Production of Aluminium Coating for Gas Turbine Engines By Cementation Method

In this research ,a new pack design has been used for production of metallic coating for alloys, in order to resist oxidation and corrosion at high temperatures. Such alloys are manufactured for some parts of Gas Turbine engines and boilers.
In traditional pack cementation method for production of aluminide coating, a mixture of powders, such as, Aluminium ,Ammonium chloride ,and Alumina were mixed together at a certain percentage, and the parts to be coated are submerged in this mixture, after coating time proceeds, the mixture is usually discarded and can not be used again because the Ammonium chloride which has been dissociated can not be replaced with the same percentage again.
This process could lead to a high loss of unused Aluminium powder.
This new pack design can offers an opportunity to isolate Ammonium chloride (activator) from the rest of pack mixture, by so, one can substitute the activator alone without replacing the rest of mixture.
Such pack design has been used in the investigation of coating production at different temperatures and the structure of the coating produced was compared with that produced in traditional method for the same alloy , and the results were indicated to a good similarity of structure except in thickness.