The question of the formation mechanism of annealing twins in face-centered cubic metals and alloys, which is still not resolved in spite of the fact that the existence of these defects is known for long, is addressed in this paper. The different mechanisms proposed through the years are reviewed. Most of them focus on coherent twin boundaries. However, incoherent twin boundaries are very frequent as well, notably in recrystallized microstructures and would definitely deserve more specific attention. Twin topologies are so much different after recrystallization and after grain growth that distinct names would be better suited than the general term of annealing twins. Because twins are at the core of most grain boundary engineering approaches, the mechanisms by which an interconnected network of twin and related boundaries can be formed are discussed, in the light of the current knowledge on annealing twin formation mechanisms. Finally, the state of the art of mesoscopic models and simulations able to account for twin boundaries is presented. Accounting for twins is a requirement since they not only play a role in microstructure evolution upon thermomechanical processing but also affect the in-service material behavior, positively or negatively depending on the involved properties.

本文解决了在面心立方金属和合金中孪晶退火的形成机理的问题，尽管这些缺陷的存在已为人们所知，但仍未解决。回顾了多年来提出的不同机制。他们大多数关注连贯的孪生边界。但是，非相干孪晶边界也很常见，特别是在重结晶的微观结构中，绝对值得引起更多关注。在重结晶和晶粒生长后，孪晶拓扑有很大不同，以至于与退火孪晶的总称相比，不同的名称更适合。由于孪晶是大多数晶界工程方法的核心，因此，根据对孪晶形成机理进行退火的现有知识，讨论了形成孪晶和相关边界的互连网络的机理。最后，介绍了能够解释孪生边界的介观模型和仿真技术。考虑孪晶是必需的，因为它们不仅在热机械加工过程中在微观结构演变中发挥作用，而且还取决于所涉及的特性，对使用中的材料行为产生积极或消极的影响。