An Experimental and Modelling Approach to Engineering the Stability of Mixed Micro- and Nano-Grain Size Polycrystals to Improve Durability

本研究计划的重点是了解和控制所选fcc， bcc和hcp金属和合金的微纳米状态下异常双峰晶粒尺寸组织的断裂过程。先前的研究表明，在纳米级晶粒基体中，由于晶粒生长异常而产生的粗晶粒提高了延展性，而且强度损失很小。因此，值得进行这些混合晶粒分布如何影响变形和抗断裂性的新努力。该研究策略的一个关键特征是，它建立在一个经过验证的多学科方法的基础上，涉及一个由四个大学小组组成的研究联盟，这些大学小组在与材料性能相关的一系列主题方面拥有各自的专业知识。通过共同努力，我们的技能得到了提高，并获得了EPSRC之前两项资助。该项目的目标将通过一个实验项目来实现，包括设计和描述条件，以实现所需的跨越微到纳米长度尺度的异常生长，模拟晶粒生长/断裂过程，测量变形和异常混合晶粒尺寸材料的抗断裂性。定期的会议和交流将确保项目受益于团队内部的协同作用。该项目得到了Integran技术公司和英国能源有限公司的热情支持（见所附的支持信）。

The focus of this research proposal is to understand and control fracture processes in anomalous bimodal grain sized microstructures in the micro to nano regime of selected fcc, bcc and hcp metals and alloys. The idea has been stimulated by previous work which showed that coarse grains arising from anomalous grain growth in a nanoscale grain matrix improved ductility with little strength-loss penalty. It is therefore worthwhile to pursue the novel endeavour of how these mixed grain distributions could influence deformation and fracture resistance. A key feature of the research strategy is that it is founded on a proven multidisciplinary approach involving a research consortium of four university groups who have individual expertise in a range of topics related to material performance. Working together has resulted in an enhanced skill set, endorsed by two previous EPSRC grants to the group.The aims of the project will be achieved by an experimental programme involving designing and characterising conditions to achieve the required anomalous growth spanning the micro to nano length scales, modelling the grain growth/fracture process, measuring the deformation and the fracture resistance of the anomalous mixed grain size materials. Regular meetings and interchange will ensure that the project benefits from the synergy within the group. The project has the enthusiastic backing of Integran Technologies Inc and British Energy Ltd (see appended letter of support).