Measure of the gradient of mechanical properties in MCrAlY coated MC2 Ni-base superalloy system at high temperature
Résumé
Gradient of mechanical properties existing in coated superalloys system has been quantified in the temperature range corresponding to turbine blades operating conditions. Hence, ultrathin tensile specimens (20 to 100μm thick samples) were extracted in the different zones of the gradient of microstructure i.e (coating, superalloy substrate and interdiffusion zone). Specimens were then tested on mechanical test rigs dedicated to specimens with micrometric thicknesses. Results concerning the mechanical behavior of the interdiffusion zone led to conclude that this zone of the microstructural gradient had to be considered as a non bearing zone in creep conditions representative of service operating conditions.