The invention belongs to the fields of 3D printing additive manufacturing,
metal surface treatment,
welding and
metal surface repair, and specifically relates to a
cathode-free
plasma generator, which is characterized by comprising: a gas dividing ring, a
cathode guide column, a blocking medium, a working power
anode, a working power
cathode, a gas channel, an arc starting stage, an outer shell, an inner shell, a
radio frequency power supply, a
radio frequency power
anode, an insulating pad, a sealing ring, a cathode support and an
anode insulating pad. The invention utilizes a dual power supply
system, one
radio frequency power supply is used for arc starting, and the other is a working power supply. When working, the radio frequency power supply first forms a micro-point halo with the blocking medium, and then the working power supply forms a
plasma arc with the blocking medium, so that the
ablation of the cathode during arc starting is greatly reduced. The blocking medium and the cathode are tightly connected. The anode
plasma arc of the cathode-free
plasma generator involved in the invention is not directly generated with the cathode, and the cathode is basically free of
ablation, which greatly improves the life of the cathode.