Strength, deformation, fracture behaviour and ductility of aluminium-lithium alloys
Strength, deformation, fracture behaviour and ductility of aluminium-lithium alloys
复制标题
DOI：
10.1007/bf00585420
复制
发表时间：
1990-02
影响因子：
4.5
通讯作者：
E. Lavernia;T. Srivatsan;F. Mohamed
中科院分区：
文献类型：
--
作者：
E. Lavernia;T. Srivatsan;F. Mohamed
对高强度、高性能、轻质和低成本材料的需求不断增长，导致了用于结构应用的新型铝合金的显著改进和开发。锂添加到铝中有可能提供一类具有特殊性能的高强度合金，适用于重量临界应用。在本文中，已发表的研究组成-加工-微观结构的关系进行了讨论。的固溶体的强度的贡献进行了讨论参考的存在下，在固溶体中的锂，在基体中的连贯的，有序的沉淀物和共沉淀的二元，三元和更复杂的强化相的存在下。显微组织对强度的影响进行了讨论，参考冶金变量。这些变量包括内在的微观结构特征;弥散体的存在、基体强化沉淀物的性质和类型以及晶界附近洁净区的存在。外在和内在的微观机制的变形特性和断裂行为的严格审查与具体参考合金的时效条件，基体滑移特性，和强化析出物的性质，体积分数和分布。应变局部化的有害影响和加剧无沉淀区的影响也被强调。断裂过程中的微观力学检查和事件的顺序在断裂过程中进行审查的具体作用，涉及的性质和体积分数的第二相粒子，变形模式，和位错微观结构的相互作用的几个并发因素。过去的尝试，以提高这些合金的拉伸延展性和机械响应也进行了检查，以便提供一个更好的基础，了解加工-微观结构-变形的相互作用。
The ever increasing need for high strength, improved performance, lightweight and cost-effective materials has resulted in significant improvements and development of new aluminium alloys for structural applications. Lithium additions to aluminium have the potential for providing a class of high strength alloys with exceptional properties suitable for weight-critical applications. In this paper, published studies of composition-processing-microstructure relationships are discussed. Contributions to strength of the solid solution are discussed with reference to the presence of lithium in solid solution, the presence of coherent, ordered precipitates in the matrix and the co-precipitation of binary, ternary and more complex strengthening phases. Microstructural influences on strength are discussed with reference to metallurgical variables. These variables include the intrinsic microstructural features; the presence of dispersoids, the nature and type of matrix strengthening precipitates and the presence of denuded zones adjacent to grain boundaries. The extrinsic and intrinsic micromechanisms governing the deformation characteristics and fracture behaviour are critically examined with specific reference to ageing condition of the alloy, the matrix slip characteristics, and the nature, volume fraction and distribution of strengthening precipitates. The deleterious effects of strain localization and the exacerbating effect of precipitate-free zones are also highlighted. The micromechanics governing the fracture processes are examined and the sequence of events in the fracture process is reviewed in light of the specific role of several concurrent factors involving nature and volume fraction of second-phase particles, deformation mode, and dislocation-microstructure interactions. Past attempts made to improve the tensile ductility and mechanical response of these alloys are also examined so as to provide a better basis for understanding processing-microstructure-deformation interactions.