Influence of aluminide diffusion coating on the tensile properties of the Ni-base superalloy René 80

Ni-base superalloy René 80 is widely used in manufacturing aircraft turbine blades. The service temperature of this alloy is in the range of 760-982 °C. Although this alloy possesses suitable mechanical, oxidation and hot corrosion properties, it is coated in order to increase its wear, oxidation, erosion and hot corrosion properties against harmful environmental service conditions.In this paper the influence of applying diffusion coating (CODEP-B) on the tensile properties of René 80 has been studied in the temperature range of 22-982 °C. Experimental results show that the tensile properties of the coated specimens are relatively lower than that of uncoated ones in the same conditions. But in the service conditions, coating could have some useful and positive effects practically.In aircraft turbines in service conditions, the maximum strain the blades experience is always bellow 1% and in this range of strain no crack initiates and generates on the applied coating surface. Thus in this situation, the coating would certainly have protective properties preventing from oxidation, hot corrosion and erosion of the base metal.