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

Abstract

An amorphous/crystalline composite was synthesized by warm extrusion of copper-deposited Ni 57Zr 20Ti 18Si 3Sn 2 amorphous powder. Electroless plating method was applied to deposit crystalline copper on Ni 57Zr 20Ti 18Si 3Sn 2 amorphous powder after fabricating Ni 57Zr 20Ti 18Si 3Sn 2 amorphous powder by gas-atomization technique. Fully amorphous Ni 57Zr 20Ti 18Si 3Sn 2 powder with a supercooled liquid region of 58 K could be obtained in the particle size range below 75 μm. Uniform deposition of crystalline copper on the Ni 57Zr 20Ti 18Si 3Sn 2 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 Ni 57Zr 20Ti 18Si 3Sn 2 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 Ni 57Zr 20Ti 18Si 3Sn 2 amorphous alloy fabricated under same extrusion condition shows no plastic deformation.