Microstructure and mechanical properties of cast Ni-base superalloy K44

The Ni-base superalloy K44, developed recently in China, plays an important role in manufacturing blades of gas turbine engines due to its high temperature capability. The microstructure, deformation mechanism and mechanical properties of the Ni-base superalloy K44 have been investigated. Tensile properties and creep behaviors show abnormal variations with increasing temperatures, and the creep data can be fitted well with modified Dyson–McLean relation. transmission electron microscopy (TEM) observations confirmed that these behaviors are affected by the γ′ properties and the deformation mechanism at high temperature. On the basis of creep test results, Larson–Miller and Monkman–Grant plots for life prediction are made. The fracture characteristics of Ni-base superalloy K44 alloy at different temperatures and stress are also studied.