Thermal coating of cavity surfaces, especially plasma spray coating of cylinder running surfaces of an i. c. engine crank-case, comprises directing an inert gas stream parallel to the surfaces being coated

摘要

Thermal coating of cavity surfaces, while directing an inert gas stream parallel to the surfaces being coated, is new. Cavity surfaces are thermally coated, using a moving torch flame surrounded by a non-combustible first gas stream, by subjecting an oxidizable coating material to acceleration, heated by the flame and deposition on the surfaces while the cavity is flushed with air, the surfaces to be coated being exposed to a second inert gas (especially nitrogen) stream directed parallel to the surfaces. An Independent claim is also included for equipment for carrying out the above process.