The invention provides a supersonic
reactive plasma spray gun, belonging to the
welding field. The spray gun mainly comprises a gun body (1), an insulator (8), a gas swirling ring (11), a
cathode body (6), an in-situ reaction Laval
anode nozzle (12), a fastening sleeve (3), a front fixing cap (16), a back pressing cap (14) and an insulating
gasket (5), which are in the following connection mode that: the in-situ reaction Laval
anode nozzle (12) is connected with the gun body (1) through the front pressing cap (16); the gas swirling ring (11) and the insulator (8) are fixed inside the gun body (1) through the fastening sleeve (3); the fastening sleeve (3) and the gun body (1) are connected through tight fit; the
cathode body (6) is fixed inside the gun body (1) through the insulator (8), the fastening sleeve (3), the back pressing cap (14) and the insulating
gasket (5). The in-situ reaction Laval
anode nozzle (12) is in an integrated structure on which a
powder feeding hole (18), a reaction gas inlet (15), an auxiliary cooling water inlet (18) and an auxiliary cooling
water channel (22) are arranged. The spray gun allows in-situ synthesis and supersonic
plasma spraying to be accomplished in one step, thereby realizing the high performance, high efficiency and low cost of
ceramic coating spraying and the long life-span of the spray gun.