Effect of shear strain on metal deformation and microstructural evolution

该项目的目的是进行鞋底剪切变形（即，无轴向应变分量），确定剪切应变对变形机制、微观结构和织构演变的影响，并开发新的加工程序，以定制各种结构应用的金属材料的微观结构和织构。这项研究将利用先进的显微镜和在斯旺西，中央中子衍射设施（ISIS，迪科）和晶体塑性有限元建模（CPFEM）的机械测试单元的状态，以开发一个mechanistic understanding.Methodology：具有非常不同的晶体结构，钛，锆和镁（六方晶系），铝（面心立方晶系）和铌的金属被选择用于这项研究，由于其工业相关性。这项研究的开始将集中在实现一个凹槽压力机兼容的CoE加载机执行鞋底剪切变形。对于机械的理解，从不同阶段的变形和再结晶的标本将使用一系列的显微镜设施，光学，SEM，TEM和EBSD，在斯旺西进行分析。Engin-X，ISIS的原位研究将提供不同晶粒族的代表性晶格应变演变的详细信息，并允许深入了解不同变形模式的活动。这些量也可以作为CPFEM的输入，以便更好地理解变形机制。CPFEM还将用于预测织构和晶格应变演化。

The aim of this project is to perform sole shear deformation (i.e., without axial strain components) of metals and determine the effect of shear strain on deformation mechanisms, microstructure and texture evolution and develop novel processing procedures to tailor the microstructure and texture of metallic materials for various structural applications. This research will exploit state of the art advanced microscopy and CoE mechanical testing units in Swansea, the central neutron diffraction facility (ISIS, Didcot) and Crystal plasticity finite element modelling (CPFEM) to develop a mechanistic understanding.Methodology: The metals having very different crystal structures, Ti, Zr and Mg (hcp), Al (fcc) and Nb are selected for this research due to their industrial relevance. The start of this research will focus on implementing a Groove Press compatible with the CoE loading machines to perform sole shear deformation. For a mechanistic understanding, specimens from different stages of deformation and recrystallization will be analysed using a range of microscopy facilities, optical, SEM, TEM and EBSD, available in Swansea. In-situ studies at Engin-X, ISIS, will provide details of representative lattice strain evolution of different grain families and allows insights into the activity of different deformation modes. These quantities can also be inputs for CPFEM for better understanding of the deformation mechanisms. CPFEM will also be employed to predict texture and lattice strain evolution.