Experimental and modelling methodologies for fatigue crack nucleation around non-metallic inclusions in polycrystalline Ni-base superalloy.

粉末冶金已成为生产镍高温合金涡轮盘的首选方法。粉末冶金的一个不可避免的副作用是倾向于在镍基中包含非金属团聚。这些夹杂物可能会产生局部活动应力场，从而驱动裂纹的形核。最近的研究对室温下裂纹形核的不同标准进行了研究。某型喷气发动机涡轮的实际工作环境是高温的，在这种环境下裂纹的形核还有待进一步研究。该项目旨在通过使用实验和建模技术来研究高温条件下夹杂周围出现裂纹的标准。

Powder metallurgy has become the preferred method for producing nickel-superalloy turbine disks. An unavoidable side-effect of powder metallurgy is the propensity to include non-metallic agglomerates in the nickel matrix. These inclusions may create a locally active stress field that may drive the nucleation of cracks. Recent studies have investigated different criteria for crack nucleation at room temperature. The real working conditions of a jet engine turbine are at high temperature and work remains to be done on crack nucleation in such an environment. This project aims to investigate the criteria for which cracks appear around an inclusion subject to high-temperature conditions by using experimental and modelling techniques.