Abstract: The invention relates to a powder distributor for dosing and conveying a powder up to a use apparatus. The distributor comprises a pressurized storage tank, a dosing vibrating bowl and an Archimedean screw or a valve for transferring the powder from the tank to the bowl. The putting into operation of the screw is controlled as a function of the powder level in the bowl. The vibrating bowl is placed in a tight enclosure into which is injected a carrier gas used for conveying the powder in a pipe up to the use apparatus. An accelerometer carried by the vibrating bowl makes it possible to check the weight of the powder supplied by the latter. Application more particularly to hot spray guns, such as chemical flame torches and quenches arc plasma torch guns, in a free or controlled atmosphere.

Abstract: A metal coating is deposited on a metal substrate by means of a method which consists in sand-blasting the metal substrate, in heating the substrate to a temperature between 100.degree. and 650.degree. C, then in spraying a powder of nickel or cobalt alloy having a high value of hardness and containing reducing agents as well as agents for reducing the melting point, the spraying operation being performed at a distance of 50 to 200 mm from the nozzle of a spray-gun and at a velocity within the range of 100 to 250 meters per second.