Method for obtaining thermal diffusion coating

An apparatus for obtaining thermal diffusion coating on the outside surface of articles of manufacture, wherein the articles are heated within a closed tubular container, said articles are embedded in a powder mixture, containing a specie, capable upon heating to diffuse within the articles surface, said apparatus comprises:

• a) thermal treatment chamber suitable for placing thereinto of at least one container with the said articles and heating thereof up to the temperature sufficient to initiate and maintain the said diffusion, said thermal treatment chamber is configured as a tunnel defined by parallel lateral walls, by a bottom and by a ceiling, the interior of said tunnel is provided with a heating zone heated by heating means, said chamber is closed at one end thereof by an inlet door and at the opposite end thereof by an outlet door,
• b) advancement means, capable to continuously advance the container along the transportation path so as to bring it within the tunnel, to advance it along the tunnel and to evacuate it from the tunnel,
• c) at least one stopper means situated in a discrete position along the transportation path, said stopper means are capable to intermittently prevent the advancement of the container along the transportation path and to cause rotation thereof about its longitudinal axis once the container approached the stopper means
• d) a source of energy for energizing the heating means
• e) appropriate control and instrumentation means for controlling the power supply and the other components so as to carry out the required heating schedule.