Creep-fatigue strength of a Ni-base single crystal superalloy.

Fatigue-creep-environment Interactions in a Directionally-solidified Ni-base Superalloy

Directionally-solidified (DS) GTD-111 is a Ni-base superalloy designed to withstand damage occurring in the first and second stage blades of gas-powered turbines. Because of the distinctive microstructure of this material, the manner in which fatiguecreep-environment damage mechanisms interact to initiate cracks is sensitive to grain structure and chemical composition. Along with fatigue cyclin...

Creep Crack Growth Simulation of Ni-base Superalloy

The purpose of this study is to develop a numerical approach to simulate the creep cracking of a Ni-base superalloy. The approach is based in continuum damage mechanics (CDM) and uses the classic Kachanov-Rabotnov constitutive equations for creep deformation and damage evolution. Creep damage takes the form of defects such as microcracks, cavities, voids, etc. A numerical crack growth algorithm...

Thermomechanical Fatigue Behavior of a Directionally Solidified Ni-Base Superalloy

A continuum crystal plasticity model is used to simulate the material behavior of a directionally solidified Ni-base superalloy, DS GTD-111, in the longitudinal and transverse orientations. Isothermal uniaxial fatigue tests with hold times and creep tests are conducted at temperatures ranging from room temperature (RT) to 1038°C to characterize the deformation response. The constitutive model i...

Creep and Stress Relaxation Anisotropy of a Single-Crystal Superalloy

In- and Out-of Phase Thermomechanical Fatigue of a Ni-Based Single-Crystal Superalloy

In this study, the difference between in-phase (IP) and out-of-phase (OP) thermomechanical fatigue (TMF) cycling from 100 to 750 ◦C has been investigated for the Ni-based single-crystal superalloy MD2. In addition, two different crystal orientations were studied, the 〈001〉 and 〈011〉 orientations respectively. When comparing IP and OP TMF lives, a strain range dependency is found for the 〈001〉 d...