The invention discloses a novel hypersonic-speed high-
enthalpy-value
plasma gun and a preparation process of a WC-based
composite coating layer. The novel hypersonic-speed high-
enthalpy-value
plasma gun comprises a
nozzle, a fixed ring, a shell 1, a shell 2, an
integrator, a water dividing sleeve, an
anode, a compressor, a
water cooling sleeve, a spacer sleeve and a
cathode, wherein the compressoris added between the
cathode and the
anode to enlarge the gap between the
cathode and the
anode. The novel hypersonic-speed high-
enthalpy-value
plasma gun and the preparation process disclosed by theinvention have the beneficial effects that the
arc length is prolonged, simultaneously the stability of an arc can be improved, the speed of
flame flow of plasma spraying is increased, and finally, the
flame-flow speed can reach 6-7 Mach (2040-2380m / s); the
coating layer
powder is heated to be in a molten and semi-
molten state in a high-speed
flame, impacts the surface of a workpiece by a high speed, and is deposited to form a dense
coating layer; based on the device and process provided by the invention, the WC-based
coating layer with high deposition efficiency, high
bonding strength, highhardness, low
porosity, high abrasion resistance, high
corrosion resistance and
high wear resistance can be obtained and can be applied on the surfaces of the workpieces such as a
water turbine, a water pump, a
ball valve, a gate and a
piston rod and the like.