Enhanced mechanical properties in a new Ni–Co base superalloy by controlling microstructures

We report the enhanced tensile strength and creep resistance of a new Ni–Co-base superalloy (TMW-2) by increasing the solution temperature from 1100 °C to 1140 °C. The yield strength could be improved by 60 MPa, and a temperature gain in creep resistance of about 15 °C could be achieved. The improvements in yield strength and creep resistance are mainly due to the coarsening of grain size, the increasing of the volume fraction of tertiary γ′ and of the length of annealing twin formed during the heat treatment.

► We examined the tensile and creep properties of a new Ni–Co base superalloy as a function of heat treatment conditions. ► By increasing the solution temperature from 1100 °C to 1140 °C, the yield strength could be improved by 60 MPa, and an improvement of 15 °C in temperature capacity could be achieved. ► The enhanced mechanical properties were mainly ascribed to grain growth, the increasing of fraction of tertiary γ′ and of the length of annealing twin formed during the heat treatment.