Dynamic mechanical properties of plasma sprayed Ni-based alloys

This paper describes the use of dynamic mechanical analyzer techniques to measure the temperature dependence of the dynamic mechanical properties of Nickel-based bond coats: NiAl, NiCrAlY, and NiCoCrAlY in the temperature range 30-950°C. The experimental measurements revealed that the brittle-to-ductile transition process for α-Ni is governed by the diffusion of nickel atom with an activation energy of Q=207.7 kJ/mol. NiCrAlY bond coat displayed the lowest modulus at all temperature investigated. The drop in modulus at about 600°C was attributed to the resolution of γ′ to γ with activation energy of Q=241.7 kJ/mol. The NiCoCrAlY bond coat displayed an excellent storage modulus at all temperatures. The addition of cobalt has improved the γ′ to γ resolution temperature. The process's kinetic activation energy was measured to be Q=279.9 kJ/mol.