ISSN: 2320-5407 Int. J. Adv. Res. 9(07), 954-969 954 Journal Homepage: - www.journalijar.com Article DOI: 10.21474/IJAR01/13198 DOI URL: http://dx.doi.org/10.21474/IJAR01/13198 RESEARCH ARTICLE EFFECT OF HOT CORROSION AND OXIDATION ON COBALT –BASE SUPERALLOYS COATED BY ALUMINUM WITH PRESENCE OF THERMAL BARRIER ZRO 2 AND MIXTURE OF (NACL) AND (NA 2 SO 4 ) STEAMSALTSAT HIGH TEMPERATURES Khudhur A. Saleh, Mahmood A. Hamood and Nawfal Y. Jahmeel Department of Physics College of Science University of Mosul. …………………………………………………………………………………………………….... Manuscript Info Abstract ……………………. ……………………………………………………………… Manuscript History Received: 25 May 2021 Final Accepted: 29 June 2021 Published: July 2021 Key words:- Aluminum Coating, Thermal Barrier Coating, Diffusion Coating, Oxidation, Hot Corrosion, Cobalt Base Superalloy FSX-414, Protective Coating The aim of the study was to investigate the Mechanisms properties of thermal barrier coatings (TBCs) to enhance of performance evaluation characteristics and develop TBCs.Cobalt –base superalloy has been used as a substrate and zirconium stabilized Aluminum as ceramic topcoat , in addition the study include degradation behavior of system during thermal cycling (3hr per cycle in furnace) the failure of the aluminized was due to thermally grown oxide (TGO) interface. The fractures propagatethrough the interface and produce a deformation of the bond coating . the effect of cycle will result a spallation failure of the TBCsand this is also corresponding to a slightdegradation .The steam of salt (Nacl)and(Na 2 So 4 ) mixture will affecton the coating lifetimes .The high temperature have a strong effect thermally grown oxide (TGO) which consistent with a first order growth of scale failer variation. Copy Right, IJAR, 2021,. All rights reserved. …………………………………………………………………………………………………….... Introduction:- Oxidation and hot corrosion is a problem in power generation equipment, turbines engine for airplane ,rocket and ships and in other energy such as chemical processes system . oxidation and hot corrosion another poses asevere problem as the use of low –grade fuels and due to depletion of high –grade fuels as well as high cost in removing the impurities . coating are frequently applied on gas turbine components in order to restrict surface degradation such as oxidation , hot corrosion of the structural material and to thermally insulate against the hot environment there by increasing the turbine efficiency. surface degradation takes place during hot corrosion, oxidation and solid particle erosion [1][14-17]. Oxidation and hot corrosion may pitting the surface, for example act as crack fatigue leading to failure of the component . in combination with other sub-surface damage processes ,which decrease the strength and ductility this lead to faster failure . oxidation and hot corrosion wasshowed in figure(l),where uncoated gas turbine blades removed and replaced after 2500hr sea flight. Corresponding Author:- Khudhur A. Saleh Address:- Department of Physics College of Science University of Mosul.