Microstructure Evolution and Mechanical Behaviour of Advance Structural Materials

强度和延展性等材料性能在很大程度上取决于材料的内部结构（微观结构）。本工作的目的是提供一个更好的理解的过程中，控制先进钢的加工和使用过程中的微观结构演变。最终，这将使我们能够调整加工参数（例如温度和变形），从而生产出具有有利微观结构的材料，从而具有有利的性能。拟议的工作有三个主要重点。第一个是低碳钢的相变领域。众所周知，铁Fe以两种形式存在;高温形式称为奥氏体，低温形式称为铁素体。合金元素的添加已被证明对冷却时从奥氏体到铁素体的转变的动力学具有强烈的影响。尽管这种转变具有重要意义，但合金元素影响转变的机制仍然知之甚少。拟议的工作将涉及高度控制的实验，这将使我们能够更好地了解合金元素的影响。最近在原子尺度的表征领域的突破将被利用，以开发实验验证的相变模型。 ** 第二个感兴趣的领域是热机械加工。对热机械过程如热轧的极大兴趣是由于这样的事实，即这些允许细化微观结构，这反过来又导致强度和韧性的改善。在拟议的工作中，一系列的实验合金将进行研究，以确定热轧过程中发生的微观结构的关键变化。 一旦了解这些变化，将开发基于物理的多道次变形模型，并用于优化加工条件。 ** 作为本提案的一部分，将研究的第三个主题是多个长度尺度的微结构工程。除了微观结构内的固有尺度之外，还可以通过引入成分梯度（毫米量级）或通过引入结构化增强（厘米量级）来引入新尺度。 拟议的工作将探索利用这些长度尺度的潜力，以生产具有新特性组合的材料。总共有10名高素质的个人将在对加拿大工业非常重要的领域接受培训。 毕业生将有资格在钢铁，汽车和制造业工作。

Material properties such as strength and ductility are strongly dependent on the internal structure (microstructure) of the material. The objective of the present work is to provide a better understanding of the processes which control the microstructure evolution during the processing and use of advanced steels. Ultimately, this would permit us to adjust the processing parameters (e.g. temperature and deformation) so as to produce a material with a favourable microstructure and consequently, favourable properties.******The proposed work has three main thrusts. The first of these is the area of phase transformations in low carbon steels. It is well known that iron, Fe, exists in two forms; a high temperature form known as austenite and a low temperature form known as ferrite. The addition of alloying elements has been shown to have a strong effect on the kinetics of the transformation from austenite to ferrite on cooling. In spite of the great significance of this transformation, the mechanism by which the alloying elements affect the transformation is still poorly understood. The proposed work would involve highly controlled experiments which would permit us to better understand the effect of the alloying elements. Recent breakthroughs in the area of characterization at the atomic scale will be exploited in order to develop experimentally-validated phase-transformation models. ******The second area of interest is that of thermomechanical processing. The great interest in thermomechanical processes, such as hot-rolling, is due to the fact that these permit the refinement of the microstructure which, in turn, leads to improvements in strength and toughness. In the proposed work a series of experimental alloys will be investigated in order to determine key changes that occur within the microstructure during hot-rolling. Once these changes are understood, a physically-based model of multi-pass deformation will be developed and employed to optimize processing conditions. ******The third topic which will be investigated as part of this proposal is the engineering of microstructures at multiple length scales. In addition to the intrinsic scales within the microstructure, one can introduce new scales by introducing composition gradients (of the order of a millimetre) or by introducing architectured reinforcement (on the order of a centimeter). The proposed work will explore the potential of exploiting these length scales in order to produce materials with novel combinations of properties.***In total, 10 highly qualified individuals will be trained in areas of great importance to the Canadian industry. The graduates will be qualified to work in the steel, automotive and manufacturing sectors.********