A composite composition comprising tungsten carbide particles having a barrier coating and a binder is described, which is used as hardfacing materials. The tungsten carbide particles comprise at least one kind of cast tungsten carbide, carburized tungsten carbide, macro-crystalline tungsten carbide and sintered tungsten carbide. The barrier coating comprises at least one of metal carbides, borides, nitrides, carbonitrides, carboborides, nitroborides and carbonitroborides. The binder alloys take one of the forms selected from a welding/brazing tube, rod, rope, powder, paste, slurry and 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.