Friction stir additive techniques (FSATs) constitute innovative approaches aimed at utilizing layer by layer additive manufacturing (AM) principle with solid state friction stir welding (FSW) technique. These constitute a special class of friction based additive techniques (FATs) and can be easily thought of as major breakthrough of metal additive manufacturing (MAM) domain. Ability of MAM techniques to be used for fabricating intricate parts has led them to be considered as a lucrative option for aviation, automotive, and marine sectors. However, fusion based MAM techniques have manifold limitations mainly owing to solidification related as well as poor shear strength issues. FATs overcome drawbacks of fusion based MAM methods chiefly because of their solid-state nature. FATs fabricate defect free components possessing superior structural and mechanical characteristics. Basic principles of additive manufacturing and FSW necessary for highlighting need and concept of FATs are introduced first. All FATs with their basic principles and specific merits are then presented. Special emphasis is given to two most effective FATs based upon FSW, i.e., FSATs which are friction stir additive manufacturing and additive friction stir (AFS). Aim of this work is to present a critical review of timeline and recent developments in the field of FSATs. In addition, challenges and future trends of these innovative techniques are highlighted followed by detailed discussion.

中文翻译：

---

固态摩擦基金属增材制造的最新进展综述：摩擦搅拌增材技术

摩擦搅拌添加技术（FSAT）构成了创新的方法，旨在利用固态摩擦搅拌焊接（FSW）技术利用逐层添加制造（AM）原理。这些构成了一类特殊的基于摩擦的添加技术（FAT），可以轻松地视为金属增材制造（MAM）领域的重大突破。MAM技术用于制造复杂零件的能力使它们被认为是航空，汽车和海运领域的有利可图的选择。然而，基于熔融的MAM技术主要由于与固化相关的以及剪切强度差的问题而具有多种局限性。FAT主要由于其固态特性而克服了基于融合的MAM方法的缺点。FAT可制造出具有优良结构和机械特性的无缺陷组件。首先介绍了增材制造和FSW的基本原理，以强调FAT的必要性和概念。然后介绍所有具有其基本原理和特定优点的FAT。特别强调了基于FSW的两种最有效的FAT，即FSAT，即搅拌摩擦添加剂制造和搅拌摩擦添加剂（AFS）。这项工作的目的是对FSAT的时间表和最新发展进行严格的审查。此外，重点介绍了这些创新技术的挑战和未来趋势，随后进行了详细讨论。然后介绍所有具有其基本原理和特定优点的FAT。特别强调了基于FSW的两种最有效的FAT，即FSAT，即搅拌摩擦添加剂制造和搅拌摩擦添加剂（AFS）。这项工作的目的是对FSAT的时间表和最新发展进行严格的审查。此外，重点介绍了这些创新技术的挑战和未来趋势，随后进行了详细讨论。然后介绍所有具有其基本原理和特定优点的FAT。特别强调了基于FSW的两种最有效的FAT，即FSAT，即搅拌摩擦添加剂制造和搅拌摩擦添加剂（AFS）。这项工作的目的是对FSAT的时间表和最新发展进行严格的审查。此外，重点介绍了这些创新技术的挑战和未来趋势，随后进行了详细讨论。