Modeling of annihilation of micropores in single-crystal nickel-base superalloys during hot isostatic pressing

• Applicants: Privatdozent Dr.-Ing. Alexander Epishin; Dr.-Ing. Bernard Fedelich
• Subject Area: Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 280132084

High-pressure turbine blades are critical components of aircraft engines. They are cast as single-crystals of nickel-base superalloys. A negative side-effect are casting micropores initiating fatigue failure. The pores can be removed by hot isostatic pressing (HIP), however this technological process, performed at temperature close to solidus, can damage a costly blade by recrystallization and incipient melting. The objective of our project is to develop a computational HIP model for the simulation of micropore annihilation, enabling to optimize the HIP parameters. The target property is blade material without pores with fatigue life increased by many times. Pore annihilation in single-crystals at an ultrahigh homologous temperature of about 0.97 is a complex multiscale physical process. Therefore the computational HIP model will be composed of several physical and phenomenological models considering phenomena from the atomic level up to the continuum level.

• DFG Programme: Research Grants
• International Connection: France
• Co-Investigators: Dr. Yann Le Bouar; Professor Bernard Viguier