Preparation of Ni-coated Superfine WC Composite Material

A heterogeneous precipitation method was employed to prepare Ni-coated-WC powders using WC,Ni(NO3)2·6H2O and NH4HCO3 as the raw materials.The coated powders were characterized by SEM,TEM and XRD.An amorphous NiCO3·2Ni(OH)2·2H2O film was uniformly coated on the WC particle surface.After calcined at 550 ℃ for 2 h and reduced at 700 ℃ for 2 h in hydrogen atmosphere,NiCO3·2Ni(OH)2·2H2O was converted to Ni.The particle size of Ni-coated WC powders was about 1-2 μm and had good dispersibility.It is suitable for flame spraying process.