Review on latest trends in friction-based additive manufacturing techniques

Additive manufacturing comprises layer-by-layer construction of 3D parts using computer controls. This present-day study reveals a list of novel concepts for additive manufacturing, where the addition of material is achieved in solid-state. Materials joined by solid-state techniques exhibits properties beyond those exhibited by material joined by conventional techniques. This has been investigated in both theoretical and experimental manner in length. However, with the development of additive manufacturing techniques, a wide range of possibilities for fabricating complex structures have been identified, which can never be accomplished by conventional techniques. Research on metal-based additive manufacturing has been comparatively less as these products deprive lateral and transverse strength and have issues of anisotropy, making them unfit for structural applications. Moreover, these techniques are not cost-effective. So to overcome these issues, methods incorporating friction into additive manufacturing have been developed. These solid-state techniques use the principle of layer-by-layer deposition. Most of these techniques utilize the principle of selective deposition of materials to form the desired material layer. In this literature review, different advances, approaches, features, and principles of friction-based material joining techniques alongside additive manufacturing are discussed in detail, which recommends new openings for researchers to work in interdisciplinary research to fabricate structures that can exhibit unique properties. This literature portrays an extensive account of the contemporary methods in the fabrication of structures using friction-based additive manufacturing techniques and highlights areas that are worth further research and necessitate a consistent effort on account of the aforementioned disciplines to advance the modernistic technique. Initially, a brief review of different solid-state additive manufacturing techniques is presented, followed by a comprehensive summary of friction stir-based additive manufacturing techniques such as friction assisted seam welding (FASW), additive friction stir (AFS) process, and friction stir additive manufacturing (FSAM) process.