Abstract The unique combination of very large strains, high temperatures and high strain rates inherent to friction stir welding (FSW) and friction stir processing (FSP) and their dependency on the processing parameters provides an opportunity to tailor the microstructure, and hence the performance of welds and surfaces to an extent not possible with fusion processes. While a great deal of attention has previously been focused on the FSW parameters and their effect on weld quality and joint performance, here the focus is on developing a comprehensive understanding of the fundamentals of the microstructural evolution during FSW/P. Through a consideration of the mechanisms underlying the development of grain structures and textures, phases, phase transformations and precipitation, microstructural control across a very wide range of similar and dissimilar material joints is examined. In particular, when considering the joining of dissimilar metals and alloys, special attention is focused on the control and dispersion of deleterious intermetallic compounds. Similarly, we consider how FSP can be used to locally refine the microstructure as well as provide an opportunity to form metal matrix composites (MMCs) for near surface reinforcement. Finally, the current gaps in our knowledge are considered in the context of the future outlook for FSW/P.

中文翻译：

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金属和合金的搅拌摩擦焊接/加工：微观结构演变的全面回顾

摘要 搅拌摩擦焊 (FSW) 和搅拌摩擦加工 (FSP) 固有的非常大的应变、高温和高应变率的独特组合及其对加工参数的依赖性提供了定制微观结构的机会，从而提高了材料的性能。焊接和表面达到熔合工艺无法实现的程度。虽然以前的大量注意力集中在 FSW 参数及其对焊接质量和接头性能的影响上，但这里的重点是全面了解 FSW/P 期间微观结构演变的基本原理。通过考虑晶粒结构和织构、相、相变和沉淀发展的潜在机制，检查了非常广泛的相似和不同材料接头的微观结构控制。特别是在考虑异种金属和合金的连接时，特别注意有害金属间化合物的控制和分散。类似地，我们考虑如何使用 FSP 局部细化微观结构，并提供形成金属基复合材料 (MMC) 以进行近表面增强的机会。最后，我们在 FSW/P 的未来前景的背景下考虑了我们目前的知识差距。我们考虑如何使用 FSP 局部细化微观结构，并提供形成金属基复合材料 (MMC) 以进行近表面增强的机会。最后，我们在 FSW/P 的未来前景的背景下考虑了我们目前的知识差距。我们考虑如何使用 FSP 局部细化微观结构，并提供形成金属基复合材料 (MMC) 以进行近表面增强的机会。最后，我们在 FSW/P 的未来前景的背景下考虑了我们目前的知识差距。