Composite Powder Products for Hardmetals

A composite powder product comprising a hard particulate phase coated with cobalt or nickel, or a mixture of cobalt and nickel, wherein the hard particulate phase has a particle size between 0.1 and 10 μm.

A hardmetal comprising a sintered composite powder product, the composite powder product comprising a hard particulate phase coated with cobalt or nickel, or a mixture of cobalt and nickel, wherein the hard particulate phase has a particle size between 0.1 and 10 μm.

A tungsten carbide product coated with a metal phase selected from cobalt, nickel or a nickel-cobalt alloy, prepared by the method of:

• feeding tungsten carbide powder having a particle size of 0.1-10 μL, together with either one or both of a cobalt sulphate and a nickel sulphate solution, and ammonium hydroxide, to an autoclave;
• and
• precipitating the metal phase onto the tungsten carbide powder surface by reacting the cobalt and/or nickel ions with hydrogen, thereby obtaining a coated tungsten carbide slurry, and washing, filtering, and drying said tungsten carbide slurry.

A process for preparing a composite powder product comprising the steps of:

• feeding tungsten carbide powder having a particle size of 0.1-8 μm, together with either one or both of a cobalt sulphate and a nickel sulphate solution, and ammonium hydroxide, to an autoclave;
• and
• precipitating a metal phase onto the tungsten carbide powder surface by reacting the cobalt and/or nickel ions with hydrogen, thereby obtaining a coated tungsten carbide slurry, and washing, filtering, and drying said tungsten carbide slurry.