CONTROLLED THERMAL COATING

The process comprises heating, fusing and/or melting a material of stream using a plasma or a flame, measuring, determining and controlling velocity of the material stream, flow rate of gas, brightness distribution or temperature distribution of the material stream and voltage between an electrode and a nozzle and/or a power of the nozzle, changing the current between the nozzle and the electrode and flow rate of the stream as controlled variables, and increasing or decreasing the current. The process comprises heating, fusing and/or melting a material of stream using a plasma or a flame, measuring, determining and controlling velocity of the material stream, flow rate of gas, brightness distribution or temperature distribution of the material flow and voltage between an electrode and a nozzle and/or a power of the nozzle, changing the current between the nozzle and the electrode and flow rate of the stream as controlled variables, and increasing or decreasing the current. The brightness distribution, temperature distribution of the material flow, voltage between the electrode and nozzle and/or the power of the nozzle is maintained as constant. The flow rate of primary and secondary gases is increased or decreased. The method further comprises maintaining controlled variables at desired target values, adjusting parameter sets for different situations including higher, lower or constant the control variables, and determining changes of the target values before coating the material. The coating is carried out by a high velocity oxygen fuel spraying method and a plasma spraying method.