Method for thermal spray deposition of a coating on a surface and apparatus

A thermal spray deposition torch comprising

• a main body having an elongated shape developing around a longitudinal axis, and provided, at one end of the main body, of a spray head and at least one dispensing nozzle configured to create a jet of a material to be deposited on a surface of a workpiece to be coated, the thermal spray deposition torch being configured to be controlled by a robot and comprising a coupling system configured to join the thermal spray deposition torch, at the other end of the main body, to a supporting arm of the robot, said thermal spray deposition torch comprising a motor configured to rotate the at least one dispensing nozzle with respect to the main body or configured to rotate said main body, the thermal spray deposition torch being further configured so as to create two concurrent movements to the jet of the material to be deposited, of which:
• a first movement along an area of the surface of the workpiece to be coated and in a direction corresponding to said longitudinal axis, defining a linear path for said jet, said first movement being carried out by linear advancement of said thermal spray deposition torch, and
• a second movement of oscillation according to a plane which is transversal to said longitudinal axis, said second movement being carried out by rotating said at least one dispensing nozzle back and forth about said longitudinal axis with respect to said coupling system by the motor,
• wherein, the thermal spray deposition torch is configured such that during the second movement, the at least one dispensing nozzle oscillates back and forth continuously while the thermal spray deposition torch concurrently advances along the linear path for said jet according to the first movement.

An apparatus for depositing a coating on a surface of a workpiece comprising

• a robot including a supporting arm and motor configured to rotate said supporting arm, the apparatus further comprising a thermal spray deposition torch including a main body having an elongated shape developing around a longitudinal axis, and is provided, at one end of the main body, of a spray head and at least one dispensing nozzle configured to create a jet of a material to be deposited on the surface of the workpiece to be coated, the thermal spray deposition torch being configured to be controlled by the robot and comprising a coupling system configured to join the thermal spray deposition torch, at the other end of the main body, to the supporting arm of the robot, the apparatus being configured so as to move the thermal spray deposition torch according to two concurrent movements and create the jet of the material to be deposited moving along said two concurrent movements, of which:
• a first movement along an area of the surface of the workpiece to be coated and in a direction corresponding to said longitudinal axis, defining a linear path for said jet, said first movement being carried out by linear advancement of said robot with said thermal spray deposition torch joined to said supporting arm, and
• a second movement of oscillation according to a plane which is transversal to said longitudinal axis, said second movement being carried out by rotating said at least one dispensing nozzle back and forth about said longitudinal axis with respect to said coupling system and by the motor,
• wherein, the thermal spray deposition torch is configured such that during the second movement, the at least one dispensing nozzle oscillates back and forth continuously while the thermal spray deposition torch concurrently advances along the linear path for said jet according to the first movement.