Creep behavior of new kinds of Ni–Co-base superalloys

Abstract

This paper concerns our recent work on developing a new kind of advanced disk alloys based on the mixtures of two kinds of two-phase superalloys, Co-base Co-16.9 wt.%Ti and Ni-base U720Li superalloys, for the latest turbine design. The tensile creep behavior of these new Ni–Co-base superalloys at temperatures in the range of 650–760 °C and at initial applied stresses of 480–830 MPa were investigated. Comparing a new Ni–Co-base alloy (TMW-4) to U720Li by a Larson–Miller plot shows that a temperature gain in stress-rupture strength of 30 can be expected in a TMW alloy with fine-grained microstructure (10 (m).