Synthesis of Co 3 W–Cu composite nanopowders by mechanical milling and hydrogen reduction process

In this research, synthesis of Co₃W–Cu composite nanopowders based on Co₃W intermetallic compound by mechanical milling and hydrogen reduction process was investigated. Powder mixture of Co₃O₄, WC and CuO with Co₅₀W₄₀Cu₁₀ stoichiometry was first milled by high energy planetary ball mill and then reduced in a hydrogen reduction system. Crystallite structure of milled mixture and reduced powders was determined by X-ray diffraction. Particles size, morphology and cross-section of reduced samples were studied by SEM, TEM and SEM back scattered electron microscopy. Optimum condition of reduction under hydrogen atmosphere was found at 900°C. Particles have Cu coring structure surrounded with Co₃W intermetallic compound. Mean particle size was observed less than 50 nm with six fold hexagon morphology.