Core-shell structure type tungsten carbide-cobalt hard alloy raw material powder and preparation method thereof

The invention provides a method for preparing core-shell structure type tungsten carbide-cobalt composite powder. Hard phase tungsten carbide in the composition powder is completely and evenly coated by binding phase metal cobalt to form a core-shell structure. The method comprises the steps of: performing ultrasonic dispersion on tungsten carbide powder; then adding the tungsten carbide powder into a cobalt-containing reducing solution; adjusting the pH value of the solution, and controlling the temperature; then adding a reducer solution in a dripping mode; reducing an even cobalt coating layer on the surface of hard phase tungsten carbide powder; and forming the core-shell structure type tungsten carbide-cobalt composite powder. Hard alloy raw material powder obtained by adopting the method has high dispersivity; a hard phase and a binding phase have even distribution so as to ensure that the powder is easy for alloying; and obtained hard alloy has high obdurability.