Industry 4.0 being the new face of manufacturing for future, metal additive manufacturing is a key element in this framework. For metal additive manufacturing, laser-based additive manufacturing techniques are dominating today. However, some of the inherent technical limitations associated with these techniques lead to a significant gap between the industrial requirements and the final deliverables. Additive friction stir deposition is a promising alternative that is still in its early stages of development. This review summarizes the vital findings in AFSD with particular emphasis on microstructure evolution and physical properties. The technical limitations of laser-based AM techniques are discussed to describe the role of AFSD in their domain. AFSD is discussed sequentially covering the basic physical process, features, capabilities, and limitations. AFSD, being a solid-state thermomechanical process, results in a refined equiaxed microstructure with enhanced mechanical properties and no signs of porosity and residual stresses. In addition to this, AFSD is capable of depositing large scale components at a high build rate that leads to cost and energy-efficient fabrication. The existing limitations of the process are discussed with the scope for future improvements. This critical review concludes with the suggested strategies for the widespread adoption of AFSD.

工业4.0是面向未来制造的新面孔，金属增材制造是此框架中的关键要素。对于金属增材制造，基于激光的增材制造技术在当今占主导地位。但是，与这些技术相关的某些固有技术局限性导致了工业要求和最终交付成果之间的巨大差距。加性摩擦搅拌沉积是一种有前途的替代方法，目前仍处于发展初期。这篇综述总结了AFSD的重要发现，特别着重于微观结构的演变和物理性质。讨论了基于激光的AM技术的技术局限性，以描述AFSD在其领域中的作用。依次讨论了AFSD，涵盖了基本的物理过程，功能，和限制。AFSD是固态热机械过程，可产生具有增强的机械性能且无孔隙和残余应力迹象的精细等轴微结构。除此之外，AFSD能够以高构建速率沉积大规模组件，从而导致成本和节能设计。讨论了该过程的现有局限性以及未来改进的范围。这篇重要的评论总结了AFSD广泛采用的建议策略。AFSD能够以高构建速率沉积大型组件，从而带来成本和节能的制造。讨论了该过程的现有局限性以及未来改进的范围。这篇重要的评论总结了AFSD广泛采用的建议策略。AFSD能够以高构建速率沉积大型组件，从而带来成本和节能的制造。讨论了该过程的现有局限性以及未来改进的范围。这篇重要的评论总结了AFSD广泛采用的建议策略。