초록 ▼

A process and apparatus for surface coating of workpieces in fluidized beds under atmospheric or slightly higher pressure is disclosed. The process comprises submerging the workpiece(s) in the fluidized bed, mixing a metal halide with an inert gas to form the fluidizing gas, feeding to the fluidized

A process and apparatus for surface coating of workpieces in fluidized beds under atmospheric or slightly higher pressure is disclosed. The process comprises submerging the workpiece(s) in the fluidized bed, mixing a metal halide with an inert gas to form the fluidizing gas, feeding to the fluidized bed another gas which is capable of reacting with the metal halide in the fluidized bed and coating the workpiece(s). The workpiece(s) are maintained at a temperature in the range of from 1600°F. to 2000°F. until it is evenly coated. The apparatus comprises a saturator vessel for saturating the inert gas with the metal halide and a fluid bed reactor. There are several advantages that the present invention offers over the prior art, namely, the coating can be performed in a relatively short period of time, 4 to 5 hours and that atmospheric pressure can be used, eliminating the need for a costly vacuum system.

대표청구항 ▼

A process of surface coating a metal workpiece in a short period of time under substantially atmospheric pressure comprising: a. fluidizing a bed of inert particulate matter; b. submerging the workpiece in the fluidizied bed; c. heating the submerged workpiece in the fluidized bed to a predetermined

A process of surface coating a metal workpiece in a short period of time under substantially atmospheric pressure comprising: a. fluidizing a bed of inert particulate matter; b. submerging the workpiece in the fluidizied bed; c. heating the submerged workpiece in the fluidized bed to a predetermined temperature; d. fluidizing the bed with an inert gas in which a metal halide has been mixed; e. feeding a gas capable of forming a nitride, a sulfide, a carbide or an oxide with the metal of the metal halide and depositing the nitride, sulfide, carbide or oxide on the surface of the workpiece; f. maintaining the bed at the elevated temperature and slightly greater than atmospheric pressure for a period sufficient to coat the workpiece and provide a metallurgical bond between the coating and the workpiece; g. cooling the coated workpiece.