Thermo mechanical effects on Ti deformation mechanisms in cold dwell

循环载荷是航空发动机部件的特征，它们暴露在低频（例如起飞和着陆）和高频（例如振动）载荷下。因此，了解是什么使钛合金具有疲劳强度是非常重要的，特别是它是如何受到载荷频率和其他环境参数（如温度）的影响的。通过大量的测试，工程师们已经开发出了疲劳强度和不同钛合金微观结构之间良好的经验关系。然而，控制这种行为的实际物理机制尚不完全清楚。这种知识上的差距使得我们很难解释以往经验之外的材料和/或操作条件。这也使得人们很难理解如何改进这种合金，以减少其使用量，从而有助于制造更轻、更高效的航空发动机。该项目的目的是提高我们对这些重要合金在低频循环加载和不同温度下如何在微观结构尺度上变形的理解。与Rolls-Royce合作，您将使用曼彻斯特大学开发的新实验技术，以亚微米的空间分辨率测量这些合金的变形，帮助解开导致疲劳失效和损伤的物理过程，并了解如何避免它们。这项工作将利用曼彻斯特罗伊斯研究所（www.royce.ac.uk）提供的独特的最先进的设备，包括具有原位测试能力的高分辨率电子显微镜，三维晶体定向测绘机器和高分辨率透射电子显微镜。成功的候选人将加入曼彻斯特的一个大型研究团队（10人以上），从事钛合金的研究，并与劳斯莱斯和其他英国和国际大学的科学家和工程师合作。该项目提供了一些目前可用的最先进的表征方法的访问和培训，以及使用开源软件包进行高级数据分析的良好培训。此外，还将有机会参观劳斯莱斯和其他合作伙伴组织。

yclic loading is characteristic of components in an aero-engines, where they are exposed to both low frequency (e.g. take off and landing), and high frequency (e.g vibration) loading. Therefore it is very important to understand what gives Ti alloys their fatigue strength, and in particular how it is affected by the load frequency and by other environmental parameters like temperature. Through extensive testing, engineers have developed sound empirical relationships between fatigue strength and the microstructure of different Ti alloys. However, the actual physical mechanisms controlling this behaviour are not fully understood. This gap in our knowledge makes it difficult to account for material and/or operating conditions outside previous experience. It also makes it difficult to understand how the alloy could be improved, so that less of it can be used, which would help build lighter, more efficient aero-engines. The aim of this project is to improve our understanding of how these important alloys deform at the micro-structural scale during low frequency cyclic loading, and at different temperatures. Working in collaboration with Rolls-Royce, you will use new experimental techniques developed at the University of Manchester to measure the deformation of these alloys with sub-micron spatial resolution, helping to unravel the physical process that lead to fatigue failure and damage and understand how they can be avoided. This work will make use of unique state-of-the-art facilities available at the Royce Institute at Manchester (www.royce.ac.uk), including high-resolution electron microscopes with in-situ testing capability, machines for 3-dimensional crystal orientation mapping, and high resolution transmission electron microscopes. The successful candidate will join a large team of researchers (10+) working on titanium alloys at Manchester, and collaborate with scientists and engineers at Rolls-Royce and other UK and international universities. The project provides access and training on some of the most advanced characterisations methods currently available and sound training in advanced data analysis using open source packages. There will also be opportunities to visit Rolls-Royce and other partner organisations.