| 摘要 |
In a process for the simultaneous deposition of a protective coating, e.g. an aluminuim based coating, on internal and external surfaces of heat-resistant alloy parts, the parts are placed in a box containing a donor material, preferably in the form of granules, comprising the metal to be deposited, and an activator separate from the donor and comprising at least an anhydrous powder of chromium fluoride CrF3 to provide a source of fluorine. The box is heated to a temperature above 1000 DEG C. and a controlled flow of a carrier gas, reducing or neutral, is introduced into the box so as to establish a circulation of gases in the box whereby fluorinated vapors from thermal decomposition of the CrF3 activator contact the donor to form a volatile fluoride of the metal to be deposited, and the volatile vapor is carried into contact with the external and internal surfaces of the parts to be coated to deposit the coating thereon.
|
