Investigation on material degradation during tip-rub events

在现代航空发动机中，最大限度地减少叶尖和机壳之间的间隙对于提高效率(通过降低燃油消耗)很重要。外壳中的牺牲材料提供了一种“软”材料，以防发生入侵。这类事件会导致产生热量和复杂的多轴应力状态(离心力和摩擦力的组合)，这可能会导致叶片和衬里材料的磨损和微观结构变化形式的退化，从而降低承受使用载荷和温度的能力，或任何未来的入侵事件。拟议的工作将通过实验和模拟两种方法提供对侵入事件对叶片尖端和衬里材料的微观结构和机械性能的影响的基本了解，并将有助于评估对剩余寿命和未来行为的影响，从而改进入侵事件的设计和寿命规则。

Minimising the clearance between the blade tip and casing is important in modern aeroengines to improve efficiency (by reducing fuel consumption). The inclusion of sacrificial materials in the casing provides a 'soft' material should an incursion occur. Such events lead to heat generation and a complex multiaxial stress state (combinations of centrifugal loads and frictional loading), which can result in degradation in the form of wear and microstructural changes in the material of the blade and liner and, therefore, a reduced capability to endure service loads and temperatures, or any future incursion events. The proposed work will provide fundamental understanding through both experimental and modelling approaches, of the effect of incursion events on the microstructural and mechanical properties of the blade tip and liner materials and will assist in assessing the effects on the remaining life and future behaviour, leading to improved design and lifing rules for incursion events.