High Temperature Superalloys
Solutions by Application
- Optimize solutions - and prediction of heat treatment.
- Generate artificial microstructures for Finite element analysis.
- Analyze microstructure evolution during high-temperature uniaxial and multiaxial loading.
- Predict creep strain and damage as a function of the thermal and loading history.
During the exposure of turbine blades in intense temperatures and mechanical stresses, single crystal superalloys are the material of choice for its creep resistance properties. Numerous creep deformation mechanisms, active in single crystal superalloys, are implemented in OpenPhase:
- Coherency loss between γ and γ′ phase.
- Accumulative of dislocations around γ′ phase
- Diffusion controlled directional evolution of the micrstructure.
- Coalescence of γ′ precipitates.
- Topological inversion of microstructure.
- Local plastic deformation and shear bands creation
OpenPhase capabilites
OpenPhase is the best software for offering solutions and a deeper understanding of the deformation mechanisms in more depth. Solutions:
- Different heat treatments can be used to produce different sizes of γ′ precipitates.
- By knowing the local misfit and external loads, local stresses can be calculated.
- Directional evolution of microstructure under elastic or elastic-plastic environment.
- Effect of alloying elements on the microstructure evolution and creep properties.
- Non-homogeneous elastic and plastic deformation of superalloys.
- Effect of shear bands on the microstructural evolution.
- Local crystal rotations during creep and plastic deformation.
- Rafting of microstructure leads to the topological inversion.
Microstructure evolution
OpenPhase excels at simulating microstructure evolution under the consideration of various physical effects. In this example, creep in Ni-base superalloys at 950°C and 350 MPa stress is simulated. The microstructure evolution is determined by the interaction of Interface kinetics, Diffusion, Plasticity and Elasticity. All simulated quantities are available at all times in the simulation and yield quantities such as creep curve, phase fraction, element distribution, etc.
The simulation approach is very general and can be transferred to different material systems and processes where phase transformation and/or plasticity are of interest, such as tensile tests or heat treatments.
Mechanical properties
For most metallic materials good mechanical properties are of paramount importance. These properties are determined by the grains, phases, precipitates and defects that make up the microstructure. In nickel-base superalloys gamma- and gamma'-phase form a unique microstructure with gamma' cubes embedded in a gamma matrix. This microstructure evolves during creep deformation and yields outstanding creep properties.
OpenPhase facilitates diffusion, phase transformation, elasticity and plasticity modules to simulate creep deformation in Ni-base superalloys precisely on a microstructural level. Spatial and temporal resolution of all simulated quantities (e.g. plastic strain in figures b and c) enables analysis of microstructural processes. The macroscopic effect of these processes is visualized in the creep curve (figure a).
The simulation approach is very general and can be transferred to different material systems and processes where phase transformation and/or plasticity are of interest, such as tensile tests or heat treatments.
