Advanced Powder Technology, Vol.30, No.10, 2311-2319, 2019
Preparation of Co-plated WC powders by a non-precious-Co-activation triggered electroless plating strategy
In this study, Co nanoparticles were mixed with WC powders by electroless plating with a new nonprecious-Co-activation strategy. By soaking WC powders in a mixed solution of cobalt sulfate heptahydrate and sodium hypophosphite and then heat treated at 220 degrees C, Co active sites were seeded on WC powders to activate the following electroless plating of Co. The effects of reaction conditions on the weight gain and plating rate during electroless plating process were systematically investigated. As is evidenced by results, when the temperature, concentration of CoSO4 and NaH2PO2 center dot H2O, and pH were 80 degrees C, 50 g/L, 45 g/L and 11 respectively, WC was evenly coated with Co. Notably, the XPS characterization indicated the content of zero-valence Co was elevated obviously after the plating process due to the effective reduction from two-valence Co. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.