چكيده به لاتين
Nickel-based superalloys used in high operating temperature applications, in addition to these superalloys have good resistance to corrosion and oxidation and high resistance to creep and failure at high temperatures. Aluminide coatings have been widely used for many years to resist oxidation to components in turbine engines made of Nickland-based superalloys because they improve their properties and increase the strength of superalloys. These aluminide coatings are applied to superalloys by various methods, which we examined in this project is gas method. In this project, we first examined the amount of weight of the coating powder and its amount was (20, 30, 35, 40, 100) grams, which was the optimal state of 35 grams. And we examined the composition of the coating powder, which is the ratio of powder (aluminum, NH4Cl activator, and AL2O3), respectively. Powder composition ((36-6-58) (30-5-65) (24-4-72) (18, 3, 79) and (12, 4, 84) and etc) which is the most optimal case in this case (18, 3; 79). In this coating, we used a furnace with two thermal zones, the sample is at a temperature of 1200 ° C and the powder coating is at a temperature of 750 ° C, and the sample is covered for 4 hours at this temperature, then the furnace is turned off. Let the sample cool slowly. After coating, we prepare the sample and examine elemental analysis, Phase analysis and microstructural analysis, which in the best case is a coating thickness of 35 microns and a two-layer coating, the middle layer is the penetration layer. Studies have shown that the higher the amount of powder, does not mean that the thickness of the coating increases, and in addition to the thickness, the coating also depends on the shape and morphology of the coating, which is the better the properties of the coating.
