Plasma Welding Introduction

the essence of the method

detailed illustration of plasma welding

plasma - an ionized gas containing electrically charged particles and capable of conducting current.

Ionization of the gas occurs when heated. The degree of ionization is higher, the higher the temperature of the gas. In the central part of the arc gas is heated to temperatures 5000-30000 ° C, has a high electrical conductivity, brightly lit and is a typical plasma. Plasma jet is used for welding and cutting, receive special plasmatrons in which heat the gas and its ionization arc discharge performed in special chambers.

1 - tungsten electrode - cathode, 2 - channel of the nozzle, 3 - arc column 4 - the flow of plasma

Injected into the gas chamber, compressing the arc column in the channel of plasmatron nozzle and cooling of its surface layers, increases the temperature of the column. As a result, the jet passes the gas is heated to high temperatures, is ionized and becomes plasma properties. The increase in heating the gas volume in the 50-100 and over again leads to the expiration of the plasma at supersonic speeds. The plasma jet is easy to melt any metal.

Arc plasma jet welding and cutting are the two main schemes. When the plasma jet direct product included in the welding arc circuit, the active spots which are located on a tungsten electrode and the workpiece. When the plasma jet indirect active arc spots are on a tungsten electrode and the inner surface or side of the nozzle. Plasma-forming gas can also serve as protection of the molten metal from the air. In some cases, to protect the flow of molten metal using a single jet of a special, less expensive shielding gas. The gas moving along the walls of the nozzle is less ionized and has a lower temperature. Because of this prevented the melting of the nozzle. However, most plasma torches has an additional water cooling.

Arc plasma jet - an intense heat source with a wide range of technological properties. It can be used for heating, welding or cutting a conductive metals and nonconductive materials such as glass, ceramics, etc. (plasma jet of the indirect effect). Thermal efficiency of arc plasma jet depends on the welding current and voltage, composition, flow rate and velocity of the plasma gas, the distance from the nozzle to the workpiece surface, the velocity of the torch (welding or cutting speed), etc. The geometric shape of the jet may also be different (square, round, etc.) and form determined by the nozzle outlet openings.

See also:
Plasma Welding
Plasma Welding Introduction
Plasma Welding Technique
Microplasma Welding
Gases for plasma processing of materials
Separation of plasma jet cutting
Compression of the arc
The energy properties of the plasma arc
Rationalization of plasma welding
Plasma welding and spraying
The plasma melting and remelting
Plasmatron. Requirements for plasmatron
Plasmatron. Schemes, classification
Classification by type of electrode plasma torches
Classification of torches by the nature of the current
Structure of the plasmatron basic units