ni57Zr20Ti18Si3Sn2, amorphous powder. Electroless plating method was applied to deposit crystalline copper on Ni57Zr20Ti18Si3Sn2 amorphous powder after fabricating Ni57Zr20Ti18Si3Sn2 amorphous powder by gas-atomization technique. Fully amorphous Ni57Zr20Ti18Si3Sn2, powder with a supercooled liquid region of 58 K could be obtained in the particle size range below 75 mu m. Uniform deposition of crystalline copper on the Ni57Zr20Ti18Si3Sn2 amorphous powders was successfully performed by electroless plating. The optimum processing conditions for extrusion were obtained from the time-temperature-transformation curve determined by isothermal annealing of Ni57Zr20Ti18Si3Sn2 amorphous powder. The extruded amorphous/crystalline composite shows plasticity after yielding and exhibits a strength level of 1.3 GPa and plastic stain of about 3% under compressive condition. While monolithic bulk Ni57Zr20Ti18Si3Sn2 amorphous alloy fabricated under same extrusion condition shows no plastic deformation. (c) 2005 Elsevier B.V. All rights reserved.