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

高压涡轮机叶片是航空发动机的关键部件。它们被铸造成镍基高温合金的单晶体。一个负面的副作用是铸造微孔引发疲劳失效。气孔可以通过热等静压（HIP）去除，然而，在接近固相线的温度下进行的该技术过程可能通过重结晶和初期熔化而损坏昂贵的叶片。我们的项目的目标是开发一个计算HIP模型，用于模拟电子湮没，从而优化HIP参数。目标性能是叶片材料无气孔，疲劳寿命提高数倍。在单晶体中，在0.97 ℃左右的同系温度下的孔湮灭是一个复杂的多尺度物理过程。因此，计算HIP模型将由几个物理和唯象模型，考虑从原子水平到连续水平的现象。

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.