Hardfacing Containing Tungsten Carbide Particles with Barrier Coating and Methods of Making the Same

摘要

A hardfacing composition comprising tungsten carbide particles having a barrier coating and a binder alloy is disclosed. The tungsten carbide particles comprise at least one kind of cast tungsten carbide, carburized tungsten carbide, macro-crystalline tungsten carbide, or sintered tungsten carbide. The barrier coating comprises at least one of metallic carbides, borides, nitrides, or their hybrid compounds. The hardfacing composition takes one of the forms selected from a welding/brazing tube, rod, rope, powder, paste, slurry, or cloth, which are suitable for being applied by various welding or brazing methods. The barrier coating would prevent or mitigate the degradation of the tungsten carbide particles due to attack of a molten binder alloy during a welding or brazing process. One of thermoreactive deposition/diffusion methods—halide activated pack cementation for making tungsten carbide particles having a barrier coating is disclosed.